After making landfall in southwestern Rhode Island on Sunday afternoon, Tropical Storm Henri moved slowly northwest across the region, weakening quickly but still bringing heavy rain and 50-mile-an-hour winds.
The storm had already left more than 135,000 homes without power from New Jersey to Maine. But heavy rain, strong winds and coastal flooding are expected to continue through Monday, and the National Hurricane Center said it expected the storm to slow further and linger near the border between Connecticut and New York on Sunday night.
There was some risk of tornadoes on Sunday across southern New England, the National Weather Service said.
About three-quarters of the homes in coastal Washington County on Rhode Island, which is home to more than 125,000 people, were already without power Eastern time when the storm made landfall there at 12:15 p.m.
Rainfall ahead of the storm’s landing — a record 4.45 inches fell in Central Park in New York City on Saturday — crippled railroad service on Long Island and in southern New England and forced the cancellation of hundreds of flights on Sunday at the airports serving New York City. Widespread roadway flooding was reported in New York and New Jersey.
Firefighters in Newark, N.J., rescued 86 people, including 16 children, after “significant flooding” submerged multiple vehicles in several areas across the city, according to a statement from Brian O’Hara, the director of Newark’s department of public safety.
After slowing down on Sunday night, the heart of the storm is expected to move east and northeast across Connecticut and southern Massachusetts on Monday, then continue across southern Vermont, New Hampshire and Maine before heading out to sea again.
Forecasts had said that storm surges of up to five feet in some parts of the region. But as of Sunday afternoon, all of the storm surge warnings had been lifted, according to the hurricane center, though there was still the possibility of some localized surges.
Through Monday, three to six inches of rain were expected in New England, southeast New Jersey, northeast Pennsylvania and Long Island and other parts of New York, the hurricane center said. Some pockets could see up to 12 inches.
Tropical Storm Henri cut the power to much of coastal Rhode Island as it made landfall on Sunday, downing utility lines and severing service to more than 80,000 homes, according to the utility National Grid.
In Washington County, home to more than 125,000 people, three-quarters of homes already lacked power as of 12:15 p.m. Eastern time when the storm landed at the town of Westerly.
On Sunday afternoon, state authorities reopened the Newport Pell Bridge, the Jamestown Verrazzano Bridge and the Mount Hope Bridge, after they had been closed for several hours because of high winds.
A ban on motorcycles and tractor-trailers from roadways until further notice remained in place.
“I’m asking you, Rhode Island, to stay home until this storm passes,” Gov. Dan McKee said in a morning news conference. “If you venture out, you are not only putting your own life at risk, you are endangering our first responders.”
Providence’s hurricane barrier was closed Sunday morning, as were vehicle gates designed to keep traffic from roads near the Providence River. It is the first time the vehicle gates have been closed for a storm since Sandy in 2012, according to Clara Decerbo, director of the Providence Emergency Management Agency.
Winds from the tropical storm could near 70 miles an hour — close to the 74-mile-an-hour threshold for a Category 1 hurricane. “Most people that die during storms like these are going to watch the waves at Narragansett, or something like that, and get swept out to sea,” Ms. Decerbo said.
The areas near Providence’s waterfront were quiet Sunday morning except for some joggers, sightseers and a few people fishing.
James Ales and Meghan Sharp came out to see the hurricane barrier, whose gates had shut for the first time since they’d moved to Providence two years ago. They had already prepared for the storm, buying batteries and groceries, and shifting things around in their basement, which floods even in slight rain.
A man fishing on the Providence River, who offered only his first name, Mike, said he planned to stay there “until my wife calls me and says, ‘Get home.’”
In one of his final acts as governor, Andrew M. Cuomo said at a news conference on Sunday that he had declared a state of emergency in New York as Tropical Storm Henri threatened to bring heavy rainfall across the state.
Mr. Cuomo is expected to resign on Monday night, after an investigation by the state attorney general found that he had sexually harassed 11 women.
But even as the state deployed National Guard troops, generators and excavators in preparation for the storm, his replacement, Lt. Gov. Kathy Hochul, who is set to be sworn in on Tuesday morning, was noticeably absent from Sunday’s news conference.
