What to KnowA FIRST ALERT for heavy rain and severe storms, tornadoes was in effect until 9 p.m. on Thursday, Aug. 20. A tornado watch was issued for parts of Delaware, New Jersey, Pennsylvania and Virginia until 10 p.m., according to the National Weather Service.Heavy rain and multiple rounds of sh owers and thunderstorms led to flash flooding.Officials confirmed that a tornado touched down in Dover, Delaware. Overall, the Philadelphia region saw at least eight tornado warnings. Severe storms brought a flash flood threat, damaging winds and possible isolated tornadoes to the Philadelphia region on Thursday, Aug. 20, 2026. Get the latest weather updates by downloading the NBC10 app and following the NBC10 First Alert Weather team. ...read more read less