Approximately 30 million Americans across the Heartland and Northeast are facing a renewed threat of flash flooding as a slow-moving cold front is expected to bring multiple rounds of heavy rainfall through Sunday.
The system follows early-week storms that impacted the Upper Midwest and targets areas, particularly in the Ohio and Tennessee Valleys, where soils are already saturated from late June downpours. The National Weather Service has issued a Level 2 out of 4 flash flood risk for portions of the Mississippi River Valley, including western Kentucky, southern Illinois, and parts of eastern Missouri, for Thursday. This risk is expected to shift eastward by Friday.
Shifting Storms and Elevated Risks
By Friday, the flash flood risk will extend to southwestern Pennsylvania, Ohio, Kentucky, Missouri, Tennessee, and West Virginia, continuing through early Sunday. The FOX Forecast Center has indicated that this threat could be upgraded to a Level 3 out of 4 if storms repeatedly track over the same areas.
The slow-moving nature of the front is a key concern. Persistent winds parallel to the front are anticipated to cause storms to develop and move over the same locations repeatedly, increasing the potential for excessive rainfall. Widespread rainfall totals of 1 to 2 inches are expected across a broad area, with localized amounts potentially exceeding 3 to 5 inches where storms linger. This is particularly concerning for regions like Kentucky, which experienced Flash Flood Emergencies at the end of June.
While the heaviest rainfall is forecast for the Ohio and Tennessee Valleys, scattered showers and thunderstorms are also expected to affect the Northeast through Friday. However, drier conditions are anticipated for the Northeast by Saturday evening and Sunday as high pressure builds in behind the front.
The system is expected to continue its slow southward and eastward progression, meaning flash flood threats could extend into the following week.