Ms. Hochul has been briefed by the governor’s office on the progress of the storm, two administration officials said, but her team had to request a direct briefing. Ms. Hochul also participated in a call about the storm with Mr. Cuomo and the White House — at the White House’s invitation, not the Cuomo administration’s, a Hochul administration official said.
Mr. Cuomo’s office declined to comment on the nature of the storm briefings. As he was preparing to move out of the Executive Mansion, Ms. Hochul was preparing to move in.
After speaking with Southampton officials on Saturday, she had been planning to attend fund-raisers on Long Island on Sunday, an administration official said. With the storm bearing down, she canceled the fund-raisers and returned to Buffalo on Saturday night to pack up for her move.
Asked why Ms. Hochul was not present at the news conference, Mr. Cuomo said that she had been briefed and that he was in “constant communication” with her. He said that effects of the storm were expected to be over by Monday evening and that state officials “don’t expect any real significant damage post the event.”
“Nothing on the scale of Superstorm Sandy, for example,” he said.
Mr. Cuomo said he had asked emergency management officials who were thinking of stepping down when he resigns to stay on until the storm’s effects pass.
My team and I are continuing to closely monitor #Henri.
The storm has weakened slightly, but that does not mean the risk is gone.
Storm surge, heavy rain and flooding (including inland flooding) remain serious threats.
New Yorkers, please monitor updates & stay safe.
— Kathy Hochul (@ltgovhochulny) August 22, 2021
Henri, downgraded from a hurricane but still packing 60-mile-an-hour winds, made landfall near Westerly, R.I., early Sunday afternoon. Still, storm surges of two to four feet were possible on Sunday along the Atlantic Ocean and Long Island Sound coasts, from Queens in New York City to the tip of Long Island, the National Hurricane Center said.
The emergency declaration meant that the state could use federal funds to prepare. Mr. Cuomo said that rainfall leading into Sunday had already saturated the ground, and that forecasts showed around four to five more inches of rain falling through Monday in the Catskills, Westchester County and Suffolk County.
Mr. Cuomo compared the forecasts to the devastation caused by Hurricane Irene and Tropical Storm Lee, which hit within days of each other in 2011.
“You have hills, you have creeks, the water comes running down those hills, hits what was a creek and turns it into a ravaging river,” he said. “I have seen towns float away.”
Mr. Cuomo said about 500 National Guard troops and 1,000 state police had been deployed around the state in preparation for Henri. Bulldozers were moving sand around the South Shore of Long Island to guard against storm surge.
Dana Rubinstein contributed reporting.
Against gathering winds, the 400-ton steel doors connecting the hurricane barrier in New Bedford, Mass., groaned into place Sunday morning, sealing off the region’s largest fishing port as southern New England braced for the impending storm. The New Bedford Hurricane Barrier hadn’t closed because of a storm since Sandy in 2012.
Those able to make it inside were packed tight, wooden sailboats and lavish yachts jammed beside the rusted fishing vessels more typical of this industrial harbor, bobbing in the nervous swells. Those still at sea were expected to find another port.
“Once it’s closed, it’s closed,” said Justin Poulsen, director of the New Bedford Port Authority. “You can’t underestimate this kind of storm.”
The last vessel to enter the harbor, 22 minutes before the barrier closed, was the Eagle Eye II, a New Bedford swordfish vessel, according to M.L. Baron, who runs a weather website out of neighboring Fairhaven. Tropical Storm Henri was expected to hit New Bedford late Sunday morning or early afternoon.
The New Bedford Port Authority announced that it was at capacity by midday Saturday. Vessels hailing from New Jersey, Rhode Island, New York and Massachusetts were stacked six deep along the docks. Many had cut their trips short.
“You want to be protected when nature turns ugly,” said Walter Ramos, 59, who powered his 55-foot sloop, Beneteau, from the exposed port in Dartmouth to New Bedford.
John Alvernaz, 55, a deckhand on the William Lee, a roughly 75-foot scalloper out of New Bedford, said their crew was about 100 miles offshore Friday afternoon when they felt the winds pick up. They had caught about a quarter of their 18,000 pound quota when the captain made the call to steam back to port.
“A storm like this, we weren’t going to take a chance,” he said.
