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FXUS01 KWBC 161950

PMDSPD



Short Range Forecast Discussion

NWS Weather Prediction Center College Park MD

350 PM EDT Thu May 16 2024



Valid 00Z Fri May 17 2024 - 00Z Sun May 19 2024



...Dangerous and life-threatening flash flooding likely today for

portions of eastern Texas and western Louisiana...



...Potentially significant heavy rainfall threat spreads into

portions of southern Mississippi and western Alabama tomorrow...



...Sweltering heat continues across South Florida and South Texas

into this weekend...



The main weather story today remains the dangerous and

life-threatening flash flood potential over the Lower Mississippi

Valley into the overnight hours as widespread thunderstorms batter

areas which are very vulnerable to additional rainfall. Since the

upgrade to a High Risk (level 4/4) of Excessive Rainfall last

night, little has changed this afternoon regarding the placement

and severity of the flash flooding threat in eastern Texas and

western Louisiana. Radar across east-central Texas this afternoon

depicts an expansive thunderstorm complex growing along a warm

front, with very moist and unstable air feeding into it to support

continuous storm development this afternoon. Going into the

evening and overnight hours, repeating of these thunderstorms

containing very heavy rainfall rates within the complex will lead

to rainfall amounts of 5-8" today within the High Risk area over

eastern Texas and western Louisiana before the thunderstorms

migrate eastward by tomorrow morning. Remember, High Risks for

Excessive Rainfall are a BIG DEAL: 1/3 flood related fatalities

and 4/5 flood related damages occur in WPC High Risks, so pay

attention to the latest warning information and NEVER drive or

walk into floodwaters. Flooding aside, the same storms are also

capable of producing a few tornadoes, severe wind, and hail, with

the Storm Prediction Center maintaining an Enhanced Risk (level

3/5) of severe weather over much of the same area today. 



By tomorrow morning, the threat of significant flash flooding will

spread east into southern Mississippi and western Alabama as the

aforementioned warm front stalls out over the Southeast. Once

again, a very moist and unstable atmosphere appears primed to

support bouts of prolific heavy rainfall, with multiple rounds of

storms expected as multiple disturbances aloft traverse the area.

When combined with saturated soils from recent heavy rainfall, a

Moderate Risk (level 3/4) is in effect tomorrow with areal

rainfall amounts upwards of 2-5" (locally up to 7") possible. It

should be noted that there is some uncertainty with where the

heaviest rain falls owing to how the current storms in Texas

behave later today, so stay tuned for any adjustments to the

forecast. Once again, severe weather will also be an issue south

of the warm front across the Gulf States, with a Slight Risk

(level 2/5) in effect for few tornadoes, very large hail, and

damaging wind.



The same warm front driving the thunderstorms will also contribute

to sweltering heat in South Florida and Texas. Recent experimental

NWS HeatRisk guidance continues to suggest moderate to locally

major heat related impacts will continue across these areas at

least through Saturday due to the combination of heat indices

eclipsing 100 degrees, with little overnight relief expected.   



Asherman



Graphics available at

https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php



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