A powerful nor'easter with 40 million Americans in its path has finally smashed into the East Coast on Friday night, knocking out power for more than 50,000 and partially suspending commuter trains. 

Strong winds have already hit the Tri-State area, with residents experiencing 40mph winds, with gusts up to 60mph. Areas like Long Island and coastal communities could experience higher gusts up to 70mph overnight into Sunday. 

New York City Mayor Zohran Mamdani told residents in a statement on Friday to prepare for 'more rain and stronger winds.' 

'If you're traveling this weekend, give yourself extra time, check your train, ferry or flight before you head out and stay off low-lying coastal roads around high tide,' he said in a statement. 

'If you live in a basement apartment, know your way out and be ready to move to a higher floor if conditions become dangerous. Look out for your neighbors.' 

At least two Long Island Rail Road lines, Valley Stream and Long Beach, have been partially suspended due to flooding near Island Park, as of Saturday morning, according to PIX 11.  

Roughly 22,000 city dwellers are without power, including 11,000 in Suffolk County and 4,000 in Nassau County. 

Around 30,000 people in New Jersey are also without power.  

The first dramatic impacts began unfolding after dark on Friday, with roads transformed into rivers from New Jersey to Maryland while raging surf crashed ashore in Rhode Island.

Thousands of customers were without power and hundreds of flights had been canceled as the sprawling storm began battering the coastline. 

Forecasters are warning some of the worst conditions are still to come.

The harvest moon could also make the flood worse, as the elevated tides will collide with the nor'easter, which could create dangerous coastal flooding, Fox Weather said. The full moon will reach peak illumination at 12.49pm on Saturday. 

A State of Emergency is in effect for New York City, coastal areas of New Jersey, Long Island, and Westchester County, New York, ahead of the strengthening and approaching storm.  

In Narragansett, Rhode Island, dramatic footage showed coastal flooding already underway around Narragansett Pier on Friday. 

Seawater could be seen rushing over the seawall and spilling onto Ocean Drive, while pounding surf reached the Narragansett Town Beach parking lot inundating it.