Friday, December 7, 2012

Very Active Weather Pattern The Next Few Days

A 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.

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.

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.

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.

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.

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.

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.

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.

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.

1 comment:

Eric said...

Thanks for the post!