


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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926 FXUS01 KWBC 132002 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 401 PM EDT Wed Aug 13 2025 Valid 00Z Thu Aug 14 2025 - 00Z Sat Aug 16 2025 ...Scattered flash flooding possible across the Eastern U.S. and Deep South today... ...Strong to severe thunderstorms forecast for portions of the Northern Plains this evening and the Upper Midwest tomorrow... ...Heat to shift into the Central High Plains; HeatRisk is forecast to locally reach Major and locally Extreme level in portion of central Florida... A series of cold fronts forecast to advance from the northwest will maintain shower and thunderstorm chances across the Eastern and Southern U.S. to close out the work week. Ahead of these fronts, a large area of warm and very moist air entrenched across the eastern U.S. and Deep South will favor periods of very intense hourly rainfall rates within the stronger cells this afternoon. As such, portions of the Mid-Atlantic (including the southern half of the I-95 corridor) and Lower Mississippi Valley have been upgraded to a Slight Risk (Level 2/4) of Excessive Rainfall today, in addition southern Appalachians and Gulf Coast which were highlighted overnight. By tomorrow, the southward progression of the front should usher in a more stable airmass, in turn decreasing thunderstorm coverage. However, isolated instances of flash flooding remain possible ahead of the front from the Lower Mississippi Valley into the Northeast. Meanwhile, a deepening low pressure system over the Canadian prairies will drive a warm front across the Northern Plains. Severe thunderstorms are still forecast to develop near this boundary from South Dakota into northern Nebraska this evening, where a Slight Risk (level 2/5) of severe thunderstorms remains in effect, primarily for damaging wind gusts and isolated large hail. As the warm front advances eastward and then collides with a cold front pushing in from the Canadian prairies, the severe weather threat will then head further east across the upper Mississippi Valley tomorrow into Friday morning. Cooler temperatures behind this cold front will allow for temperatures to gradually trend below normal across the northern High Plains and especially the Northwest U.S. for the latter part of the week. This will bring a break from the hot weather that portions of the Intermountain West have been experiencing as well. However, the same hot weather that has been over the West will shift east into the Central Plains and the Midwest on Friday. This will bring a couple of days with high temperatures reaching well into the 90s to the High Plains. Across northern Florida, a slight increase of heat and humidity is enough to raise HeatRisk into Major and locally Extreme levels tomorrow and Friday as the Bermuda High builds westward into the Sunshine State. Asherman/Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$