Monday, July 27, 2009

Heavy Rain Possible This Week.

Good Monday Morning East Texas. As advertised last week, a very wet and unsettled weather pattern is setting up for East Texas this week. We are watching a disturbance over the Texas Panhandle this morning that will move in to East Texas this afternoon. Showers and thunderstorms will be likely later today with heavy rain a good possibility. Overnight tonight we will see more storms develop out to our west and move into the area giving us another chance of heavy rain. More disturbances are lined up to our north and west and will continue to slide across East Texas throughout the work week. The threat for severe weather is low however, if we see any breaks in the clouds today or tomorrow allowing for additional daytime heating, the atmosphere will become more unstable than forecast and storms could be stronger with a hail and high wind threat. We could also see a flooding threat develop across East Texas this week. Flash Flood watches will probably be issued before the week is out for parts of the area as rain fall could reach 6 inches plus is some areas, especially across Northeast Texas. Stay tuned to your East Texas News Leader for the latest weather information throughout the week.

Saturday, July 25, 2009

Tonight's Pop Up Severe Rusk County Storm!

As fast as this storm developed, this storm died. Although I have not had any severe weather reports as of yet, I would not be surprised if someone in northern Rusk County received quarter size hail and very strong winds as this storm collapsed. I need to start taking my camera with me where ever I go. This storm was very impressive from Downtown Tyler looking east. I did make a couple of movies from radar grabs so you can see how fast this storm formed and died out. Got to love summer time pop corn storms but sometimes, they get out of hand.

***Special Thanks to Dave and Buffy Dyess for the photos***

Thursday, July 23, 2009

Severe Storms Pound East Texas

Tuesday night’s storms across East Texas provided much needed rain to many but also brought with them a round of severe weather. Numerous reports of wind damage accompanied these storms as they developed along the I-30 corridor and moved south into the Tyler Longview area. There were even a few reports of hail up to the size of quarters in Upshur County and yours truly experienced penny size hail along Cumberland Road in Tyler.

The first photo below was taken off of Hwy 155 north of Big Sandy looking towards Gilmer. Lots of low hanging clouds giving an ominous appearance to the approaching storm.

Looking Towards Gilmer Just North Of Big Sandy

The next photo taken was taken in the same spot but looking more to the east than northeast, under the updraft base. Weak rotation was seen but nothing to signal the possibility of a tornado developing.

Looking Towards Gilmer Just North Of Big Sandy

As the storm continued south it continued to strengthen producing numerous cloud-to-ground lightning strikes and very strong winds. We were continuously buffeted by winds between 50 and 60 mph. Limbs were being snapped off and a few trees were knocked down along Hwy 80 as we raced east from Big Sandy to Gladewater. Below are a few photos sent to me from Mack and Jeanette Rose of Gilmer.

Once in Gladewater we took Hwy 271 southwest towards Tyler. Just south of Interstate 20 we saw a feature that really caught our eye. There appeared to be a tornado on the leading edge of the storm but after watching it for a minute it was easy to see there was no rotation and this feature was what we call scud, or scattered cumulus under deck. Many times this feature will take on the shape of a funnel or tornado. Below is a shot of this feather as it moved north of Interstate 20.

Low clouds called scud becoming a tornado look-a-like

The storm we had been chasing began to weaken as we moved into Smith County but another storm along the Smith Wood County line began to strengthen. It is this storm that would produce the widespread damage and power outages across South Tyler. Below are a couple of radar animations. One, of the storm as it moved through the Tyler area, and the other is a volumetric scan where you can see the collapse of one storm which helped develop the Tyler storm. Then you can see the Tyler storm collapse which could have caused even more damage in the form of a microburst.

