A slow-moving storm system brought heavy rain across a wide section of New York State on Sunday evening, flooding streets, prompting dozens of rescues for drivers whose vehicles were stranded on inundated roads and causing at least one death, the authorities said.
The Hudson Valley was the most affected by the storm system on Sunday, with sections of the area getting between five and eight inches of rain, the National Weather Service said.
The epicenter of the storm struck West Point, the U.S. Military Academy in Orange County, which had about eight inches of rain as of Sunday night.
Trooper Steven V. Nevel of the New York State Police described the search-and-rescue efforts on Sunday night as an “all hands on deck” endeavor, saying that several bridges had collapsed and many roads were impassable.
Trooper Nevel added that parts of the Palisades Interstate Parkway, which is typically heavily traveled, were flooded and completely washed out.
Steven M. Neuhaus, the Orange County executive, said that there had been one death related to the flooding.
State Senator James Skoufis, who represents Orange County, said that the victim was a woman in her 30s, though neither official had details on the cause of death or circumstances.
Gov. Kathy Hochul said on Sunday night that there were additional “missing individuals” in Orange County, saying that in one instance a house had been swept away into a stream. She declared a state of emergency for Orange and Ontario Counties on Sunday night.
“The amount of water is extraordinary,” she said.
Mr. Neuhaus said that there had been multiple calls for water rescues in the vicinity of West Point and Highland Falls, both of which are on the western shores of the Hudson River.
Mr. Skoufis, who was in Orange County on Sunday evening, said that in Woodbury the two major arteries in and out of town were washed out.
“If you’re traveling within Orange County, good luck,” the senator said. “Getting around is next to impossible right now.”
County officials, police departments and other agencies were fielding dozens of emergency calls prompted by flooding that the Weather Service described as “life-threatening.”
Flash flood emergencies — which indicates not only that flooding is occurring, but that it is posing a severe threat to human life — were issued for stretches of the state. Flash flood warnings were also in effect for Manhattan, the Bronx, Queens, Westchester, Clinton and Franklin Counties on Sunday night. A flood watch was also in effect across New York City until 6 a.m. Monday.
Michael Strauss, who lives in Rockland County, was driving home from Hunter Mountain when a heavy downpour began, with rain “pouring off the cliffs and across the roads.”
Mr. Strauss and his wife continued driving through the hazardous conditions, but around a mile north of the Bear Mountain Bridge on Route 9W, they got stuck. They tried various roads but came up against closures and flooding each time.
“We were kind of stuck in an endless loop for five or six hours with no way to go,” Mr. Strauss said. “We’ve been sitting in the car for two hours not moving.”
Additional rainfall and flooding were expected in the Hudson Valley overnight, prompting some towns to declare states of emergency. Mr. Skoufis said that if that prediction holds, “It’s probably going to get worse.”
In Saratoga County, near the town of Waterford, Routes 4 and 32 were flooded with up to two feet of water, Andrei Evbuoma, a meteorologist with the Weather Service in Albany, said.
Portions of nearby roads in the area were impassible, he added, complicating rescue efforts.
Alan C. Mack, the deputy commissioner of emergency management in Orange County, said on Sunday evening that officials were still trying to get a full assessment of the possible damage.
“We’ve got to the point where we know there are people in trouble, and we can’t get to them because the roads are all blocked,” Mr. Mack said, adding that he did not know how many people were stuck.
In Cornwall, a town in Orange County, the local office of emergency management urged residents on Sunday night to “get to higher ground” if their location was not safe. “Travel is impossible,” the office said on Twitter.
Mudslides, stranded vehicles and flooded roadways were reported in town, according to the office.
A New York City-bound Amtrak train was halted as it approached Poughkeepsie on Sunday evening, with an Amtrak employee announcing that there had been a “complete washout of both tracks” south of the city, preventing any travel by train.
The train was put in reverse so it could travel back to Rhinecliff, N.Y., where Amtrak officials were determining what to do with the passengers.
Oliver Mackson, who lives in Poughkeepsie, said he was heading home from Yankee Stadium by train when passengers were told that the ballast had been washed out of the tracks north of the Croton-Harmon station, about 35 miles south of Poughkeepsie.
“Everybody is being pretty subdued,” Mr. Mackson said of the passengers on the train. “It’s very jarring,” he added.
Flooding is a complex phenomenon with many causes, including land development and ground conditions.
Although linking climate change to a single flood event requires extensive scientific analysis, climate change — which is already causing heavier rainfall in many storms — is an increasingly important part of the mix.
Nicholas Bogel-Burroughs contributed reporting.