Almost the entire East Coast and Southeast — 84 million people in all — were at risk for severe weather through Tuesday night.
The risk zone outlined by the National Weather Service stretched from the Louisiana-Texas state line east to Atlanta and up the coast to Boston.
"We're going to have a lot of spots across the Mid-Atlantic that are under the gun for severe weather" by the end of the day, said Danielle Banks, a meteorologist for The Weather Channel.
Banks said parts of the Northeast, including the New York area, through New England could get as much as 2 inches of rain, accompanied in places by spotty hail and damaging winds. The National Weather Service said the threat of heavy showers would extend through the evening into early Wednesday.
The rain started Tuesday morning in Washington, Philadelphia and New York, making for a messy commute. By late Tuesday afternoon, flights into John F. Kennedy International Airport were delayed by almost four three hours, with delays of about two hours at LaGuardia and Newark, New Jersey, and an hour in Boston, according to the Federal Aviation Administration.
Some of the storms could produce damaging wind and flash floods. The Weather Channel reported that a tornado couldn't be ruled out in New England. Parts of North Carolina and the Richmond, Virginia, area were briefly under tornado warnings Tuesday afternoon as wind and rain tore through. No twisters were confirmed to have touched down, and no damage was reported.
The storms sent temperatures plummeting over some areas. Tuesday morning, Lake Charles, Louisiana, set a record at 102 degrees. By late in the afternoon, after the wind and rain moved through, it was just 78 degrees, the National Weather Service said.
The temperature in Houston, meanwhile, plummeted 31 degrees in just a few hours — from a record 104 in the afternoon to 73 at 7:30 p.m. (8:30 p.m. ET) — as intense thunderstorms lashed southeastern Texas, including Galveston, accompanied by 60-mph winds and the threat of damaging hail and flash floods.
About 77,600 customers were without power Tuesday night, CenterPoint Energy said, down from 112,000 earlier in the evening.
On Wednesday, the severe weather threat should be confined to the Southeast, the Rockies and the Southwest, according to The Weather Channel.