Now let’s take a look at the velocity data from Tuesday night’s storms, or speed and direction of the wind flow in the storms. In these photos the green colors are winds blowing towards the radar and the red colors are winds blowing away. The brighter the color, the stronger the wind. Another important fact to understand is these images are sampled in the storm around 13,000’ above the ground, so we don’t know exactly what was occurring at the surface. In the 1st photo we see red colors over Tyler indicating winds blowing away from the radar site indicating inflow to the developing storm along the I-20 corridor. Also you notice a large area of green east of New Chapel Hill indicating winds blowing towards the radar from outflow of a weakening storm over northwest Rusk County.

Over the next two frames, it looks as though this westward moving outflow boundary may have induced rotation in the Tyler storm as it continued to move south-southwest. The second of the two frames shows a tight couplet forming over southern Tyler near the intersection of Cumberland and Broadway. I was at this intersection and witnessed an abrupt change in the winds from the north to the south to around 60 mph. So there could have been rain wrapped rotation moving through south Tyler.

Over the next 15 minutes from this point the storm rapidly died down and can be seen with much weaker wind speed in the last velocity frame.

So was there a tornado in South Tyler Tuesday Night? Well, radar data hints that there was rotation in the storm 13,000’ above the surface which means there was a possibility this rotation reached the ground. I will tell you that all the damage I was able to see the next day indicated the most likely scenario was straight-line winds. I saw very little evidence of swirling wind from damage. However, radar data and the abrupt change in wind speed and direction makes me think there could have been a weak tornado moving through South Tyler. Officially tough this one will go down as a severe thunderstorm with straight-line wind damage.

Damage Photos from Tyler.

Tuesday, July 21, 2009

Severe Storms...Isolated Tornado Possible

A very unusual weather pattern is shaping up across East Texas for this late July afternoon. It is almost unheard of to get a strong jet stream to move into the southern plains this late in the season but, that is what is about to happen. So what does all this mean? It means there is a chance of severe weather across East Texas including tornadoes later on this afternoon.

Possible Tornado Watch This Afternoon
The line of storms from this morning has used up a good bit of the energy in the atmosphere available for storms but clearing skies behind this line is allowing the sun to recharge the atmosphere. A cold front in Southern Oklahoma will sag south this afternoon into the northern counties of East Texas acting as a firing mechanism for additional storms. The amount of available energy for storms along the Red River Valley is already ample for severe storm development. In a normal late July weather pattern, any severe storm that develops would be what we call a pulse storm, meaning they quickly pulse up to severe limits and die out almost as fast. Thanks to a stronger upper level jet stream today, the storm’s core will be pushed away from the updraft allowing it to live longer. Thanks to an area of low pressure at the surface to our northeast, we have southwesterly winds at the surface. These winds quickly change direction as you increase in height throughout the atmosphere giving use enough wind shear for supercell thunderstorms, which we mainly find in East Texas during the Spring months. With supercells, the threat for strong gusty winds, large hail, and even isolated tornadoes will be possible. Stay tuned to your East Texas News Leader throughout the day for the latest.

Monday, July 20, 2009

Sunday's Severe Storms

Severe Storm Over Lake Palestine
A few severe thunderstorms developed yesterday afternoon so I decided to head out and see what I could find. My first stop was the Marina at the Villages on Lake Palestine to get a great view of a developing storm which would become severe and produce numerous hail reports, at times to the size of golfballs near Frankston. I continued to watch this storm intensify and decided to see what it had to offer. So I left the Marina and crossed Lake Palestine on hwy 155. As I passed through Coffee City Small Hail began to mix in with very heavy rain. As the storm continued to intensify the hail became larger, around 0.5” in diameter. As I entered the small town of Berryville, hail reached penny size so I pulled off the road so I could make a quick call to report the severe weather. Shortly after the hail reached quarter size, the largest I would see this day. I was concerned for my windshield but I came through the storm without a crack. A couple of miles down hwy 155 the hail reached golfball size in Frankston so I am glad I stopped when I did, doubt the windshield would have survived. Below are a few pictures of yesterday's storms.

Storm Over Tyler Sunday Afternoon

The Beginning of a Severe Thunderstorm

Under The Core With Rain and Hail