tag:blogger.com,1999:blog-75766612933989231452024-03-18T23:00:15.903-05:00Heartland SkiesGrant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.comBlogger261125tag:blogger.com,1999:blog-7576661293398923145.post-84342078060247670112014-12-10T22:30:00.001-06:002014-12-10T23:07:42.373-06:00Surprise.......SLEET!!!!!<div class="separator" style="clear: both; text-align: left;">
A weak disturbance moved through Heartland this evening and produced a little surprise for a few, sleet. This system moved into very dry air and was forecast to die out before making it into our area. The image below is from the forecast sounding for Cape Girardeau, a profile of the atmosphere. The red line indicates the air temperature as you move up the atmosphere, the green line shows the dew point. The larger the difference between the two, the drier the air. This sounding showed very dry air. The dark blue line is the freezing line. You can see as you move up in the atmosphere the air temperatures warmed above freezing. More on this later.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghb_isR4659u322olXEfAcXKfoldDG2m_mr9QBAm3flXunyQ0s7pLOXGHt_Xv3T05dNTZ39lxWSOa7WREZDfa-hRe-zg796KR1dCRv-u-FY0I-GzOVsH1ynsxr-2_sbtkRxMDxqiBcRqc/s1600/tonihgts+sleet.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghb_isR4659u322olXEfAcXKfoldDG2m_mr9QBAm3flXunyQ0s7pLOXGHt_Xv3T05dNTZ39lxWSOa7WREZDfa-hRe-zg796KR1dCRv-u-FY0I-GzOVsH1ynsxr-2_sbtkRxMDxqiBcRqc/s1600/tonihgts+sleet.png" height="360" width="640" /></a></div>
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As the precipitation moved into the area it encounters that warm level of above freezing temperatures. This of course causes the snow to melt. Now with the new Dual Pol Doppler Radar we can see when the snow begins to melt. The sleet shower was moving between Poplar Bluff and Dexter at the time of the image below. Notice most of the colors here showing a dark red color. This indicates the precipitation falling is all of the same type. Since the radar beam was hitting the shower at an altitude of 7,500 feet here, it was below freezing and all snow.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0EnXCHrg8XazacSftCgiLg84ZZo9dUKovwzlZUXICZ0Yu6yeTJw-5kfS3eOuSLeM5-Oo8Y6TzKGjNnEGFZ9vMsGXuHhteexORoECn1CftTX2a41LOKmZ997SKVqp70csgboi0d9VALI0/s1600/cc+1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0EnXCHrg8XazacSftCgiLg84ZZo9dUKovwzlZUXICZ0Yu6yeTJw-5kfS3eOuSLeM5-Oo8Y6TzKGjNnEGFZ9vMsGXuHhteexORoECn1CftTX2a41LOKmZ997SKVqp70csgboi0d9VALI0/s1600/cc+1.png" height="360" width="640" /></a></div>
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The next image sampled the shower from an altitude around 5,800 feet. Here we have a mix of yellow and dark red. The yellow colors indicate different types of precipitation in the shower. Since the precipitation was all snow at 7,500 feet and seeing that warm nose of air from the sounding, we know snow is melting so this radar image shows rain and snow mixed. The warm nose was thick enough to allow for the snow flakes to melt so when the precipitation fell out of the cloud, it was rain with a tiny bit if ice left in the center.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1fmYfKD9BWtfZd59DQwKKi03O2yb-6Yw7o8cUDILw_5kJOATxdJSdH-Q0PoRmWE7Fst4cpmrwA0hXZO2ZRaHkKugOlsZlQIye0A7AiJotI5oqS_1c9Zw5lKssiPTgjjcpRWpnt_O8kPI/s1600/cc+2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1fmYfKD9BWtfZd59DQwKKi03O2yb-6Yw7o8cUDILw_5kJOATxdJSdH-Q0PoRmWE7Fst4cpmrwA0hXZO2ZRaHkKugOlsZlQIye0A7AiJotI5oqS_1c9Zw5lKssiPTgjjcpRWpnt_O8kPI/s1600/cc+2.png" height="360" width="640" /></a></div>
In addition to being warm, the air is very dry. so as these drops of rain fall through the dry air they begin to evaporate. As this happens a process called evaporational cooling takes place as the drops cool to the wet bulb temperatures. Because the air was so dry the wet bulb was below freezing. So the drops will refreeze on the way to the surface, even if the air temperatures is above freezing. But in this case the air temperature briefly drops below freezing again as well so there was no problem in seeing drops freeze into sleet. Weather is always fun!Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-3283868492533468622014-05-27T17:23:00.001-05:002014-05-27T17:53:14.883-05:00Sunday Afternoon Landspout<div class="separator" style="clear: both; text-align: left;">
Sunday afternoon around 3:00PM a tornado spun up in Dunklin county just west of the intersection of HWY 102 and HWY 25 north of Malden. </div>
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='400' height='333' src='https://www.blogger.com/video.g?token=AD6v5dyBrnuPN-sY7enM5tsJlKX0HsWDEBTDrzNQfQg5s_M7Ksnyjj0MYLTExvtVfMBYOco9TRZ4alhHTtPeF5xNOQ' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div>
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Tornadoes usually form with rotation severe thunderstorms
and usually have a few minutes warning time before they develop. But there is one type of tornado that usually
develops quickly and without warning.
That type of tornado is called the landspout. A landspout tornado forms much in the same
way its cousin the waterspout develops over the water. Instead of a rotating severe thunderstorm in
which rotation form the mid levels is brought down to the surface, these tornadoes
start as a swirl on the ground that is stretched under a storm’s updraft. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTvEGoWX5fcpDIrHCUfmDeIcAw92TKv61536gYSUrxhxDKFSx39pTFe5_OEHtVu1jxFVtyIWz3X1PGlkch3rjT57bhbki2DYZiGc_hyAEn1ZazmjgLV-86GxBNhQ8R27pwxeeEnFN_5-Q/s1600/landspout+3.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTvEGoWX5fcpDIrHCUfmDeIcAw92TKv61536gYSUrxhxDKFSx39pTFe5_OEHtVu1jxFVtyIWz3X1PGlkch3rjT57bhbki2DYZiGc_hyAEn1ZazmjgLV-86GxBNhQ8R27pwxeeEnFN_5-Q/s1600/landspout+3.jpg" height="300" width="400" /></a></div>
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Two dust swirls on the ground. Photo Leslie Asher.</div>
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Sunday afternoon there was a thundershower located over
Dunklin County that collapsed around 2:40PM sending a boundary of rain cooled
air across the Bootheel. Along and immediately
behind this boundary little eddies or swirls form. Picture your arm moving along the top of the
water in a swimming pool. Right behind
your arm you will see little swirls form.
This same action occurs in the atmosphere as boundaries move
through. </div>
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='400' height='333' src='https://www.blogger.com/video.g?token=AD6v5dw-9kF782hQKSl-O7Ea68Zc1fQ8qTHNczu1n2EF0itL0qylNoVUIBKweoEQP4-3EpedfNiM3BiT7l7Hc2442Q' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div>
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Video above from Brandon Shelton.</div>
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As the boundary approached Malden a thundershower was
rapidly developing. This thundershower’s
updraft encountered the swirls on the ground stretching them making the
rotation stronger. The stretched
rotation is pulled into the thundershower’s updraft and a tornado forms. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsicoBYLfK5mI-t6sWBHpq41VYCJj1nE39_DKU2RSk1OSbQCa-yhXAGGSeE7iJ_ow9AUdxIXqjBiOKus-h693AzHC_KZj8TKrqTqMIji2hrJWucYeXqzVQjUGEbPhiramD6OQXcCQvWio/s1600/landspout+1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsicoBYLfK5mI-t6sWBHpq41VYCJj1nE39_DKU2RSk1OSbQCa-yhXAGGSeE7iJ_ow9AUdxIXqjBiOKus-h693AzHC_KZj8TKrqTqMIji2hrJWucYeXqzVQjUGEbPhiramD6OQXcCQvWio/s1600/landspout+1.jpg" height="300" width="400" /></a></div>
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Dust Swirl stretched into the storm. Photo Leslie Asher.</div>
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Now landspouts are usually very weak, EF0, but in some cases
have reached EF3 strength depending on the storm’s updraft strength. Looking at the video seen these were very
weak, maybe technically not reaching the 65MPH wind speed needed to be classified
as an EF0 tornado. But with that said
anytime there is a rotating column of air in contact with a storms updraft by
definition, it’s a tornado. Not sure if
this will go down as an official tornado but to all who sent video and photos
to help me investigate, thanks. You can
tell all your family and friends you saw a tornado. </div>
<br />Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-74849118243487902912014-05-15T12:54:00.000-05:002014-05-15T12:57:59.594-05:00Hail Possible Today<div class="separator" style="clear: both; text-align: left;">
Although temperatures are below average for this time of the year we are still expecting a few hail showers this afternoon. Right now it does not look as though we will see much in the way of severe hail, quarter size or larger, but a few thundershowers will contain a lot of pea size hail, and in some places could cover the ground. So why are we seeing a threat of hail when in May cooler temperatures usually mean no storms?</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQnVPN1Ps4MGHVJKDx6QzxJyZoe-HnqRM_V7MYXp0QhRv6BMDjGAsgnBYaL8PZ-vgGlxgB4NsZDMVrAOdO27JWZfhyphenhyphenhQD1aLTeewmHuypr_6l9SVHeWSL5tykVxq7G7a7Vz_XxcCDqjhQ/s1600/Screen+Shot+2014-05-15+at+11.41.31+AM.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQnVPN1Ps4MGHVJKDx6QzxJyZoe-HnqRM_V7MYXp0QhRv6BMDjGAsgnBYaL8PZ-vgGlxgB4NsZDMVrAOdO27JWZfhyphenhyphenhQD1aLTeewmHuypr_6l9SVHeWSL5tykVxq7G7a7Vz_XxcCDqjhQ/s1600/Screen+Shot+2014-05-15+at+11.41.31+AM.png" height="298" width="400" /></a></div>
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The satellite above shows what the Heartland looked like from space around 11:30 this morning. We see lots of sunshine but we are also seeing cumulus clouds developing across our northwestern counties. These are the clouds that will grow into thunderstorms. The reason is because there is an area of very cold temperatures in the mid levels of the atmosphere, around -15 degrees, moving across much warmer air at the surface. This causes the air to rise rapidly which leads to thunderstorm development.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVMC4Hxlb8xy5TQSVwdS47FIGJK6CYRAC8v8oqI2zOOm7IG1NwBIqBVXV9JjRGuxS9UgOeZiruUwUwOjdurlNvFR8JZo61wmWp5KRSRE9gpqoi9ZgByPlRRMbUmJyYzZS9mQHf5f-Vue8/s1600/Screen+Shot+2014-05-15+at+11.44.04+AM.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVMC4Hxlb8xy5TQSVwdS47FIGJK6CYRAC8v8oqI2zOOm7IG1NwBIqBVXV9JjRGuxS9UgOeZiruUwUwOjdurlNvFR8JZo61wmWp5KRSRE9gpqoi9ZgByPlRRMbUmJyYzZS9mQHf5f-Vue8/s1600/Screen+Shot+2014-05-15+at+11.44.04+AM.png" height="298" width="400" /></a></div>
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Above is a profile of the atmosphere, a skew-T diagram. The blue line represents the temperature of the air as it is lifted. The red line is the actual air temperature. The area between the blue and red lines where the blue line is on the right represents the amount of CAPE (convective available potential energy) for thunderstorms development. At first glance it is not very impressive. We call this a short skinny CAPE which usually leads to a few scattered showers. But a closer look shows that most of the CAPE lies in an area where temperatures are below -10°C or the hail growth region. So hail will form very easily in these showers. But since it is a skinny CAPE, the updraft of the storm will be weak meaning the hail will not be able to grow to a very large size. As of this writing we have already seen pea size hail across parts of central Missouri and I expect that to increase as the afternoon progresses. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgupSz0hymSWPPCx0i7ldUPvV39OwMvMWCE3C3eWEl4oka2xs8UAeJaZLmfMOQ9qyUUlglBYjFCmHwtICIPi38Z-gBqMIgrC5RI0VM2zjJlxf_6OicXYGrIaPvtiaEMM-smtnCHSaVAVP8/s1600/Screen+Shot+2014-05-15+at+11.45.11+AM.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgupSz0hymSWPPCx0i7ldUPvV39OwMvMWCE3C3eWEl4oka2xs8UAeJaZLmfMOQ9qyUUlglBYjFCmHwtICIPi38Z-gBqMIgrC5RI0VM2zjJlxf_6OicXYGrIaPvtiaEMM-smtnCHSaVAVP8/s1600/Screen+Shot+2014-05-15+at+11.45.11+AM.png" height="287" width="400" /></a></div>
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The above image shows a forecast for where storms should be around 4PM. Don't pay attention to the exact location, just note there will be scattered thunderstorms with small hail throughout the Heartland later this afternoon. So a few areas of the Heartland will experience hail today. You may want to keep the car in the garage if possible even though damaging hail is not anticipated. If the small hail is heavy enough it could chip some paint.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-71264286824115444912014-05-05T09:34:00.003-05:002014-05-05T09:34:49.127-05:00Hot Day to Fish Yesterday<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRfT5F3-y7BhzrsBk6O-rBW3Ff2qsH44OBfFbLcgf73wi7r_EN_T4ImEt-832UfF0GdAejtK9Tf5b1gCV4wfjH07a-OmOJTo3_ANXrck8EjmyZ8zSTqdZ5Y-5HtMyVFJUka2BuBwJCbEc/s1600/photo+(23).JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRfT5F3-y7BhzrsBk6O-rBW3Ff2qsH44OBfFbLcgf73wi7r_EN_T4ImEt-832UfF0GdAejtK9Tf5b1gCV4wfjH07a-OmOJTo3_ANXrck8EjmyZ8zSTqdZ5Y-5HtMyVFJUka2BuBwJCbEc/s1600/photo+(23).JPG" height="300" width="400" /></a></div>
