781 FXUS01 KWBC 230555 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 154 AM EDT Thu Jul 23 2026 Valid 12Z Thu Jul 23 2026 - 12Z Sat Jul 25 2026 ...Tropical Storm Bertha may lead to isolated flash flooding, tropical storm conditions, and coastal flooding along the Gulf Coast and into southern Texas... ...Risk of flash flooding expected across portions of the southern Mid-Atlantic/Carolinas, Tennessee Valley, and the Southeast through Friday... ...Monsoonal thunderstorms continue over the Southwest, Great Basin and parts of the Plains... ...Hazardous heat continues over parts of the Southern Tier; builds over the Great Basin and Northern Plains Friday... Tropical Storm Bertha will continue to track along the northern Gulf Coast on Thursday, bringing showers along the Gulf Coast near Louisiana and Texas. Areas along the Gulf Coast have issues a tropical storm warning for their coastal waters near Louisiana and upper Texas Gulf Coast through late Thursday. By Friday, deep tropical moisture from T.S. Bertha combined with embedded upper-level disturbances and quasi-stationary front will support another round of slow-moving thunderstorms capable of producing locally excessive rainfall and coastal flooding along southern Texas. A frontal passage will drop into the Tennessee Valley/Southeast and extend into the Mid-Atlantic on Thursday and become quasi-stationary. The slow moving front will pool warm tropical moisture along the boundary, favoring widespread showers and thunderstorms. The combination of unstable airmass and sufficient mid-level moisture may lead to high rain rates and repeated rounds of convection, which can bring an increased risk for flash flooding across portions of southern Mid-Atlantic, the Carolinas, and the Southeast. The frontal boundary will also extend into parts of the central Plains, bringing chances for showers and thunderstorms. The shortwave disturbances will also support multiple round of the convection, which may lead to flash flooding and a chance for severe thunderstorms across the central/southern Plains. On Friday, The excessive rainfall threat continues as the frontal boundary stalls and instability increases, leading to another round of heavy rainfall across the Southeast. Across the western U.S. persistent southerly flow along the western flank of the upper-level ridge centered over the Rockies, will continue to transport deep monsoonal moisture northwards into parts of the Great Basin and Southwest on Thursday. Daytime heating combined with terrain-induced lift, will aid in showers and thunderstorm development, which will bring a risk for scattered flash flooding. On Friday, the risk expands into the central Plains/Mid-Mississippi Valley as the moisture interacts with the frontal boundary and shortwave troughs, leading to organized thunderstorms across the area. Additionally, over into the northern tier, a shortwave trough will bring a chance for severe thunderstorms across the Dakotas into parts of Minnesota on Friday. Hazardous heat continues this week over the Southern Tier of the U.S. before beginning to expand northward through the Great Basin as well as across the Northern and then Central Plains Friday into the weekend. Forecast highs range in the mid-90s to mid-100s with heat indices exceeding 105-115 degrees for some locations. Record warm overnight lows in the 75 to 80 degree range will provide little relief from th heat overnight. Widespread major to locally extreme HeatRisk (levels 3 and 4/4) is expected which indicates a level of heat dangerous to anyone without adequate cooling or hydration. Continue to monitor WPC's Key Messages for more details and updates on the heat. Over the Pacific Northwest, cooler temperatures return as a cold front moves into the area, bringing below average temperatures by the weekend. In addition, the Midwest to Mid-Atlantic/Northeast will see below average temperatures following a cold front passage, with highs in the 70s to low 80s through Friday. Oudit/Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$