A volatile summer weather pattern is producing another widespread severe weather outbreak across the eastern United States, where millions of people face threats ranging from destructive wind gusts and large hail to tornadoes and dangerous flash flooding.
The Storm Prediction Center (SPC) has placed a broad corridor from the Ohio Valley into the Mid-Atlantic and Northeast under an Enhanced Risk (Level 3 of 5) for severe thunderstorms on Tuesday, following Monday’s severe weather across the Upper Midwest and Great Lakes. The greatest threat extends from southern Indiana and northeast Kentucky through southern and eastern Ohio, West Virginia, northern Virginia, Maryland, Pennsylvania and into parts of New Jersey.
The outbreak is being fueled by an approaching cold front interacting with exceptionally hot, humid air. Afternoon temperatures well into the 90s Fahrenheit combined with dew points in the 70s are creating an unstable atmosphere capable of producing organized lines of severe thunderstorms.
Forecasters warn the strongest storms may produce widespread damaging wind gusts reaching 70 mph (113 km/h), large hail and several tornadoes. At the same time, abundant tropical moisture will allow storms to generate rainfall rates exceeding 1 inch (25 mm) per hour, raising the risk of dangerous flash flooding, especially across urban areas and locations that were soaked by heavy rain just days ago.
Extreme heat remains another significant hazard. Heat advisories stretch from the Dakotas to the Gulf Coast, with heat index values expected to reach 105°F (41°C) or higher. Parts of western Kentucky remain under an Extreme Heat Warning, where feels-like temperatures could approach 110°F (43°C) before thunderstorms develop later in the day.
Across the Mid-Atlantic and Northeast, forecasters expect several rounds of thunderstorms from Tuesday afternoon into the evening as storms track east from the Ohio Valley.
The National Weather Service issued a Tornado Watch covering much of the Philadelphia metropolitan region until 9 p.m. EDT, including southeastern Pennsylvania, northern Delaware and large portions of New Jersey. A broader tornado watch also extends from Delaware through Philadelphia and New York City into parts of upstate New York.
Multiple tornado warnings were issued across New Jersey during the afternoon, while at least two tornadoes were reported, one in northeastern Pennsylvania and another in northwestern New Jersey. Earlier in the event, at least four tornadoes were also reported in central Wisconsin as Monday’s severe weather swept across the Upper Midwest.
Forecasters say communities along the Interstate 95 corridor may experience two rounds of storms, with an initial batch during the afternoon followed by a more intense line between roughly 5 p.m. and 8 p.m. EDT.
Flash flooding poses one of the greatest concerns. Flood Watches remain in effect from Delaware into southern New York, with the highest risk stretching from Philadelphia through New York City into Connecticut. Repeated downpours over the same locations could quickly overwhelm drainage systems, particularly in densely populated urban areas.
New York City, which experienced widespread flooding over the weekend, remains especially vulnerable. Mayor Zohran Mamdani urged residents to avoid travel during severe weather and advised those living in basement apartments to be prepared to move to higher floors if flooding develops.
Travel disruptions are already mounting as the storms spread eastward. More than 1,900 flights have been canceled Tuesday, with the greatest impacts at airports serving New York City, Philadelphia and Washington, D.C. Ground stops were also implemented at airports in New York City, Boston, Baltimore and Washington.
Farther west, the severe weather has already produced widespread flooding and wind damage across the Tri-State region of Ohio, Kentucky and Indiana, only four days after another major flooding event inundated homes and businesses.
TORNADO WATCH
— Cecily Tynan (@CecilyTynan) July 21, 2026
For the entire area except Kent County until 9pm. Conditions are favorable for storms to rotate this afternoon/early evening. Have a way to receive warnings and stay weather aware. pic.twitter.com/vhV3VLn2nK
The National Weather Service issued tornado warnings Tuesday afternoon for parts of Clermont and Brown counties in Ohio and Owen, Grant, Gallatin and Carroll counties in Kentucky after radar detected rotating thunderstorms capable of producing tornadoes.
Tornado near Hammersville, OH earlier taken from a family friend. #ohwx @NWSILN @KevinWLWT pic.twitter.com/dBGtXvDQ65
— Floogs (@SpenceFluegelWX) July 21, 2026
Communities across the region reported numerous downed trees, flooded roads and wind damage. A cattle trailer was overturned near Hamersville, Ohio, while flooding closed portions of Interstate 71 near Cincinnati after heavy rainfall produced significant ponding. Emergency crews also responded to flooded streets, stranded vehicles and storm damage throughout the area.
Heavy rain also caused dangerous flooding in Des Moines, Iowa, Monday night, where nearly two dozen vehicles became stranded and emergency responders rescued five people from floodwaters.
The severe weather threat will gradually shift toward the Atlantic coast Tuesday night before weakening overnight. However, forecasters warn that oppressive heat will continue across much of the eastern United States through midweek, while the lingering frontal boundary may spark additional rounds of thunderstorms over the coming days.
Residents across the affected regions are urged to closely monitor forecasts and be prepared to act immediately if severe thunderstorm, tornado or flash flood warnings are issued.
