On Tuesday, July 21, a strong thunderstorm system swept through the Northeast and Mid-Atlantic regions along the I-95 corridor in the United States. The Storm Prediction Center (SPC) issued a tornado warning for cities including New York City and Philadelphia, affecting over 32 million people. The threat was expected to diminish by 9 p.m. that evening.
According to data from the Storm Prediction Center, the tornado warning covered parts of Pennsylvania, New York, New Jersey, Delaware, and Connecticut, including major cities like New York City, Philadelphia, Newark (New Jersey), and Bridgeport (Connecticut). A tornado watch, also known as a Tornado Watch, was issued for the affected areas.
The first round of storms already triggered multiple tornadoes in some areas, with two tornadoes confirmed in northern New Jersey. The severe weather threat was expected to persist into late Tuesday night.
New York City issued a flash flood warning on Tuesday for the entire city. Local authorities reminded residents to ensure they have activated various severe weather alert systems, and to head to designated shelters immediately upon receiving tornado warnings in their area.
The Storm Prediction Center noted that current atmospheric conditions were conducive to the rapid formation of severe thunderstorms, potentially bringing tornadoes, destructive wind gusts of up to 70 miles per hour, and large hail. If multiple storms converge to form a squall line, wind gust intensity could further increase.
From the nation’s capital Washington D.C. to New York City along Interstate 95, the evening commute period from 5 p.m. to 9 p.m. on Tuesday was expected to experience the most significant impact from the storms.
Additionally, some regions of the Appalachian Mountains could see hail and isolated tornadoes. Intense short-duration rainfall could trigger flash flooding, especially in areas experiencing repeated thunderstorms over a short period. Strong gusts of wind could also affect transportation and buildings in major cities.