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Fished the Castor and ST. Francis Rivers yesterday as the temperature hit the 90 degree mark. The Castor is amazing and clear. I plan on floating this river next month. Lots of fish, just none biting. I saw my first smallmouth yesterday in the Castor River under Highway 72, just couldn't get hime to bite. Still trying! Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-5833988538211686942014-05-04T12:13:00.001-05:002014-05-04T12:13:28.920-05:00Still Hunting For My First Smallmouth <div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjd5jD-wdY0F34-ZNpqQkc_XHq8bMRcNSCOPwHhCiSUyO9wYy1Yux9jIOYJreSSJ6GU1PVppSewuE1DR8mFhF6MXjlNqoFa9DgllMkRdV3k8jTUfp8lhdkf3v0YJKgOtvq5UhuPNDq3YdA/s1600/photo+(22).JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjd5jD-wdY0F34-ZNpqQkc_XHq8bMRcNSCOPwHhCiSUyO9wYy1Yux9jIOYJreSSJ6GU1PVppSewuE1DR8mFhF6MXjlNqoFa9DgllMkRdV3k8jTUfp8lhdkf3v0YJKgOtvq5UhuPNDq3YdA/s1600/photo+(22).JPG" height="300" width="400" /></a></div>
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I stalked Little Whitewater Creek yesterday in an area recommended by co-workers to try and catch my first small mouth. I went with my 6wt fly rod and started with a crayfish imitation. Second cast was a hook up. A small but fun spotted bass. I thought to myself, "this was going to be a great day." Well, I did catch a number of small fish in the sunfish and shad variety, but no small mouth. I did see many nice size spotted bass in this creek so I will be back. my search continues............Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-2015310162516266612014-05-02T17:06:00.000-05:002014-05-02T17:40:14.346-05:00Woodland Mills Tornadic Mini Supercell<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDKJYVXHDV6tnlcjW7wDx2tVECGAdphKSzi391v9cAfcp41b7ZqHkTFQ0nTrOdDM8yk8YU8HdzH6cLEJZfdcFrV5vK8VmmZEgNgPy4gW8cx6BbUGSedGXPL1f4S_lwT6Efkev6vPNFKTY/s1600/union+city+tenn.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDKJYVXHDV6tnlcjW7wDx2tVECGAdphKSzi391v9cAfcp41b7ZqHkTFQ0nTrOdDM8yk8YU8HdzH6cLEJZfdcFrV5vK8VmmZEgNgPy4gW8cx6BbUGSedGXPL1f4S_lwT6Efkev6vPNFKTY/s1600/union+city+tenn.jpg" height="225" width="400" /></a></div>
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(Photo source above Ben Yates FaceBook)</div>
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Sunday and Monday were very active weather days across the Heartland with severe weather and flooding. Monday afternoon parts of the Heartland were under consideration for a tornado watch but, one was never issued. Conditions were favorable for tornadoes if deep convection(strong thunderstorms) could occur. All afternoon small thunderstorms developed showing weak signs of rotation as the atmosphere was extremely sheared. Around 5PM a thunderstorm rapidly developed to the south of Union City, TN and would go on to produce a very strong EF2 tornado (top winds 130MPH) with out warning. This type of storms is called a mini supercell, a small cousin of the usual large severe storms we see produce tornadoes across the Heartland.</div>
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The image above is what the storm appeared like on Doppler Radar as the tornado was on the ground. At first glance it does not appear very strong at all. Our lightning detection was showing a few bolts to the north but at this time this storm was not very electrical, another sign of a weak storm.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-rkE8XD-Mq-NIBDO4hoxmHPcCReXp8UAZKFe-XDA2WsOrk25NjcJg5AmODfo5xf77BVBGXA3fH0BDF0JiEC8ruzo3YQ2xi5jG7WBl2OR-8YCZkbZByVE_sRcknxkH8HPq9xTBYaXKWnE/s1600/C%253a%255cUsers%255cbmccormick%255cPictures%255cwoodland+mills+volume.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-rkE8XD-Mq-NIBDO4hoxmHPcCReXp8UAZKFe-XDA2WsOrk25NjcJg5AmODfo5xf77BVBGXA3fH0BDF0JiEC8ruzo3YQ2xi5jG7WBl2OR-8YCZkbZByVE_sRcknxkH8HPq9xTBYaXKWnE/s1600/C%253a%255cUsers%255cbmccormick%255cPictures%255cwoodland+mills+volume.png" height="215" width="400" /></a></div>
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The three dimensional view the tornadic storm shows a small core not even reach 20,000' into the atmosphere. The red colors which show heavy rain and hail are barely above 12,000' at this time. normally we see cores to 50,000' on storms that produce tornadoes. So what made this small storm produce such a strong tornado for its size? I had to know and decided to take a closer look.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEih23gK2lNinvevlVU1XTMeaBfb1ucYEpb7-O3iuvaEFg7VKniR6V2eMaHA0KylYabyNsWNnuAkmIEXQ-T2udRiDWzsqbFfa2soJJPt5QrvZ8exOennBe_T5WC1EQd43tJLTLg5vFIMpgg/s1600/NAM_218_2014042818_F27_36.0000N_89.0000W.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEih23gK2lNinvevlVU1XTMeaBfb1ucYEpb7-O3iuvaEFg7VKniR6V2eMaHA0KylYabyNsWNnuAkmIEXQ-T2udRiDWzsqbFfa2soJJPt5QrvZ8exOennBe_T5WC1EQd43tJLTLg5vFIMpgg/s1600/NAM_218_2014042818_F27_36.0000N_89.0000W.png" height="400" width="383" /></a></div>
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The image above is a skew-t diagram from the 22:00Z (CDT +5 hours) hour RUC near Union City to get as close to the storm's environment as I could. In the above forecast sounding there is enough CAPE (Convective Available Potential Energy) for surface based thundershowers to develop. Overall it is pretty weak and this typically wouldn't throw out the "red flag" that something bad is about to happen. So we need to look a little deeper.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8J8o2UKUTKTzPPZVzkCat92v2oB-txICDJxXnUI4pAwiBz2DB0Pw3Ifl8X_QtkmnRTkS83HWbdzOqr2NOd8qIYQ99M2oLGNfUB94Lx0Kc7Bgy1AZuHxIqSbiy_20jJAfK0Ery5zRKbSo/s1600/NAM_218_2014042818_F27_36.0000N_89.0000W_HODO.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8J8o2UKUTKTzPPZVzkCat92v2oB-txICDJxXnUI4pAwiBz2DB0Pw3Ifl8X_QtkmnRTkS83HWbdzOqr2NOd8qIYQ99M2oLGNfUB94Lx0Kc7Bgy1AZuHxIqSbiy_20jJAfK0Ery5zRKbSo/s1600/NAM_218_2014042818_F27_36.0000N_89.0000W_HODO.png" height="400" width="400" /></a></div>
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The image above is the hodograph from the 22:00Z (5PM CDT) hour RUC near Union City, TN. Here the large clockwise curve indicated an enormous amount of shear in the atmosphere, or spin to cause thunderstorms to rotate. Most of the shear is occurring in the same area of the atmosphere we see the positive CAPE. So any thundershower that could develop in this environment would more than likely become a supercell, or mini supercell in this case. Not shown is the 0-1KM bulk shear, or the difference between the surface wind speed and the 1KM wind speed. At the time of this storms the 0-1KM bulk shear was around 30 knots. Any value above 20 knots is favorable for tornado development. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCnHlcbXCP4TwnoV2gAJ4rcEB5tBxk-FHaQrjVW8aNlXEhsHf6sTYF2koGk8FcGbPKvbSR3oSa04G_wb9T_-n7BXrUAUXWAZl0mEskO7Jb2tEhJVjZjZ1JIZKtEBAfq8ndDMCxounPEIg/s1600/C%253a%255cUsers%255cbmccormick%255cDesktop%255cwoodland+mills%255cvel.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCnHlcbXCP4TwnoV2gAJ4rcEB5tBxk-FHaQrjVW8aNlXEhsHf6sTYF2koGk8FcGbPKvbSR3oSa04G_wb9T_-n7BXrUAUXWAZl0mEskO7Jb2tEhJVjZjZ1JIZKtEBAfq8ndDMCxounPEIg/s1600/C%253a%255cUsers%255cbmccormick%255cDesktop%255cwoodland+mills%255cvel.png" height="226" width="400" /></a></div>
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We have already seen what the storm looked like on radar and in 3D. Now let's see what the storm's velocity data was showing, or the winds inside the storm. The image above shows an area of bright green next to an area of brighter red. The bright green indicates winds moving towards the radar at 35 knots. The red colors show winds moving away from the radar at 29 knots. This rotation is indicating a mesocyclone, a rotating thunderstorm. This storm showed a mesocyclone, although weak, for up to 15 minutes before the tornado was produced. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKvW6j17-iLY3HjtQCb5cI6RmobyleswTJTVdkDHT37tb6utIgiDSJwRkglygAhJA_Vqpwd-GGq8VUUIzGSnn1xYOIDJoTflBypIpqK_06x1F8Omloy0jiN-6TRMAQUsMMI5MCogl90yw/s1600/Woodland+Mills+Mesocyclone+Chart.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKvW6j17-iLY3HjtQCb5cI6RmobyleswTJTVdkDHT37tb6utIgiDSJwRkglygAhJA_Vqpwd-GGq8VUUIzGSnn1xYOIDJoTflBypIpqK_06x1F8Omloy0jiN-6TRMAQUsMMI5MCogl90yw/s1600/Woodland+Mills+Mesocyclone+Chart.jpg" height="400" width="640" /></a></div>
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So we now there was a mesocyclone so why was no warning issued? Well to be honest, the mesocyclone was never that impressive on radar in terms of strength to produce a tornado. The chart above shows the comparison to rotational velocity [the absolute value of the inbound plus the absolute value of the outbound velocities divided by two or Vr= (|Vi|+|Vo|)/2] to the range from Doppler Radar. The red dots on the chart show the time of the sampled mesocyclone and its strength, with the time moving from right to left. Notice as the storm gets closer to the time it produces the tornado, the mesocyclone gets stronger but never more than a minimal mesocyclone strength. SO no warning was issued. But the above chart does not take into consideration the size of the mesocyclone, or the diameter. Since mini supercells are much smaller in size than classic supercells, the diameter of their mesocyclone is usually much smaller as well.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFEPjcyuVYsya_q2RyEkxsXmNYki2Dryy0FFoDzONeqyxvcI_Uzc79TohPBuENEwdEdNGzMhl9ouhyphenhyphen76alvUQvFlUwEvVFj7x5-Rr3da0c8Dj9tk0HgpnKDVhgxw5upA1onN379IDMKr8/s1600/VR+vs+SR+chart.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFEPjcyuVYsya_q2RyEkxsXmNYki2Dryy0FFoDzONeqyxvcI_Uzc79TohPBuENEwdEdNGzMhl9ouhyphenhyphen76alvUQvFlUwEvVFj7x5-Rr3da0c8Dj9tk0HgpnKDVhgxw5upA1onN379IDMKr8/s1600/VR+vs+SR+chart.jpg" height="250" width="400" /></a></div>
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Research performed by <a href="http://www.srh.noaa.gov/images/shv/resourcelibrary/Nomogram98.pdf">Kenneth Falk and William Parker</a> from the Nation Weather Service in Shreveport, LA in 1998 showed that looking at the Rotational Shear (Sr=2(Vr)/D where D is the diameter of the mesocyclone in meters) which takes into consideration the diameter of the mesocyclone may be a better determination in whether a storm will produce a tornado. The above chart shows the Sr*10^3 with values in orange showing a tornado is possible and in purple showing a tornado is probably. Notice the depth of the mesocyclone is lower than 10,000' for most of the observations. Normally we would see mesocylone depth greater than 10,000' but again with this being a mini supercell, everything is much smaller. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3_W3J2K3rxRP36m1P0TsQo8sYhUH_JWOLrwXiTv2Ydbk7hJQCVlKqF-XgdqAuGhlG04Uc44Dx2s6S-BfT88alhW2qi6WyCuWvF083tOtViWzTg7Ho6JMN8_Gslfh_agS6f3Zb8xJJVJA/s1600/Woodland+Mills+Rotational+Shear+Chart.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3_W3J2K3rxRP36m1P0TsQo8sYhUH_JWOLrwXiTv2Ydbk7hJQCVlKqF-XgdqAuGhlG04Uc44Dx2s6S-BfT88alhW2qi6WyCuWvF083tOtViWzTg7Ho6JMN8_Gslfh_agS6f3Zb8xJJVJA/s1600/Woodland+Mills+Rotational+Shear+Chart.jpg" height="400" width="640" /></a></div>
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The above chart is from Falk and Parker's study in which they examined 50 mesocyclones to determine when a tornado is more likely. Again the time line of the Woodland Mills storm goes from right to left. With the rotational shear showing a tornado is probably and the near storm environment likely for tornado development, we will be looking to use this guideline more as we go through severe weather events. Right now we do not have a way this for this information to be generated automatically but it is mathematically possible for us to perform these calculations during sever weather events.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-81725199322784249322012-12-17T16:27:00.001-06:002012-12-17T16:27:29.203-06:00Severe storms possible Wednesday<br />
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A strong area of low pressure will develop along a cold
front and move across East Texas Wednesday evening. As it moves towards East Texas scattered
strong storms will develop Wednesday night.
Right now the best timing on the front’s arrival is around Midnight Wednesday
Night Thursday morning. Behind this front, strong northwesterly winds
will usher in some fairly chilly weather for the end of the week.</div>
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Right now the greatest threat of severe weather appears to
be strong gusty as the mid level flow across East Texas will be between 70 and
90 miles per hour. The taller storms
will be able to tap some of this wind and bring it down to the surface. So it does appear likely the stronger storms
will be able to produce winds of up to 80 miles per hour across East Texas late
Wednesday night in to Thursday morning.
So start to plan now to remove loose objects from the yard and maybe the
inflatable yard Christmas decorations just in case.</div>
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The overall threat of tornadoes right now appears rather
low. There will be a lot of low level
shear favorable for tornado development but with surface winds remain out of
the southwest ahead of the front, the amount of low level spin for tornado
development appears less favorable.