Nearby, a local shipyard was busy hauling out a double-decker yacht flagged from Newport, R.I. Further down the port, vacationers in bathing suits and carrying luggage streamed off the Seastreak ferry from Martha’s Vineyard, an island about 15 miles southeast.
Hotels in New Bedford were packed as tight as the docks. Weddings that had booked rooms through the weekend were canceled, and fishermen, yacht owners and power-company employees have taken their place.
“We’re New Englanders. This is what we do,” said a clerk at the New Bedford Harbor Hotel. “We buckle down and get through it.”
Mr. Baron, who was on the sea wall on Sunday morning, recalled the sound of sirens, barely audible through the wind, as the gates closed for Hurricane Bob 30 years ago. At least three fishing boats were locked out, forced to weather the storm outside the barrier.
“They were angry,” he said. “But they rode it out — bow to the wind and full throttle.”
Thirty years ago this week, M.L. Baron stocked his van with provisions — deviled ham and two 30-packs of Coors Light — fired up his shoe-box-size cellphone, parked beside the New Bedford, Mass., waterfront and waited for Hurricane Bob.
He went out before dawn, so his bosses couldn’t tell him to stay home. As the winds picked up, the tourists and thrill-seekers thinned out and then disappeared entirely, recalled Mr. Baron, 63, who operates a weather station in Fairhaven, near Cape Cod, and was broadcasting that day over WMBH, an AM radio station.
“The next thing I know, I’m looking out, I go, ‘Jesus, I’m all alone.’ I’m saying to myself, how bad is this going to get?” he recalled. “I say, ‘Well, I made my choice when I got up at 3 in the morning.’”
Peering through the windshield, he could see road signs flopping back and forth, making an unearthly twanging sound; the van began to shake as if there were a crowd around it, trying to tip it over. The wind grew so loud, Mr. Baron said, that he could no longer hear the sounds of crashing debris, and the scene outside was blotted out by bands of rain.
“It’s almost like a paradox; all you can hear is the wind,” he said. “You might as well be in a cocoon.”
Hurricane Bob, in 1991, remains the last hurricane to make landfall in New England. As Henri approached the region as a hurricane before being downgraded to a tropical storm on Sunday morning, memories rushed back.
Bob caused $680 million in damage, knocked out power to hundreds of thousands of households, caused the deaths of more than a dozen people, and altered the coastline of Cape Cod.
Cleanup was a weekslong process. Boats that washed as far as a mile inland had to be hoisted up with helicopters and ferried back and splashed into to the water. There was a strange, sweet smell of splintered trees and foliage baking in the sun. Hordes of yellow jackets and hornets had been driven from their nests. They circulated, angry and stinging.
The winds had ripped apart houses in Mattapoisett, a town on Buzzards Bay, and Mr. Baron remembers coming across people’s possessions scattered in unlikely places as he drove around after the storm. “I had a carved teddy bear the size of a refrigerator in the middle of Causeway Road, bureaus, an actual toilet,” he said.
Mr. Baron, who is now semiretired, said he would monitor Henri from his home on West Island, near New Bedford, from a room that he has fitted with so much equipment that he calls it the “crystal palace.” There will be no beer. (“I grew up a long time ago,” he said.)
But he said that he would monitor it on his website, and that he was looking forward to that stretch of hours or days when everyone’s attention was trained on one thing: the immense power of nature.
“You’d be surprised what you forget when there’s a hurricane overhead,” he said.
It is a new, foreboding normal in low-lying cities coming to grips with climate change: As Tropical Storm Henri approached the New England coast, crews of workers in Boston installed metal posts and aluminum planks around the entrance of the Aquarium subway station to keep floodwaters from cascading down from street level.
The city was jolted in 2018 when freezing runoff from a winter storm gushed down the station’s stairs and forced the Blue Line to close. Flood control has become a focus for Boston’s subway system, which weaves through tidal flats and marshlands and a mile-long underwater tunnel to connect outlying neighborhoods to downtown.
A study published this month in the journal Transportation Research called climate change an “existential threat” to public transit in Boston: Given the expected rate of rising sea waters, an extremely strong storm — one with a 1 percent chance of occurring in a given year — would completely inundate the Blue Line and much of the Red and Orange Line.
