The Storm Prediction Center has indicated that they will likely be issuing a tornado watch for parts of Southeast Texas within the next few hours. Conditions are becoming more favorable for the development of a few severe thunderstorms. The primary threat in Southeast Texas would be quarter size hail and localized damaging wind gusts over 60 MPH. The tornado threat will increase as storms approach the Louisiana border with the highest tornado threat in Louisiana and Mississippi. Severe storms should exit Texas to the east by 4 PM but we could continue to see sub-severe storms in Northeast and East Texas through early this evening.
MESOSCALE DISCUSSION 0033
NWS STORM PREDICTION CENTER NORMAN OK
1059 AM CST THU JAN 21 2016
AREAS AFFECTED...SE TX...LA
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 211659Z - 211900Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...THE SEVERE THREAT ACROSS SE TX AND WRN TO CNTRL LA WILL
INCREASE OVER THE NEXT FEW HOURS. TORNADOES...ISOLATED LARGE HAIL
AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER STORMS. A TORNADO
WATCH WILL LIKELY BE NEEDED ACROSS THE REGION LATE THIS MORNING.
After a few days of quiet and pleasant weather to start the work week, the chance for some light snow, some drizzle/showers and a few thunderstorms returns to the forecast. A weak cold front will arrive tonight bringing a chance for light rain at first across the panhandle sometime after 10pm, then transitioning to a light snow before daybreak on Thursday. Accumulations will be light and generally less than 1/2 inch with no major travel impacts expected. A surface low will be drifting east across north Texas overnight as well which will bring a chance for patchy areas of dense fog and drizzle out ahead of the front early on, then scattered showers with maybe a few rumbles of thunder mixed in beyond daybreak tomorrow.
Rain chances will continue across the eastern half of the state tomorrow afternoon as the front continues to move south reaching the upper coast by early evening. Winds behind the front will gust into the 30 to 40mph range tomorrow across the panhandle by early afternoon which may require a Wind Advisory. We’ll update you on that if one is issued during the early morning update. The main hazard tomorrow afternoon will be the marginal chance for seeing a few strong to severe storms to develop across southeast Texas. The timing right now looks to be between 11am and 4pm tomorrow afternoon. North/Northeast Texas also has a chance at seeing a few strong storms as well, but being that this will happen behind the front, the threat for any severe weather is greatly diminished. David published a blog with specifics earlier this evening. In case you missed it, check it out here: http://texasstormchasers.com/2016/01/20/42525/
Lows tonight will drop into the 30s across the panhandle and far western Texas, with mainly 40s across central and southwest Texas, and we’ll see much warmer lows in the 50s to low 60s for the coastal plains and deep south Texas. Highs behind the front tomorrow will struggle to get out of the 40s, plus we’ll have the strong north winds to contend with which will make it feel much colder. Ahead of the front, quite warm and humid with highs in the 70s. In looking ahead…Friday through Sunday, conditions are expected to remain dry with pleasant temperatures returning, especially across the western half of the state. All in all, it looks like we’ll have a very nice weekend ahead…perfect for making outdoor plans!
Wednesday’s Forecast & A Look Ahead at Snow Chances This Weekend!
Wednesday is shaping up to be another beautiful day across a majority of the state. We’ll see the return of cloud cover and rain chances by tomorrow evening for deep south Texas and along the central Texas coastal plains, but everywhere else, skies will be mostly clear with no chance for rain. Temps will be above average once again tomorrow and through early Friday before the first of two cold fronts impact the region.
The chance for rain, and possibly a few thunderstorms mixed in, will return by Thursday afternoon ahead of cold front #1 which will arrive in tandem with a weak-ish upper level disturbance. We won’t have much to work with in regards to instability, so widespread coverage of strong storms is not expected. Rain chances will be highest along the coast, decreasing in probabilities the further north you get. Cold front #1 will knock temps down a few degrees overnight Thursday into Friday, but for the most part will do little more than shift our winds from the west/northwest and drag drier air into the region.
The forecast for this coming weekend…Friday night through Saturday…remains a bit unclear. We are expecting cold front #2 to arrive late Friday into early Saturday, and it is forecast to be much stronger than Thursday’s front. What remains unclear is will the next upper level disturbance be enough to generate winter weather across the northern half of the state. Since the forecast models for the past several days have been flip flopping back and forth on this probability, forecast confidence for any snow and how much snow is fairly low at this time. Both models have been presenting a fair amount of disagreement on where the coldest air…basically the 32 degree line…will be at the time precip is still falling late Friday and through Saturday. It seems reasonable to assume that the cold air will likely outrun any of the forecast model timing because it frequently does, so we may very well have sufficient cold air in place in time for the precip to begin falling…but that’s not the only issue. What isn’t as easy to assume right now is where the upper level disturbance will be, and will it have enough lift and wrap-around moisture to generate widespread precipitation. Yesterday, the forecast models were much more generous with the precipitation; however for today, much less so…almost a complete 360 degree difference. So, with a “split down the middle” assumption that the atmosphere may be able to squeeze out a little bit of precip, most of the local forecasters are going with a slight chance of light snow across the panhandle late Friday and possibly some light snow along the Red River counties by Saturday morning. The surface temperature profiles across the Red River counties, and for the counties surrounding the DFW metroplex, all look to be too warm for any snow to stick. So, IF we get any snow, it will likely be mixed with rain and will melt right away. This will bear watching closely as better data feeds into the forecast models over the next couple of days. That said, assume there will be some updates to what you’re seeing below.