There maybe one or two brief weak tornadoes but at this time the winds
damage threat appears to be the greatest across East Texas. Stay tuned for the latest developments. </div>
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Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-37906239403433994092012-12-07T11:50:00.003-06:002012-12-07T11:50:16.245-06:00Very Active Weather Pattern The Next Few DaysA strong polar front is diving south towards East Texas this weekend and will provide some active weather that includes a chance of rain, storms, and maybe even a flurry or two across parts of East Texas. For all the snow lovers out there, don't get too excited because it probably won't happen but, the chance is not zero. Here is what looks like may happen this weekend as of Friday morning.<br />
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Right now a weak cool front is located across north central Texas with an area of low pressure developing west of the Hill Country. This front will drift towards the I-20 corridor before washing out Saturday night. Now the forcing along this front providing lift is fairly weak but, there looks as though enough instability will develop across East Texas to where a thunderstorm or two could develop Saturday afternoon. The atmosphere will be conducive for a severe thunderstorm or two as surface based instability will be sufficient for robust updrafts which could produce hail. Surface based Lifted Index will be negative, approaching -5, allowing for strong updrafts to develop.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjE0AZhmgGv8sbMcCY6BTD3JZpmD4PJAn5Am3Y-oQYZe6Nq8nCjYQ2ZabBXGd5B5rtZ3DjhauecKesNghA-QG0PCSMi-VGelX1UfdkJWIUzxIk-vD6nTunt2IRwdpN8mzh1PGSDDrXdWpw/s1600/wrfSP_2_dewp_33-1.gif" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjE0AZhmgGv8sbMcCY6BTD3JZpmD4PJAn5Am3Y-oQYZe6Nq8nCjYQ2ZabBXGd5B5rtZ3DjhauecKesNghA-QG0PCSMi-VGelX1UfdkJWIUzxIk-vD6nTunt2IRwdpN8mzh1PGSDDrXdWpw/s640/wrfSP_2_dewp_33-1.gif" width="640" /></a></div>
The winds throughout the atmosphere on Saturday appear as though they will be out of the southwest limiting the tornado threat. The shear will be strong enough for an isolated supercell or two mainly along and north of I-30 Saturday afternoon so if there were to be an isolated storm that becomes severe this would be the most likely location.<br />
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On sunday a much stronger front will move towards the area allowing for a line of scatter thunderstorms to develop on move southeast across East Texas. Like Saturday, the surface based instability will be more than enough for robust updraft development as the surface based lifted index will range between -4 and -6 across East Texas.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNnKHF_dIixiFjvtoSu6s-E_VGoVbV_coBZcOnPrDHOvE2jpOb9khUo-kFUz5kNRy6r-sAeKqoGnotb_iXtwZPd-FZLCaAb0CFUTA4Bxm4XlC1wI3C-AshPwATr3PTz3ZGPAQMLy1DyP4/s1600/wrfSP_2_dewp_57.gif" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNnKHF_dIixiFjvtoSu6s-E_VGoVbV_coBZcOnPrDHOvE2jpOb9khUo-kFUz5kNRy6r-sAeKqoGnotb_iXtwZPd-FZLCaAb0CFUTA4Bxm4XlC1wI3C-AshPwATr3PTz3ZGPAQMLy1DyP4/s640/wrfSP_2_dewp_57.gif" width="640" /></a></div>
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Now unlike Saturday, the shear across east texas will be more than enough for supercell development. 0-6km bulk shear will be around 50 knots which will allow for the atmosphere to provide enough shear for rotating updrafts increasing the threat of large hail.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEXzVdWKogb8qW2jK3_2GBBYSoFCX1DvMr2-0u7CzoGCXj6jTw-4x-rAyKMoiVe8FndyYr9oi8XiJLvCI-fxhVEOosgiyVy6v3LLnsOXCd3sEhv5qlFQ0FevGznHa4bDA2ac63MUBGtTw/s1600/NAM_221_2012120712_F57_SHRM_500_MB-1.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="458" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEXzVdWKogb8qW2jK3_2GBBYSoFCX1DvMr2-0u7CzoGCXj6jTw-4x-rAyKMoiVe8FndyYr9oi8XiJLvCI-fxhVEOosgiyVy6v3LLnsOXCd3sEhv5qlFQ0FevGznHa4bDA2ac63MUBGtTw/s640/NAM_221_2012120712_F57_SHRM_500_MB-1.png" width="640" /></a></div>
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The low level shear however will not be supportive for tornado development. Again the winds throughout the atmosphere will be mainly out of the southwest limiting the low level spin available for low level mesocyclone development. The 0-1km bulk shear will be around 10 knots which is not the optimum level for tornado development. Although not unheard of the overall tornado threat will these perimeters is fairly low. <br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-aqm-Cw5DSgGMJ5P9ZiGjWtfFq9kvrrWksgka4yWDtO3yh7ci_a3ouETdujoggNTltYD07pq8fk5Z0WnCLNeRO0nzADibzziQqrg3Dmh0AC0iNOEwqNFS3DfHUEcwHxBfQjLnUwoWL10/s1600/NAM_221_2012120712_F57_SHRM_925_MB.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="457" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-aqm-Cw5DSgGMJ5P9ZiGjWtfFq9kvrrWksgka4yWDtO3yh7ci_a3ouETdujoggNTltYD07pq8fk5Z0WnCLNeRO0nzADibzziQqrg3Dmh0AC0iNOEwqNFS3DfHUEcwHxBfQjLnUwoWL10/s640/NAM_221_2012120712_F57_SHRM_925_MB.png" width="640" /></a></div>
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So we will probably see a line of strong thunderstorms move across East Texas late in the day in tot eh evening hours with a threat of strong gusty winds and hail. <br />
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After the front moves through MUCH colder air will move into the area. There are now indications as well that an over running precipitation event could unfold on Monday. This is because winds aloft will still be out of the southwest forcing warm air to lift over the colder air at the surface providing clouds and the possibility of precipitation for the morning hours. It still looks as though skies will clear by Monday afternoon but even with the sun breaking out, northwest winds ushering in the coldest air of the season will keep high temperatures in the 40s for most of East Texas, possibly upper 30s across the I-30 corridor if the skies do not clear soon enough. <br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiz8NFkLxHZKMWDEnvwzWleyQdwKM26z7qdhtN6UJMqidnHZThaOCVz-80rIso8TejOmGs1IMipjP7sTBpSz1MW8C-my4ChQpLtLbw8nKAl1O8jNY85hnUqsVDEyLdxF3lLeSdTlRWL3fo/s1600/gfsSP_2_temp_78.gif" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiz8NFkLxHZKMWDEnvwzWleyQdwKM26z7qdhtN6UJMqidnHZThaOCVz-80rIso8TejOmGs1IMipjP7sTBpSz1MW8C-my4ChQpLtLbw8nKAl1O8jNY85hnUqsVDEyLdxF3lLeSdTlRWL3fo/s640/gfsSP_2_temp_78.gif" width="640" /></a></div>
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As for the chance of flurries across the I-30 corridor, the farther west you live, the better chance of seeing this occur, all be it the chance is VERY low! It looks as though most of the precipitation that develops behind the front will evaporate before reaching the ground but across north central Texas, from Dallas , northwest, there will probably be a few flurries Monday morning. If these flurries can hold together we may see a few make there way into the Greenville and possibly Sulphur Springs areas by 9 or 10 AM Monday. This is a very similar set up to a cold front that moved through last December giving a few area of East Texas some flurries, our only winter weather event of the winter season. If this does happen, and right now this looks to be a big if, there will be no travel problems what so ever, just an added chill to get you in the Holiday Spirit. <br />
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<br />Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com1tag:blogger.com,1999:blog-7576661293398923145.post-52523479851224955272012-11-14T07:07:00.000-06:002012-11-14T07:35:34.816-06:00Sleet Last Night?<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitvhZFQymwq5THG2skl_HZkAFOcrmJ-JD8tgSAI6Bmevst_3-cd76x7nXZQFrQS22TTFEQLEC3eAhHO9sQQR7qgRz3yqY9r3gpz3PnWBV2jQtQvfCKS6-vz8uPfYWGO4Dd2NfAU2A4evo/s1600/2012-11-13_23-33-11_515.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitvhZFQymwq5THG2skl_HZkAFOcrmJ-JD8tgSAI6Bmevst_3-cd76x7nXZQFrQS22TTFEQLEC3eAhHO9sQQR7qgRz3yqY9r3gpz3PnWBV2jQtQvfCKS6-vz8uPfYWGO4Dd2NfAU2A4evo/s640/2012-11-13_23-33-11_515.jpg" width="640" /></a></div>
That’s right. A few
areas of East Texas saw a mixture of hail, sleet, and graupel (snow pellets)
late last night and early this morning. So
what happened? Well a fast moving
disturbance brought a lot of high clouds to the area last night and in a couple
of areas these clouds developed into small thundershowers. The image below shows the profile of the
atmosphere early this morning. Here we
can see the cloud base was just over 10,000’ in elevation. When air was lifted from this level it encountered
elevated instability leading to the development of elevated showers and
thundershowers. Since most of the cloud’s
temperature was below freezing, snow and snow pellets were forming instead of
rain. In the strongest updrafts the
graupel, snow pellets, were held aloft allowing water vapor to freeze encasing them in ice until they grew too heavy for the updraft to hold allowing hail,
some up to dime size, to reach the surface.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAEiOLEXQYINayxRupqYUyTuQHPLvdsh_L2pM2_v8Fal6Rx5UvrErhmg48ZpwBARFrspQY-vf5fDmEIaIFyZFP3NpBTlm22mvH2BcotcyCOw101SgVe8a1zjim0ZSutNZrpfMtwjAeTLQ/s1600/last+nights+sleet.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="497" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAEiOLEXQYINayxRupqYUyTuQHPLvdsh_L2pM2_v8Fal6Rx5UvrErhmg48ZpwBARFrspQY-vf5fDmEIaIFyZFP3NpBTlm22mvH2BcotcyCOw101SgVe8a1zjim0ZSutNZrpfMtwjAeTLQ/s640/last+nights+sleet.JPG" width="640" /></a></div>
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Outside the heavy core mainly snow and graupel feel from the
cloud base where above freezing temperatures were encountered below 10,000’. Here the ice crystals began to melt but not
completely as the dry air began the process of evaporation. As the precipitation evaporated it cooled
rapidly allowing for the water droplet to refreeze into sleet.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiMuTvCbdQ9d3zxV19EpMgM4t0vng73eAliv9HGg8vmG8LMzJP87C6kFkZG42rVub4lKykw8iy2k9_UkDD5KXU80NzhAIT3V7Tt0QHw91oxfGEiR_yeiJMUbrYEHWzozRnV-LEmYwJd5ic/s1600/radar.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="558" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiMuTvCbdQ9d3zxV19EpMgM4t0vng73eAliv9HGg8vmG8LMzJP87C6kFkZG42rVub4lKykw8iy2k9_UkDD5KXU80NzhAIT3V7Tt0QHw91oxfGEiR_yeiJMUbrYEHWzozRnV-LEmYwJd5ic/s640/radar.JPG" width="640" /></a></div>
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<span style="font-family: "Calibri","sans-serif"; font-size: 11.0pt; mso-ansi-language: EN-US; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">In the lightest areas of precipitation most of
the precipitation evaporated completely before reaching the ground. The image above shows a radar shot of the
shower across the Lake Fork area. In addition
to the precipitation the elevated instability allowed for the collision of ice crystals
causing a large amount of static charge producing numerous cloud to ground
lightning strike while over the Lake Fork area.</span>Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-58612908261617150642012-11-12T12:05:00.001-06:002014-05-02T21:56:04.303-05:00Henderson Mini Supercell<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK5i_xnUnd-jKTl0_y38IQz6lPqoS9-hVo0ULL9K6_lQmSgaUDrN39kwJdjQln3mk8iNsC7102MSX-k-GmT5snN81anL3lTcB5eXTJK2TQhxdOqU2MrKMj8cDjEHNMUcpfuyyKTrcj8fc/s1600/mini+supercell.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0CYUcL64FUPWvEN2_IcfyGvi9MvxAyHX4iunHNXqiDrm9ILIt6aZur2dVRPD9RzKSIZtzMdDVRTN78Ox5rw8v-j6RfnvucMjBQFBBPXvsDfPTeIbRuBRryKL8oITwmbgDsqNRvesORFY/s1600/378516_4868317195633_2086733162_n.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0CYUcL64FUPWvEN2_IcfyGvi9MvxAyHX4iunHNXqiDrm9ILIt6aZur2dVRPD9RzKSIZtzMdDVRTN78Ox5rw8v-j6RfnvucMjBQFBBPXvsDfPTeIbRuBRryKL8oITwmbgDsqNRvesORFY/s640/378516_4868317195633_2086733162_n.jpg" height="518" width="640" /></a><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK5i_xnUnd-jKTl0_y38IQz6lPqoS9-hVo0ULL9K6_lQmSgaUDrN39kwJdjQln3mk8iNsC7102MSX-k-GmT5snN81anL3lTcB5eXTJK2TQhxdOqU2MrKMj8cDjEHNMUcpfuyyKTrcj8fc/s640/mini+supercell.JPG" height="558" width="640" /><br />
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Sunday afternoon a small but intense thunderstorm developed across Cherokee and Rusk Counties that on radar showed what appeared to be weak but persistent rotation for over one hour as it moved northeast paralleling highway 79 south of Henderson then highway 43 north of Henderson. After looking at the radar data it appears we had a mini supercell develop across East Texas. The storm was never more than 5 miles across and stayed for the most part under 30,000’ in elevation. This is typically not the type of storm that would produce severe weather but in Sunday’s environment, this little storm was able to ingest a lot of low level shear and spin like a top as it moved across the landscape.<br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7vMLXMcCM8qN-PlWUT6HtHauoCbszvhNgBb1FxB8cVR4NG_htHis7kEUVy4r-ecTBGyLw6MryDjDkkvuSezXO5a67VeZ8mGhduMCv2uwxmiUJyUHWGwANX1LYjLy4Y1pgDQ495eiZG8I/s1600/New+Sum+Refl.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7vMLXMcCM8qN-PlWUT6HtHauoCbszvhNgBb1FxB8cVR4NG_htHis7kEUVy4r-ecTBGyLw6MryDjDkkvuSezXO5a67VeZ8mGhduMCv2uwxmiUJyUHWGwANX1LYjLy4Y1pgDQ495eiZG8I/s640/New+Sum+Refl.png" height="558" width="640" /></a><br />
At 3:10PM Sunday afternoon the thunderstorm in question was located near New Summerfield in eastern Cherokee County. At this time the storm’s top was just under 20,000’ in elevation and had a reflectivity core of with a maximum of 54.5dbz under 10,000’. This indicated basically a heavy rain shower, more than likely not even producing any lightning. But at the same time the velocity data did show rotation up to 8000’ in elevation.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi16l2zMqxd8C-mz9FAgAUNO18mDynserJnhfZaL_3y8k1axPguXQ8E9pcLSRfBQGCvcV0t4pWYCBOGeRwJqcLU6XAVcyHgE3syM_9tPGYVDT1A7V_noeXMwP0ho1lzbAVxheprDNhxrzc/s1600/New+Sum+SRV.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi16l2zMqxd8C-mz9FAgAUNO18mDynserJnhfZaL_3y8k1axPguXQ8E9pcLSRfBQGCvcV0t4pWYCBOGeRwJqcLU6XAVcyHgE3syM_9tPGYVDT1A7V_noeXMwP0ho1lzbAVxheprDNhxrzc/s640/New+Sum+SRV.JPG" height="558" width="640" /></a></div>
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Now the rotation was by no means strong but was the beginning of a long lasting rotation that would last in this storm for over 1 hour.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiF6Wxkmq-8t9LMrMpIP-bpXFwmXgMsCs-m7JAyO-_pTkAEXoqksCtp0KcxQcTEZzyo7DMSDAz7CmVs7Sc9Aet3bdxtKsC3c_K2IkQxZrdlilrnQQpM4KspdYncsC30-7CdVHdm8qsOQnY/s1600/Hend+1+SRV.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiF6Wxkmq-8t9LMrMpIP-bpXFwmXgMsCs-m7JAyO-_pTkAEXoqksCtp0KcxQcTEZzyo7DMSDAz7CmVs7Sc9Aet3bdxtKsC3c_K2IkQxZrdlilrnQQpM4KspdYncsC30-7CdVHdm8qsOQnY/s640/Hend+1+SRV.JPG" height="558" width="640" /></a></div>
At 3:44PM the storm in question showed an increase in the inflow velocity a sign that it could be attempting to produce a tornado. Again the rotation was not very strong but at this point it had lasted for over 30 minutes and was showing an increase in strength. At this time the core was 62dbz at 10,000’ but the top of the storm was just barely reaching 30,000’. It was probably producing a few lightning strikes but again it was nothing you would normally consider severe.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3hr1jGSTaqP6cxjrTTrWPbkw3dJ1Wyke7lx17cjCa8zxOOkdR_7dZWuqVVvG5udmGBsQKFm94GexTCSQCmhU7bVydgvfil3FpfNDdSoAfgM3p4lFYjFW8na25j3FSCVRXmLW10vyvD10/s1600/kshv_20121111_2148.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3hr1jGSTaqP6cxjrTTrWPbkw3dJ1Wyke7lx17cjCa8zxOOkdR_7dZWuqVVvG5udmGBsQKFm94GexTCSQCmhU7bVydgvfil3FpfNDdSoAfgM3p4lFYjFW8na25j3FSCVRXmLW10vyvD10/s640/kshv_20121111_2148.JPG" height="523" width="640" /></a></div>
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoGqwLYcful_ZTCVYtez531TsPOh-QwvrNADJ37OXev-vonY5_dgbpnHhsZiUzbFrxpCKuvKwdnKgYEBiqpF_mgZVDTKBj3l9_S4IU6KpnM6vjbCX0aZ3Dw_EsoMfgovOuwe_0DY_WoUQ/s1600/Hend+2+Refl.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoGqwLYcful_ZTCVYtez531TsPOh-QwvrNADJ37OXev-vonY5_dgbpnHhsZiUzbFrxpCKuvKwdnKgYEBiqpF_mgZVDTKBj3l9_S4IU6KpnM6vjbCX0aZ3Dw_EsoMfgovOuwe_0DY_WoUQ/s640/Hend+2+Refl.png" height="558" width="640" /></a>At 3:48PM is when the storm finally peaked showing its mini supercell characteristics. At this time there was rotation, again not very strong, but it was the tightest it has been the entire life span. It is also around this time when a very suspicious photo was sent to us showing what appears to be a well organized mini mesocyclone with a funnel cloud lowering towards the ground. As of this writing it is unknown if the funnel ever touched down to produce a tornado due to no damage reports being submitted.<br />
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As mentioned before, the rotation on radar was not particularly strong and thus really not considered to be a tornado threat. But when you look at the strength of the rotation based on the diameter of the mesocyclone, it is not out of the question that a mini supercellular tornado occurred. A study by the National Weather Service Shreveport in 1997 developed a chart for warning tornadoes during mini supercellular events. A nomogram was developed in 1997 as a guideline for issuing tornado warning based on the rotational velocity (the absolute values of the inbound and outbound velocities divided by two) in a mesocyclone. Based on the velocity data on Sunday the storm in questioned rotational velocity was between 15 and 19, well below the threshold guideline for issuing a tornado warning.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqtPO3bvKIuYGmjd1dx89eBNHdPZZTXGMbOhk-5DGk9LQpdC0b4K6qpvKlkBGHxZFZhzQlxYA8VWUvbbMmTF0Jvc2JzD4gyB_yn7cwHNYOoe5wiP_JLcQ9qvWNWbYk6nIKu0b4uyg5JWY/s1600/mesocyclone+recognition.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqtPO3bvKIuYGmjd1dx89eBNHdPZZTXGMbOhk-5DGk9LQpdC0b4K6qpvKlkBGHxZFZhzQlxYA8VWUvbbMmTF0Jvc2JzD4gyB_yn7cwHNYOoe5wiP_JLcQ9qvWNWbYk6nIKu0b4uyg5JWY/s640/mesocyclone+recognition.JPG" height="587" width="640" /></a></div>
But what the study found in the case of mini supercells was the rotational shear (rotational velocity times 2 divided by the diameter of the mesocyclone) was a better indication of tornado development. When using the rotational shear we come up with a value of 12.3 near the time of the suspicious photo based on a mesocyclone diameter of only 1.59 nautical miles on radar at 3:48PM. This places the rotational shear in the tornado possible area of the rotational shear guideline chart.
