Heavy rain and strong winds battered the northeastern United States on Saturday as an unusually powerful autumn storm intensified, leaving tens of thousands without power and US media reporting one person dead.

New York, Boston and Philadelphia were all in the firing line of the “Nor’easter” — so labeled for its northeasterly winds — as authorities warned of potential major flooding and road closures.

The storm continued to dump rain during its “churn off the coast of the northern Mid-Atlantic and southern New England Saturday afternoon,” the National Weather Service said in its latest forecast.

The storm was expected to move toward New Jersey and Long Island “through tonight, resulting in the full force of this Nor’easter” impacting the region by Sunday morning, forecasters said.

Additionally, “major coastal flooding is expected along the Mid-Atlantic Coast over multiple high tide cycles coming off a full moon through the weekend,” NWS said.

New York state Governor Kathy Hochul said the storm was bearing down Saturday on coastal areas of New York City and Long Island.

“Conditions are extremely dangerous. Anyone who goes in or near the water this weekend is literally gambling with their life,” Hochul said in a press briefing.

In Brooklyn, a 56-year-old man was killed when winds toppled a tree that struck him, US media reported.

More than 60,000 customers in New York, New Jersey, Connecticut, Massachusetts, Rhode Island and Pennsylvania were without power as of 6:00 pm (0100 GMT) Saturday, according to the monitoring tool poweroutage.com.

Up to six inches (15 centimeters) of rain expected on Long Island over the next few days.

“We expect waves as tall as 20 feet (six meters) in some areas,” Hochul said.

New York City Mayor Zohran Mamdani warned residents of the country’s most populated city about strong wind gusts and the possibility of downed power lines, saying “Don’t travel if you don’t have to.”

The storm forced the cancellation of hundreds of flights early Saturday, with 253 at Boston’s Logan airport alone, and ongoing delays were reported across the region, according to tracker Flight Aware.

Major airlines including JetBlue, United and American issued travel alerts allowing passengers to change their flights without incurring fees.

The United Nations, where world leaders are gathered for the organization’s General Assembly, urged media outlets covering the event to clear broadcasting equipment from outside the New York headquarters due to strong winds.

Safety has to come first

Major cultural events were also called off, including the Global Citizen and All Things Go festivals in New York, and Oceans Calling in Maryland.

“Safety has to come first. This is the first time in 14 years we’ve had to cancel,” said organizers of the Global Citizen event in Central Park, which was meant to feature Lenny Kravitz, Lauryn Hill, Alicia Keys and country stars Lainey Wilson and Shaboozey.

About five inches of rain was forecast in areas of Massachusetts including Boston — the equivalent of more than a month’s worth of rainfall.

After much uproar surrounding his tour, British pop singer Ed Sheeran’s weekend concerts near Boston were canceled due to the storm, which had whipped up wind gusts of 70 miles (113 kilometers) per hour along the New England coast.

Some coastal areas of North Carolina, Virginia, Maryland, Delaware and New Jersey have already seen flooding this week.

Nor’easters can occur throughout the year but are more frequent between fall and early spring. They are almost always accompanied by heavy rain or snowfall, as well as strong wind gusts.

Earlier this year, a Nor’easter that pummeled the northeast disrupted hundreds of flights and left thousands of homes and businesses without power.

That storm came weeks after the region recovered from a devastating winter weather system that was linked to more than 100 deaths.