643 FXUS01 KWBC 231928 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 327 PM EDT Thu Jul 23 2026 Valid 00Z Fri Jul 24 2026 - 00Z Sun Jul 26 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 is on a westward path to Texas along the northern Gulf Coast and bringing showers along the Gulf Coast near Louisiana and Texas and gusty winds. 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 slow moving front is expected to drop into the Tennessee Valley, Southeast and Mid-Atlantic today before stalling by Friday. Warm, tropical moisture advecting northward from Bertha will pool along this frontal boundary and will fuel 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 rounds 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. Deep monsoonal moisture will be persistent over the next few days thanks to southerly flow along the western flank of the upper-level ridge centered over the Rockies. 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. The multi-day heatwave will continue for much of the southern tier of the country and will spread northward through the Great Basin and into the Northern and Central Plains Friday into the weekend. Daily max temperatures of mid-90s to mid-100s can be expected 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/Campbell Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$