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Since the only photo we have has the bottom of the funnel block by trees, and we have had no damage reports from the area, we will never know if a tornado was produced. Hopefully a few more photos will surface that are not obscured by trees to give us a better view of what occurred.
Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-15246651520274286812012-11-05T08:51:00.002-06:002012-11-05T09:34:05.287-06:00Severe Weather This Weekend?<div class="separator" style="clear: both; text-align: center;">
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Long range models are still pointing to a very active weekend weather wise across the central portions of the United States. A deep trough will swing across the Rocky Mountains Saturday and move into the Plains on Sunday. This will cause a strong area of low pressure to develop and swing a cold front through the area. Now there are still some differences on the exact timing of the event, but confidence is rising with the threat of strong to severe storms across the mid section of the nation Saturday and Sunday.<br />
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Right now it appears two areas of low pressure will develop between Friday and Sunday across the high plains ahead of the aforementioned trough. This will cause strong southerly winds to set up all across the Plains States this weekend including East Texas. The second area of low pressure that develops near the Texas Panhandle Sunday will be the one that drags a cold front through the area with the possibility of strong to severe storms Sunday afternoon.<br />
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Right now the limiting factor across the area in preventing severe storms will be the minimal amount of buoyant energy available for thunderstorm growth. Models are paining between 500 and 1000 J/kg of Mean Layer CAPE across the area and we would usually like that number to be greater than 1000 to get strong convection or storms to develop.
<ahref bp.blogspot.com="bp.blogspot.com" e7n3v4vci="e7n3v4vci" gdxeigvapy="gdxeigvapy" http:="http:" imageanchor="1" jg6hujmsb8="jg6hujmsb8" s1600="s1600" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="386" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdpvuNm5MGYiuSq1D42blUDGZww_63QPY8CWst4hisUka8nTYWyu38PVqDz6r_nk0zj5MrtWeiOtn_d0G-aNQZ4y-WlGCVBZtB-B2bUoC94Wv4D-dMFtYvsFOjGBdcre3EDa3kDEhU0Gk/s400/GFS_3_2012110500_F162_CAPE_SURFACE.JPG" width="500" /></ahref><br />
But the surface based Lifted Index, or LIs, are all negative and approach -4, not extremely unstable but are significant when overall CAPE values are low.
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgU4SDQspA53qs9qQURLB6kYAjiPh2UKmjsjcmjt7H-txd0dVuD4vSSgQnDHSsfQwU_gL51AjMXCKBbPOAu1XWX1fGBe0O9SFIZ59fla2OscO8KyGgPnj5GTFoSgAXBWLgLExq1-Px-FiM/s1600/GFS_3_2012110500_F162_LFTX_SURFACE.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="386" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgU4SDQspA53qs9qQURLB6kYAjiPh2UKmjsjcmjt7H-txd0dVuD4vSSgQnDHSsfQwU_gL51AjMXCKBbPOAu1XWX1fGBe0O9SFIZ59fla2OscO8KyGgPnj5GTFoSgAXBWLgLExq1-Px-FiM/s400/GFS_3_2012110500_F162_LFTX_SURFACE.JPG" width="500" /></a><br />
By looking at the profile of the atmosphere we notice the CAPE, energy for thunderstorm growth, is what we call short and fat.
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5_KSWPQyefgaBAHp1R2I-CNZsTMNCdk_UbbMo_HylYhpwmKCyRoFdfc4qk6PowXautZPw01QHXAr5rPWOvDxJQc7ky62FxNuiGYvO1v6J6FqkwMcv3I8Uqmo6H0deODDRVy6_StH_3UU/s1600/GFS_3_2012110500_F162_32.5000N_95.5000W.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="500" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5_KSWPQyefgaBAHp1R2I-CNZsTMNCdk_UbbMo_HylYhpwmKCyRoFdfc4qk6PowXautZPw01QHXAr5rPWOvDxJQc7ky62FxNuiGYvO1v6J6FqkwMcv3I8Uqmo6H0deODDRVy6_StH_3UU/s400/GFS_3_2012110500_F162_32.5000N_95.5000W.png" width="484" /></a><br />
This means even though there is not a substantial amount of CAPE for thunderstorms the updrafts that do develop have the potential to be very strong. This would increase the threat of severe weather including hail and tornadoes.<br />
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Now the wind shear available on Sunday in more than adequate for severe weather across the Plains. The overall bulk shear up to the mid level of the atmosphere is close to 50 knots in most areas and approach 70 knots near the Red River Valley. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjO5sdl5PQY-9OyYTCbIyj_w-DcmTaCGsKkY3si-35_Hx-TDyVraOhSWC0ATLyIaUdWKFZtHXtixGHe8qV70R8FUk1DG46UU54hPxRPrZC5TJwFUeZa8QAdy7XqZI-w6mADJ41TgxVNG60/s1600/GFS_3_2012110500_F162_SHRM_500_MB.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="386" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjO5sdl5PQY-9OyYTCbIyj_w-DcmTaCGsKkY3si-35_Hx-TDyVraOhSWC0ATLyIaUdWKFZtHXtixGHe8qV70R8FUk1DG46UU54hPxRPrZC5TJwFUeZa8QAdy7XqZI-w6mADJ41TgxVNG60/s400/GFS_3_2012110500_F162_SHRM_500_MB.JPG" width="500" /></a><br />
We normally need to see around 40 knots to see supercell development, storms that are capable of producing very large hail and tornadoes. In addition, the 0-1km shear is on the order of 30 knots across most of the area. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3nrZ5_RbxEasJE5CSVbKG_WeSSgdQAj0EMtnsejj0WLeAe9aUPyzr0OIJRK2Wz0uex-rfSF8y0S4rHjveE2HSNYWmG8g_MtaaF9jM7md4ty2KK4QeH7sgshSyjm6TuW3v_69CKH8CWgk/s1600/GFS_3_2012110500_F162_SHRM_925_MB.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="386" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3nrZ5_RbxEasJE5CSVbKG_WeSSgdQAj0EMtnsejj0WLeAe9aUPyzr0OIJRK2Wz0uex-rfSF8y0S4rHjveE2HSNYWmG8g_MtaaF9jM7md4ty2KK4QeH7sgshSyjm6TuW3v_69CKH8CWgk/s400/GFS_3_2012110500_F162_SHRM_925_MB.JPG" width="500" /></a><br />
Levels of 20 knots or greater are usually what we look for in tornado development. Third, the winds just of the surface will be between 50 and 60 knots so any thunderstorm downdraft could easily produce winds over 60 miles per hour. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUm9wIPg4MQpUtxcBgQWynujt3kjl_VFae1h0TOSSDi2RmDUiyzS7ELEmtguPSPsrKJPTXmNHnhxyYep4nMBWRduUHjU7IymWQpY__WM21rBxKmjVqkrJIbT6b70Wbgq1AIYpLK3Rkdb4/s1600/GFS_3_2012110500_F162_WSPD_850_MB.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="386" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUm9wIPg4MQpUtxcBgQWynujt3kjl_VFae1h0TOSSDi2RmDUiyzS7ELEmtguPSPsrKJPTXmNHnhxyYep4nMBWRduUHjU7IymWQpY__WM21rBxKmjVqkrJIbT6b70Wbgq1AIYpLK3Rkdb4/s400/GFS_3_2012110500_F162_WSPD_850_MB.JPG" width="500" /></a><br />
<br />
So the winds energy is more than adequate for high winds and tornadoes if storms can remain scattered.<br />
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The good news, if there is any, is it looks as though this situation will result in a fast moving squall line which will cut down on the tornado threat. The shear vectors will run parallel to the front causing storms to rapidly form into a line. This will increase the threat of widespread wind damage but limit the overall tornado threat. Based on what the models are advertising right now it looks as though storms would begin to develop around midday Sunday. As they initially form there would be a tornado threat due to all the parameters mentioned earlier. But the storms would rapidly form into a squall line before moving into East Texas meaning our main threat would be hail and high winds.<br />
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Again we are still a long way out from this potential event and a lot could and probably will change between now and then. The timing is 24 hours slower than that of my last update and could easily change again. The forecast will be fine tuned as we approach this weekend and all the parts of the puzzle come together. Remember we are entering a period of the year that climatologically produces severe weather. Stay tuned!
Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-82232534886772515752012-11-02T10:23:00.001-05:002012-11-02T10:23:29.972-05:00Severe Weather Possible Next Weekend<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDL3JkuBD9cdbrdY68WR6faokvFpOR6iYz6febFefTk2WokUSsFTdb_kbAGviRDWVFeZ0WZAGtnuU7wL2ZAoSwtwMNhVNsmdiQ5GZq4_nHW4r0e_x0PSjDlTGFyawxikE-uWRzEZeSuW0/s1600/GFS_3_2012110200_F216_WSPD_500_MB.JPG" imageanchor="1" style="margin-left:1em; margin-right:1em"><img border="0" height="426" width="520" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDL3JkuBD9cdbrdY68WR6faokvFpOR6iYz6febFefTk2WokUSsFTdb_kbAGviRDWVFeZ0WZAGtnuU7wL2ZAoSwtwMNhVNsmdiQ5GZq4_nHW4r0e_x0PSjDlTGFyawxikE-uWRzEZeSuW0/s400/GFS_3_2012110200_F216_WSPD_500_MB.JPG" /></a></div>
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This weekend there will be a chance of thunderstorms across
East Texas as a weak cool front moves into the area. As we transition from summer temperatures to
cooler autumn temperatures, the clash of air masses occur more frequently across
our area giving us a second severe weather season that typically peaks around
the second week in November. This
weekend it appears there is a slight chance one or two of the storms could
produce gusty winds and small hail but the overall threat of severe weather
looks minimal at this time.</div>
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That could change though for next weekend. Long range forecast models continue to hint
at a major trough setting up over the Rockies and sending a very strong jet
streak across the Central Plains sometime next weekend. Now this is still a long way out and the position
of the trough and jet streak will probably change but with the models consistently
showing this feature it appears likely a major severe weather event could occur
somewhere across the central part of the United States next weekend. </div>
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At the writing of this article it appears the greatest
threat for severe weather would be form Iowa southwest into North Central
Texas. As the strong jet streak crosses
the Rocky Mountains, an area of low pressure will rapidly develop in Eastern Colorado
and move northeast towards the Great Lakes by Sunday evening. Out ahead of this low pressure, strong
southeasterly winds will set up all across the Plains bringing in moisture from
the Gulf of Mexico. Above these
southeasterly winds, winds will be from the southwest wrapping around the low
pressure as it moves across the area.
This will give the atmosphere plenty of spin needed for severe weather. </div>
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Now in order to get the severe storms we will need enough
instability for thunderstorms to develop.
Right now the models are forecasting just enough instability to get
marginal strong to severe storms. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZNSHD2-BIY4J-QJXczOEMoZRmXb_u4C9PEyWMiQyumaLSurl_-3_RtowzHkKNROZ95JSeAUUHJfsTsoOnRPOAtz4cl-EuyvD2nGtCMdE796PQtZ9jrheaeG3QIFcpb94X8XLpmHbA23s/s1600/gfsSP_0_mlcape_216.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="440" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZNSHD2-BIY4J-QJXczOEMoZRmXb_u4C9PEyWMiQyumaLSurl_-3_RtowzHkKNROZ95JSeAUUHJfsTsoOnRPOAtz4cl-EuyvD2nGtCMdE796PQtZ9jrheaeG3QIFcpb94X8XLpmHbA23s/s1600/gfsSP_0_mlcape_216.JPG" width="520" /></a> But
there are other factors that lead me to believe the storms could be much
stronger. The area across the southern
plains is forecast to be under an area if diffluent winds, or winds that spread
apart aloft. We call this upper air divergence and it
causes the air to rise from the surface.
This will cause the updraft in a thunderstorm to be stronger than just
factoring in the available instability. </div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkDFrvdZf8tuUoh_5kWoIWLKDhyphenhyphenKXavtqyJyY2TzDyFpjYB2R8JIxTVanTvISGpAuHn_LHKKv2pbxdZa1htOdkA6G2cvzpiPSeAO2DryauFYDascsOS9mF97PkqVRFdvH_A4Le_1NN-u0/s1600/gfsSP_250_spd_216.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="440" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkDFrvdZf8tuUoh_5kWoIWLKDhyphenhyphenKXavtqyJyY2TzDyFpjYB2R8JIxTVanTvISGpAuHn_LHKKv2pbxdZa1htOdkA6G2cvzpiPSeAO2DryauFYDascsOS9mF97PkqVRFdvH_A4Le_1NN-u0/s1600/gfsSP_250_spd_216.JPG" width="520" /></a>
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So will this be just a severe thunderstorm event with strong
winds and hail or will this be a tornado outbreak? Well this far out it is too hard to
tell. We need to wait to see how the mesoscale
features develop between now and then.
