Weather across America 7/27/25

(NATIONAL) Dangerous, long-lasting extreme heat expected across the Southeast, severe weather and flash flooding possible for portions of the Upper Midwest and Mid-Atlantic.

Thunderstorms are likely to form somewhere in northern Minnesota Sunday afternoon and potentially congeal into a southward-moving MCS Sunday night. There's a slight risk (at least 15% chance) of excessive rainfall leading to flash flooding over parts of northeastern Minnesota where saturated soils are more susceptible to runoff. There's also a slight risk (level 2/5) of severe thunderstorms across many of the same areas, due to the threat of wind-damage and isolated large hail.

Some weak impulses embedded within the aforementioned upper ridge should generate some scattered to isolated thunderstorms across the Ohio Valley and Northeast/Mid-Atlantic Sunday afternoon, where relatively high soil moisture should allow for greater chances of flash flooding. A slight risk excessive rainfall is in effect from eastern Missouri to southwestern Pennsylvania/West Virginia and from southern New York to far southern Maryland to reflect these conditions. The heavy rain and severe weather threats shift a bit to the south on Monday to encompass portions of eastern South Dakota, southern Minnesota and northern Iowa where slight risks of excessive rainfall and severe thunderstorms are in effect.

The Storm Prediction Center cited concerns for hail and a potential tornado in South Dakota and the Upper Mississippi Valley, while severe wind potential and isolated marginal hail are possible over portions of Montana and the western Dakotas. Monsoonal moisture continues to work it's way into the Southwest where marginal risk (at least 5% chance) of excessive rainfall areas are in effect for the next several days. Extreme heat is expected to intensify across much of the Southeast and Tennessee Valley Sunday, with the most dangerous combination of high temperatures and humidity occurring from Monday through Wednesday.

This will lead to a prolonged and extremely hazardous heat wave. Heat levels will become dangerous for anyone without adequate cooling or hydration. High temperatures will soar into the upper 90s to low 100s, with heat index values ("feels like" temperatures) surpassing 110-115 degrees. Several major metropolitan areas--including Raleigh, Charlotte, Nashville and Orlando--are expected to face Extreme HeatRisk for multiple days, with over 20 million people impacted at the peak.