Authorities in Delaware said there is “significant damage” throughout parts of the city of Dover after a “likely” tornado touched down Thursday evening, including numerous downed trees, flooding and other damage.
The Dover Police Department, in a social media post, said a state of emergency was in effect and asked the public to stay off the roads.
Earlier, the National Weather Service issued a tornado warning for the Dover area, warning of a confirmed large and dangerous tornado on the ground.
A woman runs through Times Square during a severe rainstorm in New York City, U.S., August 20, 2026.
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It came amid a wave of severe weather that slammed parts of the Interstate 95 corridor during the Thursday evening rush hour, with thunderstorms and dangerous flash flooding
There was a significant risk for flash flooding in New York City, where rain inundated some roadways and subway stations, leading to delays, as well as Philadelphia. Overall, there was the potential for rainfall rates of 2 to 3 inches per hour and 3 to 7 inches of rain in just a matter of hours.
Rain leaks into the Penn Station Subway Station during a severe rain storm in New York, U.S., August 20, 2026.
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On Long Island, in New York’s Nassau County, a possible tornado damaged or destroyed dozens of cabanas at an Atlantic Beach club, according to local authorities.
The Inwood Fire Department was called to the Sun n Surf Beach Club at 2191 Bay Boulevard at about 7:12 p.m. for reports of severe wind damage from what authorities initially described as a possible tornado.
Arriving firefighters found approximately 30 one-story cabanas damaged or destroyed, with the destruction appearing consistent with a possible tornado touchdown, according to Nassau County fire officials.
One beach club worker was reported injured but declined medical attention. No other civilian or first responder injuries were reported.
Search teams were mobilized to ensure no one was trapped inside damaged cabanas.
Nassau County Executive Bruce Blakeman declared a state of emergency.
In Pennsylvania, Gov. Josh Shapiro said state emergency management officials were tracking reports of tornadoes and “significant damage in York and Lancaster counties.”
Flight cancellations began piling up at Northeast airports, with more than 700 flights canceled as of about 6:30 p.m.
People walk through the rain in the Dumbo neighborhood in Brooklyn as severe storms move through the New York area on July 21, 2026 in New York City.
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Flash flooding was possible from Virginia up to Connecticut. A flood watch was in effect from Philadelphia to New York City until 2 a.m. Friday.
ABC News’ Jason Volack contributed to this report.