There will be an awful lot of forcing with this system so it appears
likely a strong line of storms will develop and sweep across the central parts
of the country. However, the low level
shear is forecast right now to be very favorable for tornado development. So if the line of storms can remain broken
there would be an increased threat of tornadoes as it moves through. But with the amount of forcing that is forecast
it seems right now at least the more likely scenario would be an intense squall
line with lots of wind damage and a few isolated tornadoes. Again
it is way too far out to even guess at the exact location of severe weather
next weekend but it does appear likely there will be a threat somewhere across
the central United States from Saturday into Sunday. More details as we get closer to the
event. </div>
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<br /></div>Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-20640777920679656802012-08-27T10:14:00.000-05:002012-08-27T10:14:02.931-05:00Isaac soon to become a hurricaneIsaac will become a hurricane later today as he turns towards the central Gulf Coast. Right now the official forecast takes Isaac into southeastern Louisiana early Wednesday morning as a strong category 1 or minimal category 2 storm. From here Isaac will continue northwest into northern Louisiana near Monroe by Thursday night. The slow movement of Isaac will cause flooding problems along his path as up to 6 to 8 inches of rain could fall. Right now the official track keeps Isaac well enough off to our east where we would see very little in the way of rainfall. It does appear our winds would increase however beginning Wednesday as the difference of pressure between Isaac and a high pressure to our north will cause gusty north northeasterly winds, as high as 30MPH. There would also be a slight chance of a few wrap around showers and thunderstorms, especially Thursday based on the current track. There are still a couple of forecast models that want to bring Isaac right over East Texas. If this were to happen the track of heavy rain would move right across our area with wide spread amounts over 4 inches likely. This scenario appears unlikely at this time but bears watching due to the fact we could use the rain. It appears there will be one way Isaac will affect East Texas even if the path is well off to our east, in the wallet. Anytime a tropical system moves across this area of the Gulf oil prices seem to rise. So if you have the means, be sure to top off the gas tank today as prices will probably begin to rise latter today and tomorrow morning. Hurricane Katrina and Rita took a similar path and caused a huge spike in gas prices. Of course Isaac does not appear to be become near the strength of those storms but it will still be strong enough to cause pressure on the Gulf Coast oil industry. Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-22871023796625082502012-05-17T10:13:00.001-05:002013-01-25T05:15:48.257-06:00East Texas Earthquake HistoryUpdate. May 17th Earthquake was revised to a 4.8!<br />
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At 3:12AM this morning the Earth shook to the magnitude of 4.3 on the Richter Scale as the second earthquake to hit East Texas this month gave a rude awaking to many this morning. Although not unheard of, earthquakes across East Texas are very rare. It has been over 30 years since the last earthquake over 3.0 on the Richter scale hit east Texas which occurred in Jacksonville in November of 1981.
When we think of earthquakes we normally associate California or any other western state where much of the country’s strongest earthquakes have occurred. But earthquakes occur all over the United States and even here in East Texas. Since 1850 there have now been 11 earthquakes reported in East Texas with a magnitude of 3.0 or greater on the Richter Scale. So let’s take a look at when, where, and why these quakes occurred.
The first major earthquake to affect East Texas was probably the great Madrid Fault quake of 1811 in the Boot Heel of Missouri and measured 8.1 on the Richter Scale. This quake caused damage as far away as Boston, MA so I have a hard time believing East Texas did not feel the effects from this quake. However, this first recorded earthquake greater than 3.0 to hit East Texas occurred on January 9th 1891 in Rusk. This quake measured 4.0 on the Richter Scale and reportedly caused significant damage in a few areas. However, there was also a strong tornado that moved across the area that evening and much of the damage reported was probably from weather and not the Earthquake.
The next earthquake to affect East Texas was also the strongest recorded in the area, a 4.7 magnitude quake on March 19th 1957 northeast of Diana. A few windows were broken and much of northeast Texas felt this quake.
For the next seven years the seismic activity across East Texas was quite until April of 1964 when the most active seismic activity hit East Texas. On April 23rd the first quake struck in the southeastern part of Texas near Hemphill and would be the first of eight earthquakes to hit the area over the next few months. In April there were quakes on the 23rd, 24th, 27th, and 28th, with the one on the 28th measuring 4.4 on the Richter Scale. The quakes between the 23rd and 27th all measured between 3.4 and 3.7 on the Richter Scale. There were two smaller quakes on April 30th and May 7th followed by a 4.2 magnitude quake on June 2nd. The last earthquake in East Texas that year occurred on August 16th and was minor.
The next series of earthquakes did not hit East Texas until 1981 when on June 9th a 3.2 magnitude quake hit Center, fairly close to where today’s quake hit. The next quake that year hit on November 6th I Jacksonville registering 3.3 on the Richter Scale.
The last two known earthquakes in East Texas to be a magnitude of 3.0 or higher of course have occurred this month, a 3.9 on the 10th and a 4.3 today. Today’s quake has caused some damage in the Timpson area and even one injury but thankfully nothing too extreme.
When you look at the fault lines across the country you will notice there are literally hundreds that run northwest to southeast across East Texas. That fault lines are classified here as “Class B” faults meaning there is very little seismic activity. It is also interesting to note that studies have suggested that much of the seismic activity along these faults could have been artificially created due to the extraction of oil. I by no means am an expert on this subject but have taking a few geology and geography classes while studying meteorology and find the subject interesting. All the information above in this article came from doing some research this morning on the USGS website. Based on the information I have learned today I would not be surprised to see one or two more quakes before the fault settles down again. Thankfully major damage rarely occurs from earthquakes under 6.0 here in the United States with our stronger building codes and the type of faults across East Texas have yet to produce that strong of an earthquake.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-68878723592154657672012-04-06T14:39:00.011-05:002012-04-07T19:17:26.459-05:004/3/2012 Sulphur Springs, TX TornadoTuesday was a very active weather day across North and East Texas with numerous severe thunderstorms and tornadoes. I went chasing and caught a storm developing over Rains County. By the time we reached Sulphur Springs a tornado warning was issued for strong rotation south of the city. What surprised us was on the back side of the supercell, to the northwest of the radar indicated tornado, we started to notice rapid rotation to our north moving towards Sulphur Springs. The video below shows what we saw.<br /><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='640' height='432' src='https://www.blogger.com/video.g?token=AD6v5dz4dEYoR6JeAqoQ8_kvEsixzTGQfSjZ4NYm8W77hZZWUlGgvbuvxoPjm-4tfghNSRDUnyvOVopUflmU1u0REA' class='b-hbp-video b-uploaded' frameborder='0'></iframe><br />Now the image below shows the approximate area where the tornado in this video was shot. I know I mentioned I did not see any power flashes in the video but after watching the video closely, it appears there were two power flashes. One around 10 seconds in behind the funnel and another at 16 seconds ahead of the funnel. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinOloZJL7yFRY0pzOUVbJ2n-REjLyV_t6Y9kFDzr4TuPambs47H3ASwbvtiBkprcMLHYxfIN4iCRZn5vw8999P3MvqMA5ASPgjyChOnGTTptMsc4VPVnShwLdkbszTgMSItxYfN1QNY4Q/s1600/SS+Tornado+1.png"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 600px; height: 441px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinOloZJL7yFRY0pzOUVbJ2n-REjLyV_t6Y9kFDzr4TuPambs47H3ASwbvtiBkprcMLHYxfIN4iCRZn5vw8999P3MvqMA5ASPgjyChOnGTTptMsc4VPVnShwLdkbszTgMSItxYfN1QNY4Q/s400/SS+Tornado+1.png" border="0" alt=""id="BLOGGER_PHOTO_ID_5728806670043479170" /></a><br />Now the image below is a photo showing the funnel the the east of Sulphur Springs. At this time we did not notice any power flashes and thanks to the tree line it is hard to tell if it is on the ground.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixpeo3aW_DYbHxhbXQl-IfDrZC0SkJigFgoesyw9TSk6ucwOxUV4XF2eAiDNNlFSEzauRUTVxIjrhG9RHI1pmoM58pzaawBICq3Z6HuX2iwGAsi7tp8JlbTWVowNepvayMPPRIX8VGSeo/s1600/IMG_4081.jpg"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 600px; height: 477px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixpeo3aW_DYbHxhbXQl-IfDrZC0SkJigFgoesyw9TSk6ucwOxUV4XF2eAiDNNlFSEzauRUTVxIjrhG9RHI1pmoM58pzaawBICq3Z6HuX2iwGAsi7tp8JlbTWVowNepvayMPPRIX8VGSeo/s400/IMG_4081.jpg" border="0" alt=""id="BLOGGER_PHOTO_ID_5728799905962594146" /></a>The next image shows the velocity data and where the approximate location of the funnel. It looks as though the radar is starting to show a new area of converging rotation forming where the photo was taken.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrznBI2sc8Q_I3VBPVpcNKTglLGJH-L-dWzDAohJHZS0f2EIWRPeJtFCpyAb6zRY_2EKeT-6D4ctBUDfC7TM1L0wcTce41GlGoFC_KS9kvfppHBS7ODcth_VRxfcymQ_ihhkEjNbtbM3U/s1600/SS+Tornado+2.png"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 600px; height: 441px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrznBI2sc8Q_I3VBPVpcNKTglLGJH-L-dWzDAohJHZS0f2EIWRPeJtFCpyAb6zRY_2EKeT-6D4ctBUDfC7TM1L0wcTce41GlGoFC_KS9kvfppHBS7ODcth_VRxfcymQ_ihhkEjNbtbM3U/s400/SS+Tornado+2.png" border="0" alt=""id="BLOGGER_PHOTO_ID_5728806675610212578" /></a> <br />As we continued to follow the storm, rotation was easily seen with every once in a while a thin funnel appearing to touch down. The next image shows the biggest funnel that did touchdown just on the south side of I30 knocking down at least one tree.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSwzVhUZWx491zxq38RR0fnw9XeK_nuAtoxhxoqbEGeJB9l-lfPdhqRncHbfbNeSllOO6IGmVdmfHJKIC23VYbZNiLitNTtHBrwMWddNwb2GD7rGFy6T1JMlEz62S1-KWpw6S88z3wb8U/s1600/IMG_4128.jpg"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 600px; height: 477px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSwzVhUZWx491zxq38RR0fnw9XeK_nuAtoxhxoqbEGeJB9l-lfPdhqRncHbfbNeSllOO6IGmVdmfHJKIC23VYbZNiLitNTtHBrwMWddNwb2GD7rGFy6T1JMlEz62S1-KWpw6S88z3wb8U/s400/IMG_4128.jpg" border="0" alt=""id="BLOGGER_PHOTO_ID_5728426801779943778" /></a>The image below show much stronger converging rotation near the location of the image above.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCQU0LrpMcstqAHFfTSD8xf8OdSmgl3oh4pdHj8DlCm6aBFHfv3l0GqbBYZM3M71D9JI_WxTmVbYOaA4FsrM0Theltn5SKWyNrG2HzxA3RpNsXbfy5QY1hVOk5ohnmoYgyFo3ZAZwtGwA/s1600/SS+Tornado+3.png"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 600px; height: 441px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCQU0LrpMcstqAHFfTSD8xf8OdSmgl3oh4pdHj8DlCm6aBFHfv3l0GqbBYZM3M71D9JI_WxTmVbYOaA4FsrM0Theltn5SKWyNrG2HzxA3RpNsXbfy5QY1hVOk5ohnmoYgyFo3ZAZwtGwA/s400/SS+Tornado+3.png" border="0" alt=""id="BLOGGER_PHOTO_ID_5728806680765793234" /></a>It should be noted that this storm was around 95 miles away from the Ft. Worth Doppler Radar with the lowest tilt hitting the storm just above 11,000' in elevation. So there is no way of knowing what the lowest levels of the storm looked like on radar as the video and photos were shot. Based on what we saw it looks as though Sulphur Springs got pretty lucky as what could have been a tornado going through town either stayed just off the ground or dissipated right before hitting town.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-89633750827177891282012-03-30T09:07:00.005-05:002012-03-30T11:06:46.314-05:00Severe Storms Possible Northwest of Dallas<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9f2GBn24yyM0VASMoDZrz4kfPeNVylCGhuidHTZiUMxyJmlTA2IJ8XH6acC866WEpk9kN79i43FKNn4bngXGR3fmz9sCamSpFmZswBag5vy4VbGs4aWHB8eR17280HS3857N4AFJxXIk/s1600/skew-t.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 245px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9f2GBn24yyM0VASMoDZrz4kfPeNVylCGhuidHTZiUMxyJmlTA2IJ8XH6acC866WEpk9kN79i43FKNn4bngXGR3fmz9sCamSpFmZswBag5vy4VbGs4aWHB8eR17280HS3857N4AFJxXIk/s400/skew-t.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691809000986530" /></a><br />There is a conditional chance of severe storms across parts of North Texas and Southern Oklahoma this afternoon. Forecast sounding near Wichita Falls show showing an extreme amount of instability that could lead to explosive thunderstorm development later this afternoon. The one ingredient lacking to prevent this from being a major severe weather outbreak is forcing to give lift to surface parcels which would in turn cause the storms to develop.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDajl37Wf18DBGSA4r7MXbDVPFxUhpgi5LYJQokw2NwMFUeISV3bTPY1xw1wDHjgWyhqi2yI73GEfbdZ9xzDKFPhadGymMkoUjxAULwgByorqq4O7ByzD3PM6virmGUeUACFwmbJZiMF4/s1600/Severe+Set+Up.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 225px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDajl37Wf18DBGSA4r7MXbDVPFxUhpgi5LYJQokw2NwMFUeISV3bTPY1xw1wDHjgWyhqi2yI73GEfbdZ9xzDKFPhadGymMkoUjxAULwgByorqq4O7ByzD3PM6virmGUeUACFwmbJZiMF4/s400/Severe+Set+Up.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691803112842914" /></a><br />A dryline will be advancing eastward across northwest Texas later this afternoon. This could provide enough forcing to allow one or two isolated storms to develop, especially near the intersection of the thermal axis and moisture axis. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEIuFWof5UvmAg2sSYc78KKxlXUSp2RcmTzFC1Ee0Yht2B3fA09Klh-0FGi9rDNvsRWpWwPHnSrh2uHkJ-vhqD8U6ojT9HRvzNULgZ5eFP2zFJRy_X5MQP4fh46DqFRlxz2kpoR6qWNPQ/s1600/CENTRAL_ETA212_SFC_SLPTHETA-E-CONV_24HR.