429 FXUS01 KWBC 250535 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 134 AM EDT Tue Aug 25 2026 Valid 12Z Tue Aug 25 2026 - 12Z Thu Aug 27 2026 ...Dangerous record-breaking heat continues across the south-central U.S. into the Southwest this week... ...Flash flooding and severe weather threats continue across portions of the Southwest and into the Rockies/Plains, Upper Midwest, and Southeast through Wednesday... A strong upper-level ridge will remain anchored across the Southwest into south-central U.S. into late week. This will maintain an abnormal hazardous heat across the region, with daytime highs of 100-110 across the Southern Plains, while portions of the Southwest will reach up to 115. With overnight temperatures providing limited relief, heat-related illness may increase, especially for those without proper hydration and adequate cooling. Furthermore, widespread Major to Extreme HeatRisk is forecasted for much of the Southwest into Texas and Southern Plains through late week. See the latest Key Messages linked at the bottom of the discussion for more information. Farther north, the troughing over the Northwest and northern Rockies will support a more active pattern from the northern and central Rockies/Plains into the Upper Midwest as moisture continues to deepen along the frontal boundary. Increasing instability will also support organized convection, that may lead to flash-flooding concerns across portions of the central/southern High Plains through Wednesday. Additionally, the system will bring the risk for severe thunderstorms across the south/central Plains into the Upper Midwest on Tuesday, and shifts into the Great Lakes/Ohio Valley on Wednesday as the frontal boundary moves eastward. Across the Southwest and portions of the Rockies/Plains, monsoonal moisture will continue to move northward along the western periphery of the ridge and interact with embedded shortwave energy. This will lead to daily scattered showers and thunderstorms through Wednesday. Organized convection may lead to locally heavy rainfall rates, which will continue to pose isolated flash-flooding concerns, particularly over terrain and areas with wet antecedent conditions. Father east, increasing instability and persistent Gulf moisture along a slow-moving frontal boundary will support repeated showers and thunderstorms across the Southeast into Lower Mississippi Valley and portions of the Southern Plains. Therefore, the risk for severe thunderstorms, damaging winds, and isolated heavy rainfall/flash-flooding will continue for portions of the Lower Mississippi Valley and the Southeast through Wednesday. Oudit Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php Extreme Heat Key Messages available at: https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png $$