Let me start out this noon update by saying we currently have no severe weather in the state this morning. We did have a potent severe thunderstorm set up over Van Zandt county between 9 and 10 AM with gusty winds and brief rotation. As of 12 PM we have a large area of light to moderate precipitation across East Texas. The strongest cores in this precipitation shield are producing cloud to ground lightning and heavier rain. Isolated heavy shows continue across parts of the D/FW Metroplex where temperatures have remained in the low to mid 70s after precipitation earlier this morning.
I’ll also say today is NOT expected to be a big tornado day. Low level winds are simply too weak to support a high-end tornado threat. The two primary severe weather hazards will be large hail and damaging wind gusts. While a few tornadoes are certainly possible I want to emphasis there is no reason to be worried or scared.
So how does the rain earlier this morning impact the severe weather setup later this afternoon? Well there have been a couple changes that we’ll talk about. The primary implication from this morning’s storms is an outflow boundary that has pushed south of the D/FW Metroplex to between Hillsboro and Waco. On the north side of this boundary surface temperatures are about five to ten degrees cooler than to the south of the boundary where temperatures have climbed into the 80s. Overall this results in the most significant severe weather threat shifting a bit south. As such the severe weather outlooks have been adjusted accordingly from the Storm Prediction Center.
Speaking of severe weather outlooks let’s take a look at the brand new one just issued! I’m doing something different now in that I’ve created graphics for each specific severe weather hazard including the potential for tornadoes, large hail, and damaging wind gusts. The result is three different graphics depicting each severe weather hazard versus just the overall risk today. This means you may have an enhanced risk for damaging wind gusts this evening but a low tornado threat for example.
Overall there is an enhanced risk of severe weather across Central Texas, parts of North Texas, and East Texas later today. As rain continues to move out early this afternoon the atmosphere should begin to quickly destabilize. South of the outflow boundary where temperatures have warmed into the 80s the atmosphere is already priming itself. The most significant severe weather threat today could evolve in Central Texas along and south of this outflow boundary where the atmosphere will be extremely unstable. Initial thunderstorms may develop as soon as 3 PM (or in the 4-5 PM timeframe). These discrete storms will likely be supercellular with a threat of very large hail, damaging wind gusts and even the possibility of a tornado or two.
As thunderstorms congeal later this evening into one or more complexes or clusters the threat for damaging wind gusts will increase while the threat for very large hail will decrease. Storms will likely move in an eastward fashion with dominant storms turning to the east/southeast. We’re continuing to monitor trends early this afternoon for signs of mesoscale factors such as small outflow boundaries or other atmospheric phenomena that could locally enhance any severe weather threat. For now I’ll leave you with the meteorological discussion from the Storm Prediction Center regarding the latest severe weather threat for today. I’ll have another update out around 2 PM which will be more specific regarding short-term trends. For now we’re in a waiting game.
SEVERE THUNDERSTORMS ARE EXPECTED ACROSS PORTIONS OF TEXAS EASTWARD
INTO THE LOWER MISSISSIPPI VALLEY. VERY LARGE HAIL AND DAMAGING
WINDS WILL BE THE MAIN THREATS…BUT A FEW TORNADOES ARE POSSIBLE.
ADDITIONAL…BUT MORE ISOLATED…STRONG TO SEVERE STORMS WILL BE
POSSIBLE IN THE NORTHERN AND CENTRAL ROCKIES…THE HIGH PLAINS…AND
ACROSS PARTS OF MID-ATLANTIC STATES TO LOWER GREAT LAKES REGION.
…SOUTHERN PLAINS TO LOWER MS RIVER VALLEY…
THE DECAYING REMNANTS OF AN MCS/TRAILING COLD POOL CONTINUE TO
SPREAD SOUTHEASTWARD ACROSS PARTS OF NORTH TX/FAR SOUTHERN OK LATE
THIS MORNING. INITIAL SEVERE THREAT THIS AFTERNOON WILL BE IN
ASSOCIATION WITH WHAT MAY BE AN UPSCALE DEVELOPING QUASI-LINEAR
COMPLEX AND/OR AN MCV ACROSS PARTS OF EAST TX INTO LA AND PERHAPS
OTHER PARTS OF THE MID-SOUTH/LOWER MS RIVER VALLEY. THE PRECEDING
AIR MASS ACROSS THE CORRIDOR WILL CONTINUE TO STEADILY
WARM/DESTABILIZE COINCIDENT WITH AMPLE HEATING AND LOWER TO MIDDLE
70S F SURFACE DEWPOINTS. DAMAGING WINDS/BOUTS OF SEVERE HAIL WILL BE
FARTHER WEST…ADDITIONAL INTENSE STORM DEVELOPMENT IS ANTICIPATED
ESPECIALLY ACROSS PARTS OF CENTRAL/WEST-CENTRAL TX INTO LATE
AFTERNOON/EARLY EVENING. THIS WILL BE VICINITY OF THE SYNOPTIC FRONT
IN CONJUNCTION WITH RESIDUAL INFLUENCES OF EARLY DAY
OUTFLOW/DIFFERENTIAL HEATING. THIS SCENARIO WILL LIKELY BE AIDED BY
THE APPROACH OF A SHORTWAVE TROUGH/SPEED MAX…WITH ATTENDANT
STRONGER MID/HIGH-LEVEL WESTERLIES…NOTED TO BE MOVING EASTWARD
OVER NM AT MID-MORNING. SUPERCELLS CAPABLE OF LARGE HAIL AND
POSSIBLY A COUPLE OF TORNADOES WILL INITIALLY BE POSSIBLE…WITH
STORMS LIKELY GROWING UPSCALE AND ADDITIONALLY POSING A DAMAGING
WIND RISK AS THEY SPREAD GENERALLY SOUTHEASTWARD TONIGHT. PENDING
EARLY AFTERNOON TRENDS AND GREATER CONFIDENCE IN A PEAK RISK
CORRIDOR…AREAS SUCH AS WEST-CENTRAL/CENTRAL TX COULD WARRANT AN
UPGRADE TO MODERATE RISK /MAINLY FOR VERY LARGE HAIL/ WITH THE 20Z
DAY 1 UPDATE.