915 FXUS01 KWBC 250536 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 135 AM EDT Sat Jul 25 2026 Valid 12Z Sat Jul 25 2026 - 12Z Mon Jul 27 2026 ...Chances for showers and thunderstorms across the northern Rockies/Plains into Upper Midwest this weekend... ...Risk of flash flooding expected across Southeast and southern Mid-Atlantic near a stalled frontal boundary... ...Active monsoonal moisture fuels thunderstorms over the Southwest and into portions of the Intermountain West and Rockies... ...Hazardous heat continues over parts of southern U.S. and builds over the Great Basin and Northern Plains through the weekend... The broad upper-level ridge will continue to dominate central/southern U.S., while troughing continues over eastern U.S. The embedded shortwave disturbances across northern U.S. will drive a frontal boundary eastwards from the Northern Rockies/Plains into the Upper Midwest/Great Lakes on Saturday. Low-level moisture pooling along the boundary, combined with strong daytime heating and instability, will support isolated thunderstorm development across portions of Northern Rockies into the Upper Midwest, with a chance for large hail and damaging gusty winds. The severe weather threat increases on Sunday, as several shortwave disturbances shift eastward and mid-level flow increases, reinforcing organized thunderstorms from the Upper Mississippi Valley into the Upper Midwest. These storm may also produce heavy rainfall, damaging wind gust, and isolated instances of flash flooding where antecedent soils are saturated. As the front moves into the eastward by late Sunday into Monday, showers and thunderstorms may develop along the boundary across portions of the Ohio Valley into the Mid-Atlantic. Further south, a secondary quasi-stationary front will drape across the Tennessee Valley into the south Mid-Atlantic and the Southeast on Saturday. Persistent southerly flow ahead of the approaching front will maintain a warm and humid air mass. With abundant moisture, slow storm motions, and high rainfall rates, a Slight Risk (level 2/4) of excessive rainfall have been placed for scattered instances of flash flooding over portions of the eastern Carolinas and the Southeast, while a Marginal Risk (level 1/4) includes portions of the Tennessee Valley. Flash flooding concerns continue for portions of Florida on Sunday as a shortwave trough and the stationary front continues to produce showers and thunderstorms. Across the southwest, the active monsoonal pattern will continue through the weekend. The deep tropical moisture circulating around the southern periphery of the ridge and instability will support scattered thunderstorms across the Four Corners into the central Plains. These storms will be capable of producing locally heavy rainfall, especially over burn scars and slot canyons where rapid runoff and flash flooding may occur. Additionally, Storm Prediction Center has highlighted portions of Arizona with a severe thunderstorm threat, with a potential for strong to severe winds for Saturday. Dangerous heat continues across much of central U.S. into portions of southern U.S. this weekend with widespread Major HeatRisk, with isolated Extreme HeatRisk areas across the Rockies/Plains into the Upper Midwest, Mississippi Valley, and the Gulf Coast. Highs are expected to reach upper 90s to lower 100s across much of central U.S. and portions of southern U.S., with isolated areas in the Desert Southwest seeing 115-120 degrees. High temperatures combined with high humidity can raise heat indices to 105 to 115 degrees, which will pose health risk concerns to anyone without adequate cooling or hydration. Oudit Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$