A storm of that magnitude in 2070, the researchers found, would flood nearly the whole network, with only 9 percent of passenger trips remaining unaffected.
“In the more severe scenarios, I was frankly surprised at how much of the system was affected,” said Michael Martello, a Massachusetts Institute of Technology researcher and lead author on the report, which was funded by the Massachusetts Bay Transportation Authority.
On Sunday morning, with the storm’s core projected to move into central Massachusetts, it appeared Boston would see high winds but be spared the heaviest rains, receiving one or two inches.
Flooding subways are a visible reminder of the vulnerability of cities to rising sea levels; in July, Tropical Storm Elsa sent floodwaters cascading down subways in northern Manhattan and the Bronx. The same month, a catastrophic flood inundated the subway in Zhengzhou, in central China, leading to the deaths of 12 people, and incredulous commuters in London shared photographs of flooding in the Tube.
Boston, a peninsula enlarged by vast stretches of man-made landfill in the 19th century, is particularly vulnerable to rising waters, activists say.
“Our built environment was built for rainfall patterns of the past, certainly not for what we are seeing now or for what is coming,” said Emily Norton, the executive director of the Charles River Watershed Association, who noted that many of the city’s prestigious medical centers sit atop former wetlands.
“If Sandy had hit Boston during high tide, we would have looked like Katrina,” Ms. Norton said. “Boston is very, very vulnerable, and we’re not acting like it.”
The Hamptons, the group of seaside resort towns on Long Island’s South Fork, had braced for a walloping by a Category 1 hurricane over the weekend. But by Sunday morning the weather system, called Henri, had been downgraded to a tropical storm.
Joe Scollan, a plumbing contractor, stood outside his home in Montauk in steady, not sopping, rain, buffeted by wind that was far less than the gale that had been expected.
“We dodged a bullet,” said Mr. Scollan, 59.
The days leading up to the storm had been a frenzy of preparation, in a stretch of sandy land where mega mansions sit on dunes at high risk of erosion, and where saltwater has flooded homes and wiped away roads in past storms.
In Southampton, the police department had added overnight staff, and the town had readied an emergency shelter to take in possible storm victims, said Jay Schneiderman, the supervisor of the Town of Southampton.
Earlier in the week, East Hampton Town’s public works crews dumped truckloads of sand at beach access points to prevent flooding at high tide. Peter Van Scoyoc, the East Hampton Town supervisor, closed beaches and bays to swimmers on Sunday.
“We spent a furious 24 hours preparing for the hurricane,” Mr. Schneiderman said, “getting equipment staged, and storm drains cleared, and chain saws sharpened, and generators topped off and working.”
But he did not mind that by Sunday afternoon little had been put to use. “We prepared for a hurricane,” he said. “We are happy it was a lesser storm.”
Nevertheless, the Hamptons seemed largely emptied out of the summer hordes that typically would be packing the restaurants and beaches on this peak vacation weekend. Few were out, and many weekend visitors appeared to have left, packing the highways and Jitney buses on Saturday night.
At the Montauk Marine Basin, Ace Auteri, 68, a commercial fisherman, was dockside, making sure his two boats — the “Polar Bear” and the “Misty Rose” — were secure. He and his first mate, John Schoen, planned to stay beside their fishing vessels until the storm petered away, “riding it out,” Mr. Auteri said. They had been at their posts since 5 a.m. “That’s getting up late for us,” he said.
In East Hampton Village, Joe Kastrati, 43, a co-owner of Fierro’s Pizza, said he was pleasantly surprised to wake up Sunday morning to find he could open for business. There was even an upside, he added: With most shops boarded up, on Sunday his pizza parlor was practically the only game in town.
On Shelter Island, milk had been cleared out from the shelves at the local supermarkets, according to Kathryn Klenawicus, a resident who said her phone had been buzzing all weekend with messages from neighbors checking in on one another.
“Shelter Islanders, they are tough, they kind of have that Puritan Yankee mentality to life’s challenges,” Ms. Klenawicus said Saturday. On Sunday, she emailed a reporter an update on the weather conditions from her home on the island: “This storm is a nothingburger.”
