CNN  — 

Intense rain and flash flooding that left at least one dead in southeastern New York continued to pelt the Northeast on Monday, forcing residents from their homes and prompting road closures and water rescues.

Over 9 million people are under flood alerts across the Northeast on Monday, including parts of New York, Vermont, Massachusetts and Maine – as well as across the country in Washington and Alaska. Flash flood emergencies and landslides are expected, with heavy rainfall expected throughout the day.

The National Weather Service issued a flash flood emergency warning for central Vermont on Monday, where 19 people have been rescued by boat and 25 others have been evacuated, Vermont’s Urban Search and Rescue team coordinator Mike Cannon told reporters.

Two areas in the state, Weston and South Londonderry, are currently inaccessible due to flooding, and search and rescue teams are working to regain access and perform welfare checks, Cannon said.

Gov. Phil Scott declared a state of emergency Sunday as the weather service warned flash flooding could become “extremely dangerous.”

“My friends, this is the new normal,” New York Gov. Kathy Hochul said, addressing the havoc that the storm is wreaking in the state, where more than 8 inches of rain fell within a 24 hour period in some locations in the state.

A 35-year-old woman died Sunday, swept away by floodwater as she tried to evacuate her Orange County home. The flooding has caused “easily tens of millions of dollars in damage,” county Executive Steve Neuhaus said Monday.

Many residents who tried to drive out of the area, which includes the US Military Academy at West Point, were trapped Sunday, Neuhaus said. “We saw many cars that tried to go for it through the water, didn’t make it, and got stuck,” he said, adding that he saw “active duty Army soldiers up to their bellies … we were walking to cars to make sure people got out.”

Emergency personnel used a boat to rescue residents of flooded homes on Lowland Hill Road in Stony Point, New York,  on Sunday.

In western New York’s Ontario County, door-to-door checks were conducted at about 120 homes, which prompted the voluntary evacuation of more than a dozen individuals and five pets, according to Hochul. Officials in the area have set up a temporary shelter.

Hochul said FEMA and White House officials have offered to assist with the response.

“While the storm has already passed through the southern part of New York, conditions remain dangerous in further north where there are ongoing extreme weather conditions. I urge all New Yorkers to remain vigilant, monitor local forecasts and have an evacuation plan ready if you’re in a danger zone,” Hochul said.

The Red Cross has opened three shelters for people displaced by the flooding: one in Highland Falls, New York; one in Reading, Pennsylvania; and one in Barre, Vermont. On Sunday night, around 25 residents in Pennsylvania and 11 in New York were seeking refuge at the shelters, the Red Cross told CNN.

Once-in-a-millennium rainfall

Rainfall in West Point, New York, totaled more than 7.5 inches in six hours Sunday afternoon, according to preliminary data from the National Oceanic and Atmospheric Administration. That’s a 1-in-1,000 year rainfall event for the area, according to a CNN analysis of NOAA’s historical rainfall frequency data.

A once-in-a-millennium rainfall event is one that is so intense, the chances of it happening in any given year is just 0.1%.

Reading, Pennsylvania, received 5.35 inches of rain Sunday, shattering its old daily rainfall record of 3.47 inches, set in 1952.

Areas across New England could see 3 to 5 inches of rain Monday, which could bring rainfall totals for this storm up to 12 inches.

A moderate risk, Level 3 of 4, of excessive rainfall is in place in New England through early Tuesday. Rainfall totals across the area are expected to range from 3 to 5 inches.

New York could see 1 to 2 inches of rain per hour on Monday, the NWS warned.

In Vermont, the heavy rain has left at least seven people trapped in their homes as of Monday evening, Emergency Management Director for Londonderry Richard Phelan told CNN.

Rescuers cannot reach them due to several road closures, Phelan said, and officials are advising those residents over the phone to get to the highest ground they can in their homes.

Most of the town’s roads are impassable and Londonderry is cut off from the rest of the state, according to Phelan. “It’s the worst we’ve seen in many, many years,” Phelan said.

