Powerful Northeast storm knocks out power to tens of thousands and forces water rescues: VIDEO

Updated: 18 DEC 23 10:34 ET

By Elizabeth Wolfe, Robert Shackelford and Mary Gilbert, CNN

(CNN) — Power outages were climbing Monday morning in the Northeast as an intense storm pounded the region with flooding rainfall and strong winds.

Heavy rain and widespread wind gusts of 40 to 50 mph combined to knock out power for more than 450,000 customers from Virginia to New England, according to poweroutage.us. Outages topped 100,000 in both Massachusetts and Maine early Monday.

Power outages are likely to rise throughout the morning as strong winds continue and restoration will be difficult with gusty winds expected throughout Monday.

Get up to speed:

Happening now: Heavy rain is triggering flash flooding from Pennsylvania and New Jersey into New York and southern New England. Widespread wind gusts of 40 to 50 mph stretch from New York City to Maine.
Wind: Winds will continue to be strong across areas near the coast from New York through southern New England into Monday afternoon. Breezy conditions will persist in these areas Monday afternoon, but the strongest winds will shift into Maine by Monday afternoon and continue into Monday night.
Heavy rain: The heaviest rain will wind down across New Jersey, Pennsylvania and New York by Monday afternoon, but will continue for much of the day across New England.
Coastal flooding: Coastal flood alerts stretch from the mid-Atlantic through the Northeast. Powerful winds are driving water ashore and significant coastal flooding is possible in some areas.

A dangerous morning commute is unfolding across the Northeast with water rescues of drivers stranded in floodwaters reported in the region. Flood alerts now stretch from Maryland to Maine, with parts of several states under warnings for dangerous flash flooding.

“Numerous roads” in Danbury, Connecticut, were flooded on Monday morning, forcing the rescue of at least four people, city and fire officials said. No one was injured.

The flash flood risk is increasing in other parts of New England. Parts of New Hampshire and Maine on Monday were upgraded to a Level 3 out of 4 risk of excessive rainfall by the Weather Prediction Center.

Minor to moderate urban flooding could also inundate parts of New York, New Jersey and Connecticut, particularly in areas with poor drainage, the National Weather Service in New York City said. The risk is especially high for low-lying housing such as first floors, basements and underground residences, it said.

Significant coastal flooding is also possible in southern New England, where waterways in some parts of Rhode Island may rise to a level not seen in more than 30 years.

More than 15 million people from the Carolinas to Maine were under high wind warnings on Monday morning. The National Weather Service warned strong gusts may make travel particularly difficult in parts of southern Connecticut, southeastern New York and Boston.

More than 400 flights in the US were cancelled and over 1,400 were delayed on Monday morning, according to FlightAware.com. Wind triggered a ground stop at Boston’s Logan International Airport Monday morning along with delays of over an hour. Additional flight issues are likely to unfold into Monday night.

In addition to disrupting air travel, strong gusts may down trees and power lines, as well as damage or blow away outdoor holiday decorations in parts of the region, officials have warned.

The storm system will start to push away from the Northeast later Monday evening, but its effects will likely linger, the weather service said.

“Even though the big storm will begin to depart the Northeast Monday evening, the huge circulation of the storm will overspread the entire eastern U.S. with very blustery conditions,” the weather service said.

Damaging flooding hits the Southeast

The storm began trekking up the coast on Saturday, sweeping through much of Florida and then skirting the Southeast and mid-Atlantic coasts on Sunday, battering coastal communities with powerful winds and at times record-breaking rainfall.

A flash flood emergency was issued Sunday in South Carolina’s eastern Georgetown County, just south of Myrtle Beach, after nearly a foot of rain fell there in just a few hours.

The surge of floodwater forced water rescues across the area, the National Weather Service said. The weather service in the region said it has also received reports of snapped power poles, trees fallen on homes and damaged buildings in the area from a potential tornado.

Several daily records for rain were set in South Carolina, including 3.86 inches in downtown Charleston, where the last record of 1.18 inches was set in 1923.

The record rain combined with strong winds pushing water onshore to cause widespread flooding issues in Charleston on Sunday. High tide at one reporting station in Charleston climbed to the highest level ever recorded from a non-tropical system.

Rainfall totals also climbed in Florida. Gainesville recorded 7.29 inches from the storm and Jacksonville received 5.70 inches.

Strong wind gusts of more than 50 mph also battered the state on Sunday. Wind gusts roared to 61 mph in West Palm Beach.

CNN’s Sara Tonks Nouran Salahieh, Caroll Alvarado and Celina Tebor contributed to this report.