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 347px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEIuFWof5UvmAg2sSYc78KKxlXUSp2RcmTzFC1Ee0Yht2B3fA09Klh-0FGi9rDNvsRWpWwPHnSrh2uHkJ-vhqD8U6ojT9HRvzNULgZ5eFP2zFJRy_X5MQP4fh46DqFRlxz2kpoR6qWNPQ/s400/CENTRAL_ETA212_SFC_SLPTHETA-E-CONV_24HR.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691716034844290" /></a><br />We can also see that surface moisture is forecast to be converging along the dryline which give added belief in the threat of thunderstorms development.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpwqR_TVGOHTqtLv_dkgVdmr-AAmnFWULo-ORp6V2SQr0pLo85Jr4VsbB7XBuKLFDwN9KOZjhTthdhCBkrIqz2d3clGqDiJg9dzzQBA_GWUwyQyaqWjyYSNjOnQimkBEX2L_sDe28UDSM/s1600/CENTRAL_ETA212_SFC_SLPSBLI_24HR.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 347px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpwqR_TVGOHTqtLv_dkgVdmr-AAmnFWULo-ORp6V2SQr0pLo85Jr4VsbB7XBuKLFDwN9KOZjhTthdhCBkrIqz2d3clGqDiJg9dzzQBA_GWUwyQyaqWjyYSNjOnQimkBEX2L_sDe28UDSM/s400/CENTRAL_ETA212_SFC_SLPSBLI_24HR.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691710067560978" /></a><br />Now all of the area is under extreme instability with LIs running between -11 and -14 across all of north Texas and southern Oklahoma. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1R4re-W8i6Mwrpmaz9789ZbnUGbOeqeNh7mV37lOuRRxuRNvS_Bcoe6uzgE266uEGmcOdTNdtXDN_CLKxY0b9rjAqtpTTTEcMS41DQi-ugLT3GjjutAFrcRxAi5DHTS24vhjN1qf6Pu8/s1600/CENTRAL_ETA212_ATMOS_LSI_24HR.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 347px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1R4re-W8i6Mwrpmaz9789ZbnUGbOeqeNh7mV37lOuRRxuRNvS_Bcoe6uzgE266uEGmcOdTNdtXDN_CLKxY0b9rjAqtpTTTEcMS41DQi-ugLT3GjjutAFrcRxAi5DHTS24vhjN1qf6Pu8/s400/CENTRAL_ETA212_ATMOS_LSI_24HR.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725693289654608594" /></a><br />Over the same area however, there is a small cap. The lid strength index is positive over most of the area, greater than 0°. Usually a lid strength index less than 2° shows there is a chance the cap will break and allow scattered storms to develop. However, with the extreme lack in forcing the cap could very well win out today. There is forecast to be a small upper level disturbance move across this region later this afternoon. This could be just enough lift to take advantage of the extreme instability available.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDoUtHvDKxV0mNFg8AQjP1ATXU1qq9EMfNwyt-ce0H2EvR3rxlkfeotYrZkdjBQaKt5f8XPN9as0_OCSfm0oW-vttbMwsX0MqiRgGXh_5pHkz01riz9iASl6yLNS76hCLsqiYcJuRWwnM/s1600/CENTRAL_ETA212_0-3KM_LAPSE-RATE_21HR.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 347px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDoUtHvDKxV0mNFg8AQjP1ATXU1qq9EMfNwyt-ce0H2EvR3rxlkfeotYrZkdjBQaKt5f8XPN9as0_OCSfm0oW-vttbMwsX0MqiRgGXh_5pHkz01riz9iASl6yLNS76hCLsqiYcJuRWwnM/s400/CENTRAL_ETA212_0-3KM_LAPSE-RATE_21HR.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691696705386914" /></a><br />Many times a weakness in the cap develops near the nose of the low level lapse rate axis. If this occurs today isolated storms could develop very close to Wichita Falls later this afternoon.<br /><br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiJH5cL7K3QQSk90Q7CMs-oEf7KxiNgkLtrVLZQffwqy-rgIJRVAx2D2u7s0-B8yGSZFvxcy7QRdm2rGXQR7pSFvz__8PaPk_rIgjWLWu6tKjBQwtURmMTX4ySZj7ae9qloHOxLSy2bbNs/s1600/CENTRAL_ETA212_0-3KM_CAPE_24HR.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiJH5cL7K3QQSk90Q7CMs-oEf7KxiNgkLtrVLZQffwqy-rgIJRVAx2D2u7s0-B8yGSZFvxcy7QRdm2rGXQR7pSFvz__8PaPk_rIgjWLWu6tKjBQwtURmMTX4ySZj7ae9qloHOxLSy2bbNs/s400/CENTRAL_ETA212_0-3KM_CAPE_24HR.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691692835888978" /></a><br />If storms do develop they will do so in an environment that is not only conducive for very large hail, overall high instability, but they could also produce an isolated tornado. The amount of 0-3km CAPE is approaching 200 J/kg in a few areas which will provide plenty of stretching potential of Strom Relative Helicity which could lead to tornadogenesis.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7lFNAg1qNIdvxpQSqRmZDf1T3-4dNYV8QF99zUFiEuVLxaUGCupN1-LsiLdsk7f17URw28KPQz87ALT67mRdGhTe_SWBQmiApmDQjDMiEKPE0bzNpaRfAl9OcTpfq9TO9aI9O8WB3Iqc/s1600/CENTRAL_ETA212_ATMOS_ESRH_24HR.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7lFNAg1qNIdvxpQSqRmZDf1T3-4dNYV8QF99zUFiEuVLxaUGCupN1-LsiLdsk7f17URw28KPQz87ALT67mRdGhTe_SWBQmiApmDQjDMiEKPE0bzNpaRfAl9OcTpfq9TO9aI9O8WB3Iqc/s400/CENTRAL_ETA212_ATMOS_ESRH_24HR.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5725691705537114162" /></a><br />There does appear to be just enough low level storm relative helicity to introduce a tornado threat as well. So the next few hours will determine what if any storm can develop and whether or not I will be making the four hour drive to see what Mother Nature has to offer.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com1tag:blogger.com,1999:blog-7576661293398923145.post-79944376004124152092012-03-21T10:08:00.004-05:002012-03-21T10:11:58.366-05:00Cold Core Chase Today<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGAgNKsPZZWLAqk70gLXmKJkZTbuxctK-fSE368ada1Rnxc4MA4L7vURuo_gsrzBFzi5A7zfEcN-c_6U20W0rBgN9gQi_ll61Lcrv5ZFmHz9hbz6MYTSUmwHcya6bRfWzOXSVPsC2AYww/s1600/cold+core.jpg"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 265px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGAgNKsPZZWLAqk70gLXmKJkZTbuxctK-fSE368ada1Rnxc4MA4L7vURuo_gsrzBFzi5A7zfEcN-c_6U20W0rBgN9gQi_ll61Lcrv5ZFmHz9hbz6MYTSUmwHcya6bRfWzOXSVPsC2AYww/s400/cold+core.jpg" border="0" alt=""id="BLOGGER_PHOTO_ID_5722367459552544098" /></a><br />All the ingredients are coming together for a cold core set up mini supercell event.The image above shows the surface features in conjunction with the 500mb low pressure. Looks to be a near classic cold core set up. Highlighted area shows where the best combination of parameters come together for supercell development.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-83122875010687409312012-03-20T19:11:00.005-05:002012-03-20T20:08:16.706-05:00Cold Core Set Up Tomorrow?<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0yXwaLhf1s5S8hlSak4oXrEwy_c1inhrLnGVWkxuUHMGXDVrfC3urmuyFbRFpguq0NXFQ2vR6cDLw4ophxz-RLtr71Sr5e4ldt81dto-FYrNsW_BOUuEplm2kQubZx-DL3KFeX2vSioU/s1600/CENTRAL_ETA212_ATMOS_CAPE_36HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0yXwaLhf1s5S8hlSak4oXrEwy_c1inhrLnGVWkxuUHMGXDVrfC3urmuyFbRFpguq0NXFQ2vR6cDLw4ophxz-RLtr71Sr5e4ldt81dto-FYrNsW_BOUuEplm2kQubZx-DL3KFeX2vSioU/s400/CENTRAL_ETA212_ATMOS_CAPE_36HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5722136755553511570" /></a><br />A cut off upper level low pressure could give parts of Texas a surprise severe weather event. High resolution models are trending towards a "Cold Core" set up where low topped mini super cells could develop tomorrow producing small hail, gusty winds, and possibly a tornado or two. Right now the Storm Prediction Center does not have this area under a risk of severe weather. These types of events usually don't materialize until all the mesoscale features come together so we really won't know what will happen until the set up begins to take shape tomorrow afternoon. Looking at the image above, the amount of surface based CAPE is nothing to get excited about. Nowhere do we find CAPE at or above 1000 J/kg.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5Z3XBXkQJgq7fqXMpaldGu_nEj5EUy75k34b6sX9VdsH9-hHwA5PlBMdQTxvtBhdvNMkpCAk-eTu_EkiUkJxxw0gC2y3PeLLHHQi71UmKm2sVTIq5YeSlNE2Cf4E-uVlWMmjgEj7R3Y8/s1600/CENTRAL_ETA212_0-3KM_CAPE_36HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5Z3XBXkQJgq7fqXMpaldGu_nEj5EUy75k34b6sX9VdsH9-hHwA5PlBMdQTxvtBhdvNMkpCAk-eTu_EkiUkJxxw0gC2y3PeLLHHQi71UmKm2sVTIq5YeSlNE2Cf4E-uVlWMmjgEj7R3Y8/s400/CENTRAL_ETA212_0-3KM_CAPE_36HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5722136745441382290" /></a><br />However, the image above here shows 0-3km CAPE approaching 200 J/kg, which is large enough for rapid low level convection needed to generate storms.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzJSZn0UwklhyYM1N2gSntcj05R5mJ7_ZRCfvQCqoivwPssFbJw6iUdu3rFEibfw1VyMM2D1Vda9GzmMt5wbVJNQhhrKJNYl3M4vAnKWcpz1s_84x6t2F2ER1aW_fkAh6N3R6lnzirEkA/s1600/Screen+Shot+2012-03-20+at+7.10.02+PM.png"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 245px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzJSZn0UwklhyYM1N2gSntcj05R5mJ7_ZRCfvQCqoivwPssFbJw6iUdu3rFEibfw1VyMM2D1Vda9GzmMt5wbVJNQhhrKJNYl3M4vAnKWcpz1s_84x6t2F2ER1aW_fkAh6N3R6lnzirEkA/s400/Screen+Shot+2012-03-20+at+7.10.02+PM.png" border="0" alt=""id="BLOGGER_PHOTO_ID_5722142747373130274" /></a><br />When we look at a forecast sounding just south of Forth Worth we can see the majority of the CAPE is located in the lower levels of the atmosphere. In fact, the LIs are positive because all of the energy is located below the 500mb level. In addition, the wind shown on the hodograph turn drastically with height, in the levels where the CAPE is located. This is producing effective bulk shear on the order of 35 to 40 knots. So with enough forcing we could see a few storms develop and in this environment they would likely be low topped super cells. The sounding above shows the maximum parcel level to be around 28,000', not very impressive when you think of severe weather. Even though the CAPE is small, the majority is in areas below freezing thanks too the cold air aloft. So small hail would be likely.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaFM3E0FzSs_QWAZTp-DvMyKmPVYNVeMSx-9wqqBSNfYXeGiHWNRXIodpa_RBp49fPVES4g3fZgkWelvLXWUVNRqWFahv-h7Qy5iiufkDiM2p_U7S6riXW0JyrWmdb541QEQsZ_QlQqR4/s1600/S-PLAINS_NAM218_SFC_SLPTMPDPT_36HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 365px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaFM3E0FzSs_QWAZTp-DvMyKmPVYNVeMSx-9wqqBSNfYXeGiHWNRXIodpa_RBp49fPVES4g3fZgkWelvLXWUVNRqWFahv-h7Qy5iiufkDiM2p_U7S6riXW0JyrWmdb541QEQsZ_QlQqR4/s400/S-PLAINS_NAM218_SFC_SLPTMPDPT_36HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5722142750461000402" /></a><br />The above image is a crude surface drawing showing you where surface features are forecast to be during peak heating in conjunction with the 500mb low. The forcing associated with this low should be enough for scattered storms to develop.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOAGdG5Zu27LbV_e0fGRBy7U2aNoFqfftQYbmr0__krIlqBXH9EW7jjfyQeuj1dSQqCO4m-ZKsY7txqH_iWE_2vKvuf_LiNylPQs01zxkR1C0ZpDZyYYCyyRTZ3j-yKC1JgaoFhNFdSRI/s1600/S-PLAINS_WRF_1000-500_SLPTHKPRP_36HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 302px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOAGdG5Zu27LbV_e0fGRBy7U2aNoFqfftQYbmr0__krIlqBXH9EW7jjfyQeuj1dSQqCO4m-ZKsY7txqH_iWE_2vKvuf_LiNylPQs01zxkR1C0ZpDZyYYCyyRTZ3j-yKC1JgaoFhNFdSRI/s400/S-PLAINS_WRF_1000-500_SLPTHKPRP_36HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5722143395926549074" /></a><br />In the final image above, the high resolution WRF model is breaking out an arc of scattered cells around the forcing associated with the 500mb low. If this does occur in the environment the forecast sounding predicts, these will more than likely be low topped super cells. The tornado threat looks very low thanks to the fairly high cloud base the NAM is predicting. However, the LCL is as low as 915m on the sounding above which could lead to an isolated tornado if the surface environment sets up the way it is forecast by the NAM. Right now I look for the SPC to have a 5% chance of hail tomorrow across North Texas with no tornado threat during their first outlook. Once the surface features tomorrow afternoon are known, a 2% tornado risk may be introduced.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com1tag:blogger.com,1999:blog-7576661293398923145.post-41376259118877688342012-03-20T08:38:00.006-05:002012-03-20T08:50:29.029-05:00So What Happened With Yesterday’s Tornado Threat?Yesterday much of East Texas was under a moderate risk of severe weather including a 10% chance of tornadoes, which is an elevated risk for tornadoes. We had strong southeasterly winds at the surface with strong westerly winds aloft giving East Texas a significant amount of shear and spin to the atmosphere. All that was missing was the energy to lift the air for convective initiation. If you remember from yesterday’s forecast sounding models were painting a pretty scary picture across East Texas. Temperatures were forecast to reach close to 80 degrees with dewpoints in the middle 60s. This provided a forecast Surface CAPE over 2500 J/kg. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6f9zM88ts6jMvgsd1H-hP9VGt3NCaqVPzTZoSs5zJ4ywuETzID6cLc8MdaqiYmOD9Fp6DCgJCgsekqP0tglz8I_988JJ4ClsN0aDditTB8Cv4qCqesT9bJXWcQjTEZxTbU7B8oB1Mg6k/s1600/New+Image+6.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 383px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6f9zM88ts6jMvgsd1H-hP9VGt3NCaqVPzTZoSs5zJ4ywuETzID6cLc8MdaqiYmOD9Fp6DCgJCgsekqP0tglz8I_988JJ4ClsN0aDditTB8Cv4qCqesT9bJXWcQjTEZxTbU7B8oB1Mg6k/s400/New+Image+6.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721973356634042770" /></a><br />With a little extra sunshine, drier air mixed down to the surface producing dewpoint about 5 degrees cooler than forecast. As you can see if we modify the forecast sounding with the actual dewpoints, the CAPE nearly disappears and the lower levels of the profile experience Convective Inhibition, or a cap.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuzGzNkw024MAqlYKQ1ZoT8pPxCPo5JO0sgrhZc87kbVmFgnVnRCZYL2WQLJnsB-XhKxMWDRHOCMBfQigpAgEGC-sJ4UA_3t4UQoFDWVNuT4dEM5V8QS7snX1Crv2xIhLWw9dPMNHTV94/s1600/New+Image+6+new.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 383px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuzGzNkw024MAqlYKQ1ZoT8pPxCPo5JO0sgrhZc87kbVmFgnVnRCZYL2WQLJnsB-XhKxMWDRHOCMBfQigpAgEGC-sJ4UA_3t4UQoFDWVNuT4dEM5V8QS7snX1Crv2xIhLWw9dPMNHTV94/s400/New+Image+6+new.JPG" bSo with the new cap in place any updraft that tried to originate was quickly forced down to the surface keeping thunderstorms from developing. Many times when everything points to a significant severe weather event, an unforeseen event puts the breaks on severe thunderstorm development.order="0" alt=""id="BLOGGER_PHOTO_ID_5721973425577245810" /></a>So with the new cap in place any updraft that tried to originate was quickly forced down to the surface keeping thunderstorms from developing. Many times when everything points to a significant severe weather event, an unforeseen event puts the brakes on severe thunderstorm development.