Numerous rivers across Vermont have been rising as a result of the heavy rainfall, with some rising more than they have since Hurricane Irene in 2011. The rainfall could push isolated storm totals towards 12 inches when combined with rainfall from the weekend, according to the weather service.

The Winooski River at Montpelier swelled above major flood stage Monday and continues to rise quickly. The river has risen nearly 14 feet since early Monday morning and is now expected to crest overnight at 22.7 feet.

“Downtown Montpelier will be inundated, and local roads will be covered by water. Route 2 and railroad tracks along the river will be covered with water,” the National Weather Service said, noting this flood stage would be equivalent to a “1 percent annual chance flood,” or 100-year flood.

The White River in West Hartford has similarly risen 10 feet in 10 hours since Monday morning and is expected to crest above 20 feet for the first time since Irene in 2011.

Nearly a dozen different locations across Vermont from the Connecticut River in the south to the Missisquoi River in the north will experience moderate or major flooding before river levels begin dropping Tuesday.

Emergency personnel tend to a resident in Stony Point, New York, after rescuing the man from his flooded home Sunday.

Officials have made 50 rescues across the state, including using boats to help people trapped in their homes or in cars that were swept away in fast-moving waters.

Windham and Windsor County have been the worst hit by the flooding, according to Cannon, from the state’s Urban Search and Rescue Program.

In a Monday Facebook post, Scott said the state was enacting an “all-hands-on-deck” response to the extreme flooding. “We have not seen rainfall like this since Irene, and in some places, it will surpass even that,” the governor said.

In New York, six counties are under a state of emergency and state officials are scrutinizing roads and bridges to ensure they’re not “structurally compromised,” Gov. Hochul said at a Monday news conference.

New York City’s Emergency Management Department cautioned residents living in basement apartments “to be prepared to move to higher ground.” Heavy rains continuing through Monday morning “may cause rapid flooding to basements with little to no notice and can be life threatening,” an alert from the agency sent Sunday afternoon reads.

When torrential rain from Hurricane Ida caused flooding in New York City in 2021, most of the homes where residents were found dead were illegally converted basement or cellar apartments, city officials said.

“Do not underestimate the power of fast-moving water,” Hochul said. “Two feet of fast-moving flood water will float your car, and water moving at two miles per hour can sweep cars off a road or bridge.”

And in Massachusetts, the towns of Williamsburg, Clarksburg, Deerfield and Becket, as well as the city of North Adams, have all declared emergencies, a spokesperson for the Massachusetts Emergency Management Agency told CNN. Residents should expect rivers, creeks and streams to rise gradually through Tuesday.

Trapped drivers had to swim out of their cars

Two dozen residents were evacuated and two town employees were rescued from flooding Monday in Ludlow, Vermont, where routes in and out of the city were blocked, Ludlow Emergency Management Director Angela Kissell told CNN. “There’s currently debris and water blocking the main roads. We’re an island right now,” Kissell said.

Ten people were rescued from a campground in Andover, Vermont when a bridge at Horseshoe Acres Campground was washed out, leaving campers trapped, said Jeannette Haight, the town clerk and treasurer.

Girl Scouts Heart of the Hudson canceled camp on Monday due to the heavy flooding in Rockland and Orange counties on Sunday.

In the same county, the town of Cornwall issued a “No travel Advisory” Sunday after storms flooded multiple roads, triggered mudslides and forced rescues from stranded cars. In nearby Rockland County, state police also reported “numerous motorists stranded” due to flooding in the area.

Firefighters in Canandaigua in Ontario County, New York, received over 150 water related calls and performed dozens of rescues, Canandaigua Fire officials tweeted Sunday, sharing a photo of people kayaking through deluged streets.

Eastern Pennsylvania also saw “significant” flash flooding Sunday afternoon, according to the weather service. The Fleetwood Police Department shared images of deluged roadways in Berks County and urged residents to avoid all travel, adding that crews were out responding to rescues and flooded basements Sunday.

CNN Meteorologist Brandon Miller and CNN’s Kristina Sgueglia, Polo Sandoval, Michelle Watson, Christina Maxouris, Joe Sutton, Sara Smart, and Zoe Sottile contributed to this report.