A Few Severe Storms Possible This Evening; Snow in the Panhandle
I expect most of the daytime hours will be capped with thunderstorms holding off until near or after 5 PM. The experimental HRRR weather model run seems to show the situation well. Several of the past model runs (hourly) begin to develop thunderstorms around the Houston Metro at about 5 PM. Storms would move northeast around 25-35 MPH and expand in both intensity and coverage east of Houston towards Nacogdoches. By 9 PM it looks like several showers and thunderstorms may be underway from near Longview south into Southeast Texas to Beaumont. Activity should continue to move east and exit Texas by midnight. The strongest storms this evening could produce hail up to the size of half-dollars (1.25″ in diameter) and localized wind gusts of 50-60 MPH. The tornado threat is very low but if we were to have a brief tornado it would likely be in Southeast Texas. I wouldn’t be surprised to see the Category 2 risk extended further north into East Texas with the strongest storms capable of producing hail this evening.
Chance of precipitation through this afternoon. Click image for full-resolution version.
Chance of precipitation through this evening and tonight. Chance of precipitation through this afternoon. Click image for full-resolution version.
Chance of precipitation through on Saturday. Chance of precipitation through this afternoon. Click image for full-resolution version.
Widespread severe weather is not expected with this event but there will likely be a larger area of rain and sub-severe storms. Rain totals across Northeast Texas, East Texas, and Southeast Texas will likely be in the 0.75 to 1.25 inch range. No rain accumulations is expected along or west of Interstate 35. A trace to around a tenth of an inch of liquid-equivalent precipitation is possible across the Texas Panhandle through Friday – most of that will fall as snow.
Snow will likely begin to fall across the western Texas Panhandle later this morning. By early afternoon snow will likely be underway across the Northwest Texas Panhandle into the northern Panhandle. Temperatures will be near or just below freezing at that point. Widespread snow will continue through early this evening across the northwest half of the Texas Panhandle. By midnight snow will have decreased in coverage with pockets of light snow possible across all the Panhandle into the Caprock. Snow accumulations up to five inches will be possible across the Northwest Texas Panhandle. A dusting of snow up to an inch will be possible from Amarillo and points west and north. Some of this snow will likely accumulate on roads creating slick conditions this afternoon into tonight.
A Couple Strong to Marginally Severe Storms Possible Friday Evening in East & Southeast Texas
We’ll start out looking at the Storm Prediction Center’s outlook for tomorrow. After that I’ll discuss some of the aspects of tomorrow’s setup. Unlike the December 26th setup we’re not going to be dealing with a spring-like system. Tomorrow will be much more tame and in line with what we expect in the winter months. A marginal risk of severe weather has been issued for East Texas, Southeast Texas, and part of the Brazos Valley. On a five level risk system tomorrow’s setup is at a level one – the lowest risk. Tyler, B/CS, Houston, Lufkin, Pittsburg, and Port Arthur are a few cities in the risk. Tomorrow’s storm setup is marginal but we could see a few storms become strong to borderline severe. Those stronger storms would likely be hailers with stones up to the size of quarters. Some wind gusts up to 50-60 MPH could also occur. A very low risk of a brief tornado may develop across Southeast Texas. While a brief tornado may occur the overall tornado risk is very low.
Surface dewpoint values from the 12Z 4KM NAM Friday Evening
One factor limiting the severe weather threat on Friday will be limited moisture return. As is common for the winter months moisture levels will be on the low-end for a severe weather threat. Dewpoint values along the coast and in Southeast Texas should be in the low to mid 60s by dinnertime Friday. Further north into East and Northeast Texas dewpoint values will range from 54 to 58 degrees. I like to see values over 60 degrees for more organized severe thunderstorms during the cool season. In the spring and summer months you ideally want to see dewpoints above 65 degrees for significant, surface-based supercell potential. The depth of the moisture coming in from the northwest Gulf will also limit the severe weather potential. We’ll keep an eye on things along the coast and just inland across Southeast Texas as that is where moisture levels will be highest tomorrow evening.
Potential Instability Levels around 9 PM Friday
Even though moisture levels will be limited there will be some instability elevated above the surface across East Texas. That instablity will likely be above a stable layer of air near the surface. A couple strong elevated storms would be possible in that enviornment with hail the threat. The threat for damaging winds and tornadoes is extremely low with elevated storms.
Rain amounts up to 0.75″ will be possible across Northeast Texas, East Texas, and Southeast Texas. Widespread severe weather is very unlikely but there may be numerous showers and thunderstorms across Northeast Texas, East Texas, and Southeast Texas Friday Evening.