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-8112526606374730442012-03-19T08:57:00.006-05:002012-03-19T09:36:23.174-05:00A Moderate Risk for Severe Storms Including Tornadoes Today<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirKQ1V3txHpd6EPPpzQyQjobZvfuQdxBAqBmwsINvm7OYJ05ZD5_U2VxNRawPcrXYczPH1jxaNujy3MxbbQYUQgS2KSCvtnHXfPa5VfS_p24Rehi6-f9R25TZNq3TEgWFOJlkXV9VsFlw/s1600/day1otlk_1300.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 333px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirKQ1V3txHpd6EPPpzQyQjobZvfuQdxBAqBmwsINvm7OYJ05ZD5_U2VxNRawPcrXYczPH1jxaNujy3MxbbQYUQgS2KSCvtnHXfPa5VfS_p24Rehi6-f9R25TZNq3TEgWFOJlkXV9VsFlw/s400/day1otlk_1300.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607942960500066" /></a><br />There is a moderate risk of severe thunderstorms across East Texas today including the threat of tornadoes. A very warm and moist air mass has set up across East Texas thanks to 7 days of a southeasterly flow off the Gulf of Mexico. Dew point temperatures are forecast to peak in the lower 70s ahead of a developing line of thunderstorms. The image below shows most of East Texas covered in yellow meaning dewpoints will be at least 65 degrees providing plenty of energy for thunderstorm development. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJC6m8R1s8_ZCUkbppYk5j3VWRqZE86j_gTTGbDu5BNSNLc0K2-l0T4RUzdCcN5VOw_y99K6VPbQFgviUQE9lXXxoKlDZglk3XRuwRV-1XHbsfwB57rgParPPyzasnHeboth7vTP249gA/s1600/New+Image+4.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 372px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJC6m8R1s8_ZCUkbppYk5j3VWRqZE86j_gTTGbDu5BNSNLc0K2-l0T4RUzdCcN5VOw_y99K6VPbQFgviUQE9lXXxoKlDZglk3XRuwRV-1XHbsfwB57rgParPPyzasnHeboth7vTP249gA/s400/New+Image+4.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607311914651666" /></a><br />The latest High Resolution Rapid Refresh model breaks out a broken line of thunderstorms later this afternoon heading towards East Texas. This will be the first round of at least three lines of storms that develop.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL5znfO-ndC18LI-kXEGkVYRkp2f7ZARggh-aI56IV9kkqvbC11gjfQZ8M8r0l8KR_4vy3kqEY3HOIG2BjMDT0EpxwTDlIcJPnT9BQLAaNLWET2jgAD-mbfETMl4ZLC8EkVSVv6mRMHIc/s1600/New+Image+3.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 369px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL5znfO-ndC18LI-kXEGkVYRkp2f7ZARggh-aI56IV9kkqvbC11gjfQZ8M8r0l8KR_4vy3kqEY3HOIG2BjMDT0EpxwTDlIcJPnT9BQLAaNLWET2jgAD-mbfETMl4ZLC8EkVSVv6mRMHIc/s400/New+Image+3.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607307587686050" /></a><br />The 0-6KM shear available across East Texas is more than enough for the storms that develop to become supercellular. Shear values will be approaching 50 to 60 knots across the area allowing mid level rotation to form with any storm that develops.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgc-P9xIQLPMQObAVhELIeFUdlz8LaUVkg6W5E1B83UUMuoRnVaCqRTmMY9YdAzXln8dABWtvpl7SkVQrDzb51CKkasgmZXlJ2rXhOn8x6vgnbNSLf5fGoCkLkXeIrEtMQ5nI8b9AeI34E/s1600/New+Image+2.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 371px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgc-P9xIQLPMQObAVhELIeFUdlz8LaUVkg6W5E1B83UUMuoRnVaCqRTmMY9YdAzXln8dABWtvpl7SkVQrDzb51CKkasgmZXlJ2rXhOn8x6vgnbNSLf5fGoCkLkXeIrEtMQ5nI8b9AeI34E/s400/New+Image+2.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607304601991106" /></a><br /> As these rotating thunderstorms move into East Texas they will be encountering low level helicity levels that are conducive for low level rotation which could lead to tornadogenesis. The image below shows areas of light green and yellow out ahead of the storms show low level helicity between 200 and 300 m^2/s^2. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsxx1tNDqJWcR8BPk5uwrCC2-OF3xjRtOFJ2a5io2N1X-ff8Q-azcyeoGEJiW-MxZrmVeshHZ3I47U6fd6A0u4LxBvRiDfoQigwP-w5MM7tgFNNpqGwLgML2aHb3-vcHFdFQOmrJY3pAc/s1600/New+Image.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 370px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsxx1tNDqJWcR8BPk5uwrCC2-OF3xjRtOFJ2a5io2N1X-ff8Q-azcyeoGEJiW-MxZrmVeshHZ3I47U6fd6A0u4LxBvRiDfoQigwP-w5MM7tgFNNpqGwLgML2aHb3-vcHFdFQOmrJY3pAc/s400/New+Image.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607302327850754" /></a><br />The environment also shows large hail to be very possible across East Texas this afternoon and evening. The forecast soundings for both Forth Worth and Shreveport show large amounts of CAPE in the hail growth region. With the high shear levels, ice particles we be in the hail growth region longer making golfball to baseball size hail possible with the strongest storms. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzo_irjL2eBXbG3Zfyj0VyDA3oS2QQ19pFb2hNrn5zPaHctBUxqHNTxr1ohLENMdQtDpb-hHKeTcEsyHFeJGrr-dxWZIjKfDBjIeAa155lCr5Fa0oM3W6jO4WUea99QOdUrd6siIdkwSw/s1600/New++Image+5.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 383px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzo_irjL2eBXbG3Zfyj0VyDA3oS2QQ19pFb2hNrn5zPaHctBUxqHNTxr1ohLENMdQtDpb-hHKeTcEsyHFeJGrr-dxWZIjKfDBjIeAa155lCr5Fa0oM3W6jO4WUea99QOdUrd6siIdkwSw/s400/New++Image+5.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607297810920018" /></a><br />One thing you will notice is the winds are more favorable for tornadoes the farther east you go. The good news is the farther east the storms move, the less forcing they will encounter so they may begin to weaken just a bit. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6_k55saCTRlFfx4GLV6Vbw_5jSZDCDcn10-TlewMe5vIe6hX_SdIohfvDwKipUDjCqNGYYN1uvOSdhdZJg7XkRkDCahaHRN3ZKTb4FA94ZAOemCrvj7oQHtxgA30K0ECk-y62yp7D6Ak/s1600/New+Image+6.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 383px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6_k55saCTRlFfx4GLV6Vbw_5jSZDCDcn10-TlewMe5vIe6hX_SdIohfvDwKipUDjCqNGYYN1uvOSdhdZJg7XkRkDCahaHRN3ZKTb4FA94ZAOemCrvj7oQHtxgA30K0ECk-y62yp7D6Ak/s400/New+Image+6.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5721607358305361298" /></a> It does appear after the first round of storms moves through, more storms will develop throughout the night and into tomorrow morning. Before the rain ends Wednesday much of East Texas will receive between 3 and 6 inches of rain with a few areas picking up over 8 inches of rain.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com1tag:blogger.com,1999:blog-7576661293398923145.post-70354506976054340542012-03-08T09:51:00.003-06:002012-03-08T09:52:50.637-06:00Strong Storms and Heavy Rain Likely Today<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhXyWpOw933OPEHfq4JDmzkaQmqFpSKnuOwne8k_BXQlEbKmhTLDLQfQBfuzg2EIdREul5aP4nMd6flMmh9jNlNu4hN4QyuQmZwrmjOlpzfzrZSrm3T9kw2zBGlRSv_zaaCNZHUEeYUEuM/s1600/weekend+rain.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 300px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhXyWpOw933OPEHfq4JDmzkaQmqFpSKnuOwne8k_BXQlEbKmhTLDLQfQBfuzg2EIdREul5aP4nMd6flMmh9jNlNu4hN4QyuQmZwrmjOlpzfzrZSrm3T9kw2zBGlRSv_zaaCNZHUEeYUEuM/s400/weekend+rain.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5717554428786425474" /></a><br />A strong cold front was moving south across the Southern Plains this morning and will be moving into our northern counties later this afternoon pushing all the way through East Texas by Friday morning. Out ahead of this front showers and an occasional thundershower will develop this morning into the early afternoon hours. <br />By late afternoon as the front moves into the I-20 corridor during peak afternoon heating, there will be a chance of a severe storm or two. Right now the overall severe threat does not appear that great but the strongest storms will be capable of producing wind gusts to 60 mph and hail up to the size of quarters. The tornado threat appears to be fairly low today as most of the stronger storms will develop right along the cold front which will make the storms slightly elevated, thus not allowing them to ingest the surface air needed to produce tornadoes. However, if an isolated strong storm or two develops out ahead of the cold front, a tornado threat could develop briefly this afternoon.<br />Once the front moves through the threat of rain and thunderstorms will not end any time soon. An area of low pressure in the mid and upper levels of the atmosphere will keep southerly winds just off the surface forcing warm moist air to move over much cooler air at the surface as highs will struggle to reach the middle 50s. This will provide the perfect situation for an over running precipitation event starting tonight and lasting through most of Friday. Forecasts show an average of 1 to 3 inches of rain occurring with this event before ending late Friday.<br />Another disturbance will move to our north on Saturday providing the same type of over running precipitation event once again. This event will last through Saturday evening before a warm front is pushed north across the area Sunday morning. This will not shut of the rain either. An area of low pressure at the surface will surge north from the Gulf Coast into the Ozarks on Sunday. This will give East Texas another chance of showers and storms. Before all is said and done early Monday morning, much of East Texas could see at least 5 inches of rain with some local areas receiving up to 8 inches.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com1tag:blogger.com,1999:blog-7576661293398923145.post-89623433136189424832012-02-28T08:47:00.002-06:002012-02-28T09:15:02.710-06:00Severe Threat Very Small TodayYesterday I showed you the conditions coming together for a conditional threat of severe weather across East Texas. Today after looking at the latest data it appears the EML (elevated mixed layer) or cap will be to strong across East Texas for thunderstorm development. All the other conditions I mentioned in yesterday’s write up are still coming together so if A storm were able to develop, it would likely become severe rapidly producing large hail, gusty winds, and tornadoes. But that just doesn’t appear likely.<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhv-oEAqaG3ZUuEo5GKHljVUDP17wXbBs4_Zh30ZlNTklMTwPIuL8e53w4omg953RxWtNN4jIk3mCfIsIe7aHSk2dXIJFtZAYPlSa0p_ahddG2ufyCe5-kH3rZ7JMVSy2p4c3Xng_5EWzs/s1600/Skew-T.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 254px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhv-oEAqaG3ZUuEo5GKHljVUDP17wXbBs4_Zh30ZlNTklMTwPIuL8e53w4omg953RxWtNN4jIk3mCfIsIe7aHSk2dXIJFtZAYPlSa0p_ahddG2ufyCe5-kH3rZ7JMVSy2p4c3Xng_5EWzs/s400/Skew-T.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5714198525105509282" /></a>When we take a look at the forecast sounding for this afternoon we notice a very large area of CIN (convective inhibition). This is a large amount of negative energy (blue shaded region), or sinking air, that would not allow upward motion of air parcels allowing for thunderstorm growth. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3-r5EhnItFf6a_Saowqc9tvzLOGt7nOWE7e4lEIowsMF4ZtX08wfuCWwza8ha9jy5aD43xX25R0BWGkA8EWS8nCWn0noygur2whdtk-R3QkUbweAMcY_ldORL_7en_QVUllE8RLZpMXg/s1600/Skew-T+Mod.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 254px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3-r5EhnItFf6a_Saowqc9tvzLOGt7nOWE7e4lEIowsMF4ZtX08wfuCWwza8ha9jy5aD43xX25R0BWGkA8EWS8nCWn0noygur2whdtk-R3QkUbweAMcY_ldORL_7en_QVUllE8RLZpMXg/s400/Skew-T+Mod.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5714198515474944578" /></a>Now yesterday I mentioned this as well and was concerned what would happen if we saw a few more breaks in the clouds allowing for warmer afternoon temperatures, like we saw yesterday. Well when the forecast sounding is modified for a surface temperature around 76°F it looks a lot more conducive for thunderstorm development. Notice the area of CIN (blue shaded area) is much smaller than the actual forecast. Also the amount of CAPE, or buoyant energy (yellow shaded area), is much greater. This could allow for explosive thunderstorm development if we see surface temperatures warm into the upper 70s this afternoon.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEoeso1c_fwwjmIZ_QBQky-Hnc2kigXb-TurIyqtfQ-M9c5WNY27UwoQnRfW8oYyNQgu3JINnZ1mChVH2lEDYU1mVzw0EOeYx46x9xwZoRabxNWQLibFUOa3JjQfBeulI8gK7_KOjSd5U/s1600/DRT.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 287px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEoeso1c_fwwjmIZ_QBQky-Hnc2kigXb-TurIyqtfQ-M9c5WNY27UwoQnRfW8oYyNQgu3JINnZ1mChVH2lEDYU1mVzw0EOeYx46x9xwZoRabxNWQLibFUOa3JjQfBeulI8gK7_KOjSd5U/s400/DRT.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5714198510344458658" /></a>Again in theory severe weather is possible this afternoon based on forecast soundings. That is why looking at the actual sounding is so important. So this morning I wanted to see what was happening downstream from East Texas because this air mass will be over us later today. By looking at the actual sounding from Del Rio area we can see the EML is very strong with a temperature of 15°C at 800mb. We you modify the forecast sounding for that 800mb temperatures the convective temperature, or the temperatures at where air rises freely allowing thunderstorms to develop, is well into the 80s which we will not see today. So based on all the information I see right now East Texas appears to be safe from severe weather this afternoon. We will see a line of showers and storms move in overnight but by that time the dynamics for severe weather and tornadoes will be off to our north and east. But if the temperatures are able to reach the upper 70s to near 80, there could be an isolated severe storm late today but right now that does not seem very likely at all.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-53014940306964969902012-02-27T09:37:00.008-06:002012-02-27T10:54:10.856-06:00Conditional Severe Weather Threat Tuesday<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi34s72pu3gc1F_7Lu8vceqzYkMsYs7DU-pc4EaP1tqhBOKRuTpcIt_QKpoqTXPfKmZetYzihJyo9ouw-DOfa3513ReAgRrc5tShPcuujK2CZ_ATfdL6B0_MoJYyoRlvthXU4wId5Sf8S0/s1600/CENTRAL_ETA212_SFC_SLPSBLI_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 347px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi34s72pu3gc1F_7Lu8vceqzYkMsYs7DU-pc4EaP1tqhBOKRuTpcIt_QKpoqTXPfKmZetYzihJyo9ouw-DOfa3513ReAgRrc5tShPcuujK2CZ_ATfdL6B0_MoJYyoRlvthXU4wId5Sf8S0/s400/CENTRAL_ETA212_SFC_SLPSBLI_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840408397944882" /></a><br />A strong area of low pressure at the surface will develop in western Kansas tomorrow afternoon and race off to the northeast into south central Nebraska during the evening hours. As this system develops strong southerly winds will bring warm moist air into East Texas which could set the stage for strong to severe thunderstorms late Tuesday into Wednesday morning. Instability is forecast to be marginal for severe storms but with a little more sunshine than predicted, things could get much worse.