Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 346 AM EDT Thu Jun 26 2025 Valid 12Z Thu Jun 26 2025 - 12Z Sat Jun 28 2025 ...Prolonged and intense heat wave continues into Friday from Midwest to Mid-Atlantic... ...Unsettled weather could produce severe weather and excessive rainfall for parts of the Central and Eastern U.S.... Extreme heat warnings and heat advisories remain in effect for portions of the Mid-Atlantic, Ohio Valley and the Southeast through today--impacting approximately 130 million people. The Ohio Valley is still expected to experience the most prolonged and notable effects from this heat wave. The duration of this heat remains dangerous to anyone without effective cooling and/or adequate hydration as heat related illnesses increase significantly during extreme longer duration heat. Continue to limit outdoor time, stay hydrated, and take action when you see symptoms of heat exhaustion and heat stroke. The extreme heat will moderate across the Mid-Atlantic tonight followed by Friday for the Ohio Valley, due to the weakening ridge aloft. A quasi-stationary surface front draped across the northern tier, shortwave energy riding along the boundary and warm unstable air present at the surface will contribute to scattered to organized thunderstorm activity across much of the Eastern half of the country over the next several days. There's a slight risk (at least 15%) of excessive rainfall leading to flash flooding over parts of eastern Kansas up into Iowa, Wisconsin and northern Michigan/U.P.. The Storm Prediction Center also issued a slight risk (level 2/5) for a small area encompassing northeastern Iowa, far southeastern Minnesota and southwestern Wisconsin, where isolated wind damage will be possible. The threat for flash flooding shifts into the interior Northeast on Friday where a surface wave riding along a warm front will lift up into the region. A slight risk of excessive rainfall is in place across northeastern Upstate New York, and northern Vermont/New Hampshire. A new convective threat develops over the Northern Plains on Friday out ahead of a longwave trough and an emerging surface low pressure system. SPC issued a slight risk for parts of the Dakotas and far north-central Nebraska, where large hail and locally damaging winds are forecast. A degrading upper low will retrograde into the Southeast Coast over the next couple of days. Scattered showers and thunderstorms are expected from the Southeast up into the Mid-Atlantic, where some storms could produce sporadic/isolated wind damage, according to SPC. Continued cloudy and rainy conditions could produce localized flash flooding in New Mexico through Friday, but will also keep temperatures down between 10-20 degrees below average. Kebede Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php