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(NEW YORK) — The Interstate 95 corridor from New York City to Washington, D.C., is bracing for dangerous flooding that could overwhelm the region on Thursday.

A level 3 out of 4 threat for flash flooding is in effect in New York City, parts of Long Island, the lower Hudson Valley, southwest Connecticut, New Jersey, Philadelphia, Maryland, and Washington, DC.

Heavy storms could lead to rainfall rates of up to 3 inches per hour. Some of the most intense downpours could drop 2 inches or rain in just 30 minutes.

Widespread rain totals are forecast to be 1 to 3 inches, but the heaviest storms could bring 5 to 8 inches of rain to isolated areas. Damaging winds, lightning and some hail are also possible.

The storms could begin as early as 1 p.m. Some of the heaviest rain may fall during the late afternoon rush hour, and the heavy rain could continue well into the evening.

New York City has issued a travel advisory for Thursday and Friday, with a flood watch beginning Thursday afternoon.

“Be prepared for a serious storm,” Mayor Eric Adams warned on social media on Thursday.

“Avoid traveling if you can, and set up any flood prevention tools in advance,” he said.

New Jersey will be under a state of emergency beginning Thursday afternoon.

“I urge all New Jerseyans to remain alert,” acting Gov. Tahesha Way said in a statement. “Residents should remain off the roads and indoors unless absolutely necessary.”

And in the West, residents of Ruidoso, New Mexico have endured the fourth flash flood event of the month. The Ruidoso Downs Racetrack overflowed and the Rio Ruidoso river at Hollywood crested at 9.4 feet.

More downpours are possible in the area on Thursday night and Friday night.

Meanwhile, more than 50 million Americans across 11 states are under heat alerts as dangerously high temperatures hit the South.

An extreme heat warning remains in effect for the lower Mississippi River Valley on Thursday. Heat indices — what temperature it feels like with humidity — could reach 110 to 120 degrees in Tennessee, Arkansas, Louisiana and Mississippi.

Over the weekend, the Southwest will feel the heat. In Arizona, Phoenix and Tucson are under extreme heat warnings as temperatures without humidity could reach 105 to 114 degrees.

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