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeHvOlEN8L1u4Q7FNTHbGohewP3LsoaKgrrOHGs0jiZstTcD6hKoBQ1bDTvIbD4iJpIuzoEJQm-_pClb25w2O1G9VqA9wYr_b3hzECD8PP_DQ1tKSv5c7Dli4ka0loV6JShl2baHM_k64/s1600/CENTRAL_ETA212_ML_CAPE_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeHvOlEN8L1u4Q7FNTHbGohewP3LsoaKgrrOHGs0jiZstTcD6hKoBQ1bDTvIbD4iJpIuzoEJQm-_pClb25w2O1G9VqA9wYr_b3hzECD8PP_DQ1tKSv5c7Dli4ka0loV6JShl2baHM_k64/s400/CENTRAL_ETA212_ML_CAPE_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840398437292002" /></a><br />Right now forecast models are indicating Mean Layer CAPE values to be at or slightly above 1000 J/kg. This is basically the beginning threshold for the possibility of severe thunderstorms. This will provide enough energy to accelerate surface air upward causing clouds, and eventually thunderstorms to develop. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoLNSPEp6Ts0k-nD7n_tokP16QwSwZuqiWIjjYGmh3DlP5hYXqpPYymmsFPCOKedH98pInzQnEzxg84iFz7_3GSG1uaxs345DZGfH8cpRNtYnbGpa8TI-00zDGRlVH42sW1SaAlfCkj0g/s1600/CENTRAL_ETA212_ATMOS_ESHR_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoLNSPEp6Ts0k-nD7n_tokP16QwSwZuqiWIjjYGmh3DlP5hYXqpPYymmsFPCOKedH98pInzQnEzxg84iFz7_3GSG1uaxs345DZGfH8cpRNtYnbGpa8TI-00zDGRlVH42sW1SaAlfCkj0g/s400/CENTRAL_ETA212_ATMOS_ESHR_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840389531300642" /></a><br />Now that we see there is just enough energy to produce severe convection we need to see what is happening to the air as it rises to predict what kind of storm will develop. For supercell thunderstorms to develop we usually like to see effective shear, or the amount of shear the entire updraft will encounter, to be greater than 40 knots. Tomorrow afternoon much of East Texas is seeing effective shear greater than 70 knots. Now usually this would set off an alarm in my head but with the MLCAPE only being around 1000 J/kg, many of the updrafts will actually be sheared apart before a storm can develop. More on this later. So if a storm develops it would become a supercell.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbXoNcF3Rzg-CKHvtMJK3mb0nmih9XNPzIXdApCCSw3Fp22kC682HdF1ZWR-3i6Xc4k0k3pXxftAlzne_clQmCHwPUx1HEgz3TleJqnaLmrhQxuiRu2bWjKuM_KU6YdJmnRPeoFsL7yno/s1600/CENTRAL_ETA212_ATMOS_ESRH_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbXoNcF3Rzg-CKHvtMJK3mb0nmih9XNPzIXdApCCSw3Fp22kC682HdF1ZWR-3i6Xc4k0k3pXxftAlzne_clQmCHwPUx1HEgz3TleJqnaLmrhQxuiRu2bWjKuM_KU6YdJmnRPeoFsL7yno/s400/CENTRAL_ETA212_ATMOS_ESRH_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840391619102626" /></a><br />The amount of storm relative helicity or the amount of spin available for the lower levels of the storm to ingest, are also showing high enough levels to produce low level storm rotation. We usually look for values at or higher than 200 and much of East Texas tomorrow afternoon is above 300. So if a storm can develops it would easily be able to produce low level rotation which could lead to tornadogenesis.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTl4jvs5UfF5FbfPpiLJS5o3ROkvp1xZfkniX5czBV5dJacpU7EPxOSgafCflajGGcGOMOWfIUxrCSbdQnVq2oPx2Vt3luzBnIzpvpXNRxSJlqQSE7udjjwycrbRDKhJ1n9QmNafBSOPQ/s1600/CENTRAL_ETA212_ANVIL-LEVEL_SR-WIND_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTl4jvs5UfF5FbfPpiLJS5o3ROkvp1xZfkniX5czBV5dJacpU7EPxOSgafCflajGGcGOMOWfIUxrCSbdQnVq2oPx2Vt3luzBnIzpvpXNRxSJlqQSE7udjjwycrbRDKhJ1n9QmNafBSOPQ/s400/CENTRAL_ETA212_ANVIL-LEVEL_SR-WIND_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840104548939458" /></a><br />Now that we now the storms that develop tomorrow should be supercellular, what type of supercell is likely to develop? For this we need to take a look at the storm relative anvil winds to give us an idea of the titling available to the main updraft. High precipitation supercells develop in areas with numerous storms, which won’t happen tomorrow, or storm relative anvil winds less than 40 knots. Classic super cells tend to form when the storm relative anvil winds are between 40 and 60 knots with anything higher than 60 knots leading to low precipitation supercells. The storm relative anvil winds tomorrow are between 50 and 70 knots, so classic and low precipitation supercells would more than likely be the storm mode. This means the rain cooled down draft will be well displaced from the updraft helping to keep the storm strong and making it live longer.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhptzgeXB4_bsPaATEx-RYhqRk2nuhU_LuEybvSIxxfLa3sCXRaopsE43ol-HOHxF0CMK1JR49Fq2N3RwrlAKUR_glSn3W8jUXrH2Sqb5S6906uZIU5pm2XAn_cqn4VKFXsc3lg_Lcbfvo/s1600/CENTRAL_ETA212_1KM_SR-WIND_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhptzgeXB4_bsPaATEx-RYhqRk2nuhU_LuEybvSIxxfLa3sCXRaopsE43ol-HOHxF0CMK1JR49Fq2N3RwrlAKUR_glSn3W8jUXrH2Sqb5S6906uZIU5pm2XAn_cqn4VKFXsc3lg_Lcbfvo/s400/CENTRAL_ETA212_1KM_SR-WIND_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840100373713986" /></a><br />So now that we know what our storm mode should be, it is time to see if the parameters are there to allow the low level rotation that should occur with any storm that develops could turn into a tornado. One area we look at is the storm’s inflow. Inflow of 20 knots or greater is usually a good indicator that tornadoes could develop. Tomorrow most of East Texas will see storm relative inflow greater than 25 knots. We also need to see the directional shear meaning winds changing direction as you move up through the atmosphere. Now in tomorrow’s set up the wind are fairly unidirectional, or blowing from the same direction, as you move up through the atmosphere. Normally this would limit the tornado threat. However when you factor in the storms motion, the low level storm relative winds become southeasterly setting the stage for directional shear.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJz8XIHJTTvwe6TJQLFu72FIjhYFKmR3DB4WOnCr3a5WKTJuoKzaoBB7G0dNaEdZ3ddaIzXfcn8q_EGY9bCFDSw-djUOklbOVNWiQ7PC9zSGRdOKj2kbdWFsNXqItQxf38L9_AC1skXXk/s1600/CENTRAL_ETA212_0-3KM_CAPE_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJz8XIHJTTvwe6TJQLFu72FIjhYFKmR3DB4WOnCr3a5WKTJuoKzaoBB7G0dNaEdZ3ddaIzXfcn8q_EGY9bCFDSw-djUOklbOVNWiQ7PC9zSGRdOKj2kbdWFsNXqItQxf38L9_AC1skXXk/s400/CENTRAL_ETA212_0-3KM_CAPE_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840095679148290" /></a><br />Another factor we look for in tornado development is the CAPE in the lowest level of the atmosphere. This is the amount of energy to force air to rise. The stronger the lowest level CAPE is the better chance there is any surface vorticity can be stretched into the storm’s low level rotation which in turn can lead to the development of a tornado. Tomorrow we are seeing 0-3KM CAPE values approaching 80J/kg over much of East Texas leading to a VGP, vorticity generating potential of greater than 0.40. VGP values greater than 0.30 can lead to tornado development.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6gsBp2YMTCEQoF_0s7B2_rs37RYEtvR_Xo0-06Cs9TXn-X9jZDZTF_4R8mzOQ3ReIC7sI0Yyp6MuoYvMXlSIDt6XS03ZDid9MbuyXvYgPVklrwp116iOe0UzLVQJgqOIGr1MBzc8gikI/s1600/CENTRAL_ETA212_0-1KM_VGP_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6gsBp2YMTCEQoF_0s7B2_rs37RYEtvR_Xo0-06Cs9TXn-X9jZDZTF_4R8mzOQ3ReIC7sI0Yyp6MuoYvMXlSIDt6XS03ZDid9MbuyXvYgPVklrwp116iOe0UzLVQJgqOIGr1MBzc8gikI/s400/CENTRAL_ETA212_0-1KM_VGP_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840094333305730" /></a><br />Finally we like to see what the lowest level shear values will be to determine tornado development. Usually 0-1km shear levels above 20 knots are favorable for tornado development. Tomorrow much of East Texas is seeing that level between 25 and 35 knots.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtFJql6zVQ5eS8CDqFpm4CNPJYE5qBHahuPpHM0jBtvrlJFVFFMxroDqu5W1Dza-0_BVttfL8z8yjOZnk_dyjtkQVm77DzQDOhukVgbtaToDtz1nb3gklq8Nqx0083Qw0YEiQ03CBliOw/s1600/CENTRAL_ETA212_0-1KM_SHEAR-VECTOR_48HR.gif"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 346px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtFJql6zVQ5eS8CDqFpm4CNPJYE5qBHahuPpHM0jBtvrlJFVFFMxroDqu5W1Dza-0_BVttfL8z8yjOZnk_dyjtkQVm77DzQDOhukVgbtaToDtz1nb3gklq8Nqx0083Qw0YEiQ03CBliOw/s400/CENTRAL_ETA212_0-1KM_SHEAR-VECTOR_48HR.gif" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840086105863106" /></a><br /> So all the factors are coming together for what seems to be a fairly active severe weather day. So why is there not a higher risk of severe weather tomorrow and the threat right now is only figured to be conditional? Remember earlier I mentioned many times when the bulk shear is as high as it will be tomorrow the storm’s updraft can be sheared apart. With the lack of forcing and no surface convergence, storms will develop from rising air caused by differential heating across the area. The image below is a Skew-T forecast for tomorrow evening at Tyler, TX. I have pointed out a very strong cap located around 700mb, or about 9,000’ in the atmosphere. This will put a lid on all thunderstorm development which is why there is not a greater risk of severe weather. If the storm system would move a little farther south then the forcing, or lift across East Texas would be greater allowing for a few thunderstorms to develop. What we really need to watch out for tomorrow is any additional clearing which could happen tomorrow afternoon. With the surface winds being out of the south southwest tomorrow, slightly drier low level winds could remove the lower cloud deck. This would allow temperatures to approach the convective temperature, which is around 77°F tomorrow afternoon. If this does happen then isolated thunderstorms will develop, like we see in the summer. But these storms will develop in an atmosphere that is very likely to develop not only severe storms, but tornadoes as well. <br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt7mMEXVDWufUFRMhpzyXByTboIbm02CSNaT7w__sye4AqngVJ6pIooyf4o6TnQY791ypl-Zmr3ZbJymbuzXANs-4dVTl2vaIDYbIwdwiHERfhngK2Yxd2rQyXlxWIknnJiegNWONwSzM/s1600/Skew_t.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 378px; height: 400px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt7mMEXVDWufUFRMhpzyXByTboIbm02CSNaT7w__sye4AqngVJ6pIooyf4o6TnQY791ypl-Zmr3ZbJymbuzXANs-4dVTl2vaIDYbIwdwiHERfhngK2Yxd2rQyXlxWIknnJiegNWONwSzM/s400/Skew_t.JPG" border="0" alt=""id="BLOGGER_PHOTO_ID_5713840543956820658" /></a><br />So we will have to monitor what happens throughout the afternoon tomorrow. A little more sunshine and it could get very active. If the clouds hang around then the likelihood for severe weather will diminish and very little rain will occur until the cold front moves into East Texas early Wednesday morning.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com1tag:blogger.com,1999:blog-7576661293398923145.post-4583799669457546602012-02-21T11:07:00.002-06:002012-02-21T11:08:10.575-06:00Severe weather awareness week: LIGHTNING<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBAC1NVJ9Ej0VOEpCaw9pkSn94U49yzSvXit8eiEUYeJcSPT3kxXVz9aYmV-bFC9J0afQtdT7wkH_jaTxG2FqNzsPFTp2DZBXWdFF8q_5Syi1VAV2OPxQcviZ2mI9Y-VJ-JMuVCkFFh7Q/s1600/Bolt+From+The+Blue.jpg"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 295px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBAC1NVJ9Ej0VOEpCaw9pkSn94U49yzSvXit8eiEUYeJcSPT3kxXVz9aYmV-bFC9J0afQtdT7wkH_jaTxG2FqNzsPFTp2DZBXWdFF8q_5Syi1VAV2OPxQcviZ2mI9Y-VJ-JMuVCkFFh7Q/s400/Bolt+From+The+Blue.jpg" border="0" alt=""id="BLOGGER_PHOTO_ID_5711636793011223906" /></a><br />One of the most deadly of all weather phenomena is lightning. Lighting is basically a large spark of static electricity within the clouds or between the cloud and the Earth. Over the past 30 years lightning has killed an average of 55 people per year but that number continues to drop thanks to educating the public on lightning safety. In fact, last year had the lowest amount of lightning deaths on record with 26. <br /><br />As a thunderstorm develops, air inside the storm moves up and down in the form of updrafts and downdrafts. Inside the currents of air are ice particles, whether small ice crystals or large hailstones. These ice crystals will collide with each other causing a buildup of static electricity, much like what happen when you rub your feet across the floor only to get shocked by the door knob as you reach for it. The thunderstorm is doing the same thing. As the ice particles continue to collide in the storm, some become positively charged and some become negatively charged. The positive charged ice crystals will move towards the top of the thunderstorm while the negative charged ice crystals will settle across the bottom or mid level of the storm. As the storm moves over the ground the surface charge becomes positive. Once the difference becomes great enough a discharge of static electricity will occur just like the shock that comes off your finger as you reach for the door knob. Only in this case the shock is a bolt of lightning that can reach a temperature of 50,000°F. As the air heats around the lightning bolt it will expend very rapidly causing a loud boom or thunder. <br /><br />In some cases the positive charge at the top of the storm can become so great that a large lightning bolt will race from the top of the cloud towards the ground well out ahead of the storm. This is called positive lightning and occurs because the ground well ahead of the storm has not yet become positively charged. In some cases this lightning bolt can hit up to ten miles away from the storm. This is the most dangerous type of lightning as many times it will strike when you don’t know a storm is near you due to the lack of clouds and it usually has the strongest amount of electric current.<br /><br />So next time you hear thunder it is time to move indoors. For every five seconds you can count between lightning and its thunder is a distance of 5 miles. So even the faintest sound of thunder means it is close enough to strike. Also, it is a great idea to wait 30 minutes after the last sound of thunder to make sure the storm has passed to a safe distance.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0tag:blogger.com,1999:blog-7576661293398923145.post-28437964582959791802012-02-20T11:07:00.001-06:002012-02-20T11:07:24.907-06:00What's going on???Not sure why I see Photobucket all over the blog this morning. Might need to update the template. Sorry for the inconvenience.Grant Dadehttp://www.blogger.com/profile/16647180899266401725noreply@blogger.com0