Nearly 50 million Americans are bracing for severe thunderstorms that could sweep across the Northeast within hours, bringing the risk of damaging winds, flash flooding, hail and possible tornadoes in several states.
The National Weather Service said 17 states are in the storm’s potential path, with New York, New Jersey, Pennsylvania, Maryland, Delaware, Virginia, West Virginia and Ohio among the areas under threat.
The severe weather is expected to intensify Tuesday afternoon, with forecasters warning of flash flooding, large hail and wind gusts that could reach 75mph in major population centers including New York City, Philadelphia, Baltimore, Pittsburgh and Washington, DC.
Farther south and west, North Carolina, Tennessee, Kentucky and parts of Arkansas, Missouri, Illinois, Indiana, Connecticut and Massachusetts could also see dangerous storms develop Tuesday night.
The NWS also cautioned that there is a limited chance some storms could strengthen into supercells, a rare but powerful type of thunderstorm capable of spawning tornadoes, uprooting trees and ripping roofs from buildings.
According to the NWS Storm Prediction Center, there is a five percent risk of a tornado touching down Tuesday night within a corridor stretching from Kentucky to New York, an area home to 57 million people.
AccuWeather Expert Meteorologist Tyler Roys said in a statement: ‘While tornadoes can’t be ruled out, the bigger threat today is damaging straight-line winds as lines of storms sweeps through the region.’
‘In a densely populated corridor like this, that kind of wind can down trees and power lines fast and it’s timing up with the evening commute, which is exactly when we don’t want people caught off guard.’
A storm that may produce tornadoes near the New York City area (Pictured) is expected to impact millions starting Tuesday afternoon
The National Weather Service has warned of severe thunderstorms affecting 50 million people on Tuesday
Potentially deadly flash flooding is expected to cause major travel disruptions along the entire East Coast on Tuesday and Wednesday, with the heaviest flooding expected to span from the New York City area to North Carolina.
New York City’s Department of Emergency Management has warned residents to expect the worst of the storm between 6pm and 11pm ET.
New York’s John F Kennedy and LaGuardia Airports have both issued ground stops due to impending thunderstorms, delaying travelers by more than two hours.
AccuWeather meteorologists expect the storm to have its biggest impact on the evening commute for millions of Americans tonight.
Heavy showers and thunderstorms will increase the risk of localized flash flooding, especially in urban areas where drains are unable to handle that amount of water pouring down, sometimes in just a matter of minutes.
This often catches people by surprise with little or no warning to get to safety. Forecasters have warned that this makes flash flooding one of the most dangerous types of flooding.
NWS officials warned in a statement: ‘Turn around, don’t drown when encountering flooded roads. Most flood deaths occur in vehicles. Be aware of your surroundings and do not drive on flooded roads.’
No official tornado watches or warnings have been issued in the Northeast as of 12pm ET.
Flash flooding and travel disruptions are expected to impact millions across the US East Coast
A tornado touches down in Indiana in March 2026 during a major thunderstorm (Stock Image)
There is a slight risk of tornadoes across mover ten states on July 21
AccuWeather revealed that the major storm event formed after a large cold front pushed eastward across the US and crashed into very warm and humid air lingering after a massive heat dome blanketed the region earlier in the month.
When cooler air clashes with this hot, moist air, it forces the warm air to rise quickly – creating powerful thunderstorms.
Cities with large public transportation systems, such as New York and New Jersey, have already warned that subways could be flooded during the heavy downpours Tuesday evening.
Newark, New Jersey’s Office of Emergency Management has begun placing storm barricades in areas where flooding is expected.
Residents in Connecticut and Pennsylvania have already begun reporting afternoon storms sparking flash floods.
Specifically, the National Weather Service’s New York office issued flash flood alerts in Bridgeport, Stamford and Norwalk, Connecticut through 3.30pm ET.
