A brutal heatwave that gripped the central and eastern United States is receding, but its departure is ushering in a period of severe weather. The transition from intense heat to cooler temperatures will be marked by powerful storms, lightning, and torrential rain, particularly affecting regions from the Midwest to the Northeast. Some areas, like those northwest of Des Moines, Iowa, have already seen over 9 inches of rain in 24 hours, while suburbs west of Chicago received 4 inches.
The AccuWeather Local StormMax™ for rainfall is projected to be 6 inches, with a general 1-4 inches expected along the Interstate 80 and 90 corridors. The atmosphere, loaded with moisture, will release it as the heat dome collapses, leading to flash flooding. Thunderstorms are also anticipated to be gusty with damaging winds, and frequent lightning is a concern due to the high heat and vigorous storm potential. People are advised to avoid driving through flooded roads and exercise caution when camping near streams.
Several areas are under a severe weather forecast into Friday night, including a zone from northern Mississippi and Alabama to New York and much of Vermont and New Hampshire, with an AccuWeather Local StormMax™ wind gust of 85 mph. A more concentrated zone of severe storms is expected from central Nebraska and southeastern South Dakota to central Iowa and northwestern Missouri, and another pocket in southern Michigan. On Saturday, a heavily populated zone along I-95 in the Northeast, including New York City, Philadelphia, Baltimore, and Washington, D.C., faces a severe thunderstorm risk with an AccuWeather Local StormMax™ gust of 80 mph. Further severe weather is forecast for Monday, extending from Pittsburgh to Virginia Beach, Virginia, and Greenville, North Carolina, with an 80 mph AccuWeather Local StormMax™ gust.
The extreme heat has already disrupted numerous Fourth of July celebrations, leading to cancellations such as Philadelphia's Salute to Independence Semiquincentennial Parade and the temporary closure of the Great American State Fair in Washington, D.C., where 44 people were treated for heat-related illnesses. Over 165 million people were under record temperatures, with the heat index reaching 113 degrees in D.C. on Friday and 112 degrees in Philadelphia. The severe weather could further impact outdoor events, including fireworks displays, and even World Cup matches scheduled in Philadelphia, where a lightning strike within 8 miles of the stadium could cause play suspension.
