Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EDT Sat Aug 16 2025 Valid 12Z Sat Aug 16 2025 - 12Z Mon Aug 18 2025 ...Rounds of severe thunderstorms with heavy rain possible over the northern Plains and Upper Midwest today and Sunday... ...Hazardous heat in the Mid/Lower Mississippi Valley through early next week... A frontal system is forecast to bring showers and thunderstorms from the Pacific Northwest to the Northeast over the weekend, with chances for isolated to scattered severe thunderstorms over the northern Plains and Upper Midwest. The front will likely progress faster across the Northwest and Northeast while remaining nearly stationary over the north-Central U.S. as several waves of low pressure develop over the region. The slow nature of the front and repeating rounds of storms will create a flash flood threat from the northern Plains to the Upper Midwest, and isolated to scattered instances of flash flooding will be possible. By Monday, the front should gain some southeastward momentum, and showers and storms will shift into the Great Lakes region while the north-Central U.S. dries out. Precipitation chances will also persist through the weekend for the Southwest and Southeast. Monsoonal moisture across the Four Corners region will support scattered showers and isolated thunderstorms, and a weak area of low pressure and trailing frontal boundary lingering just off the Southeast Coast will support scattered showers and thunderstorms across Florida and along the Southeast Coast. Due to expected precipitation and cloud cover, the West Coast and portions of the Upper Midwest will likely see below normal temperatures this weekend. Below normal temperatures may also nudge into the Northeast in the wake of a cold front passage on Monday. Above normal temperatures are forecast for the rest of the Central and Eastern U.S., with hazardous heat possible in the Mid/Lower Mississippi Valley through the weekend and early next week. High temperatures are forecast to range from the 90s to near 100 degrees with heat index values 105-110 degrees. This level of heat will create Major to Extreme HeatRisk across the region, which could be dangerous to anyone without adequate cooling and/or hydration. Dolan Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php