Hundreds of flights across the U.S. have been canceled and thousands more delayed as a Nor'easter storm drenched the East Coast.

The storm rampaged through the Southeastern states over the weekend and has since pushed north along the coast, bringing heavy rainfall, wind gusts, and power outages from Virginia to Maine.

As of Monday morning, more than 500 flights had been canceled and nearly 16,000 were delayed. Boston's Logan Airport and New York's LaGuardia Airport were most affected by the inclement weather, according to FlightAware.

More than 40,000 customers across New York, Connecticut, New Jersey, Massachusetts and North Carolina have reported losing power.

Several governors have declared states of emergency. Rain showers, wind gusts -- which could reach up to 40 miles per hour in New England -- and "astronomical tides" pose a risk of coastal flooding and beach erosion, according to the Weather Prediction Center.

"This storm may create some of the highest tides that the Northeast has seen in more than a decade. Some beaches may be completely underwater as this storm passes off the coast. This storm may not have a name, but it is causing some serious problems and disruptions along the coast," AccuWeather Lead Hurricane Expert Alex DaSilva said in a statement Monday morning.

Forecasters predict the storm will move northeastward along the Mid-Atlantic Coast on Monday before heading east over the Atlantic Ocean by Tuesday, when the rain will taper off.

New York Governor Kathy Hochul declared a state of emergency for New York City, Long Island and Westchester on Sunday evening due to the storm.

"We're ready to assist local partners as damaging winds & heavy rain move in, with the potential for flooding & power outages," Hochul wrote on X. "Stay vigilant & take steps now to prepare."

A coastal flooding warning is in effect as the state could see winds of up to 55 miles per hour and one to two inches of heavy rain by Monday evening, the New York Division of Homeland Security & Emergency Services warned.

More than 12,000 people were without power as of Monday morning, according to PowerOutage.us. Given the gusty winds, the division warned residents with above-ground power lines should expect to lose electricity, noting that the state is responding. At least 169 trees fell in New York City, including eight that fell on buildings, Pix11 reported.

The annual Columbus Day Parade in New York City, scheduled for Monday, was canceled due to the Nor'easter, officials announced. The parade will not be rescheduled.

New Jersey Governor Phil Murphy declared a state of emergency on Saturday night in anticipation of the storm.

"Monitor your local weather forecasts and warnings and please remain off the roads unless absolutely necessary," Lieutenant Governor Tahesha Way urged in an X post.

More than 6,000 people in the state reported being without power on Monday morning.

NJ Transit, the state-owned public transportation system, announced parts of its rail service were suspended while some bus routes were suspended or detoured "out of an abundance of caution and concern for the safety of our customers and employees, and to protect NJ TRANSIT equipment."

Forecasters warned of moderate tidal flooding, which could damage roadways and lead to beach erosion, as well as gale-force winds, which could knock over trees and cause 12-18-foot waves.

Social media videos and photos captured flooded streets, howling winds and massive waves along the Jersey Shore.

Over the weekend, North Carolina's Outer Banks was hammered by intense waves and heavy rainfall. Parts of state highway NC 12 were closed off and some ferry routes suspended due to "ocean overwash," according to state officials.

At least eight beachfront homes collapsed due to the powerful nor'easter, Fox Weather reported, while footage shows other homes appear to be on the brink of collapse.

Travel chaos as airports cancel flights and more than 100 million face brunt of Nor'easter drenching the East Coast