Mr. Schneiderman, the Southampton supervisor, said that the towns’ emphasis on preparedness was not an overreaction. Locals still speak of a 1938 Category 1 hurricane that devastated the area, flattening Montauk Village so badly that the entire downtown was relocated further South on the peninsula, to avoid future nor’easters.
“If anything, this is a good exercise in preparedness,” Mr. Schneiderman said.
In the dark hours as Henri churned in the Atlantic below Eastern Long Island and New England, New York City was deluged by historic rainfall.
In Central Park, 1.94 inches of rain fell between 10 p.m. and 11 p.m. Saturday, the most in a single hour at that location “since record keeping began” in the 19th century, according to the National Weather Service.
The 4.45 inches that fell in Central Park on Saturday was also an overall record for Aug. 21, the service said. Around the city and across northern New Jersey and southern Connecticut, three to six inches of rain fell overnight.
The storm crippled parts of the region’s mass transit system. As of 9 a.m. Sunday, the Metropolitan Transportation Authority had suspended train service on five of seven Metro-North Railroad lines and had partly suspended service on Long Island Rail Road’s Montauk and Ronkonkoma lines.
Portions of the New York City subway on the 1 and 3 lines were suspended because of flooding, though service has since resumed. The three airports serving New York City also experienced the effects of the storm, as more than 20 percent of flights were canceled at La Guardia and Newark airports on Sunday and more than 10 percent were canceled at Kennedy Airport, according to the Port Authority of New York and New Jersey, which operates them.
Social media was inundated with images of roadways turned to rivers with cars pushing through them, washed nearly to their headlights.
The National Weather Service reported overnight flash floods in Crown Heights, Bay Ridge, Battery Park, Harlem and on the Throggs Neck Bridge, as well as around Long Island and New Jersey.
Late Saturday night, a few hundred hardy attendees of the ill-fated Homecoming Concert in Central Park sheltered in a backstage tent hoping for an acoustic performance on a makeshift stage from rock stars who had yet to perform.
After hinting at the possibility around 10 p.m., a poncho-clad Mayor Bill de Blasio returned 20 minutes later and said, “we have to ask everybody to go home because the rain keeps coming.”
The fans who had come to hear songs from their favorite records exited into record rainfall.
State officials in Connecticut said on Sunday that about 250 people had been evacuated from nursing homes near the shoreline as Tropical Storm Henri made landfall in neighboring Rhode Island.
Four nursing homes — in Old Saybrook, Mystic, Guilford and West Haven, all operated by Apple Rehab — were evacuated, Paul Mounds, chief of staff to Gov. Ned Lamont, said at a news conference on Sunday afternoon.
“All of those individuals were temporarily moved to other nursing facilities,” Mr. Mounds said.
The news of the evacuations was announced as officials in Connecticut expressed relief that the impact from Henri could have been far worse.
As the storm moved eastward earlier on Sunday, its landfall trajectory shifting toward Rhode Island, it appeared that Connecticut would likely dodge hurricane-force winds, said Nelson Vaz, a meteorologist for the National Weather Service in New York.
But that did not mean that Connecticut would entirely escape disruptions and damage from the storm. Heavy rain and flash flooding could compound the effect of strong winds, particularly in the western and central parts of the state, and could contribute to downed trees and power outages, forecasters and officials said.
Wind gusts in southeastern Connecticut could reach between 60 miles per hour and 70 m.p.h., while in the southwestern part of the state they would likely be between 30 m.p.h. and 40 m.p.h. Those winds will diminish through Sunday evening, Mr. Vaz said.
“The winds will still pose problems in terms of tree damage and line damage but likely not as bad as we feared,” he said.
The storm’s center was expected to cut northwest across Connecticut and Western Massachusetts on Sunday afternoon before turning to the northeast across southern Vermont, New Hampshire and Maine before heading out to sea again.
Rising water in the Housatonic and Connecticut Rivers may contribute to flooding, Mr. Vaz said. The storm surge from Long Island Sound will likely top out at between two and four feet, he said.
Officials in several coastal communities, including East Haven, Madison, Groton and Branford, issued evacuation orders for shoreline residents. Shelters opened for evacuees along the coast on Saturday and Sunday.
In Branford, town officials ordered the evacuation by 7 a.m. Sunday of a few thousand households near the shoreline, along the Branford River and in low-lying areas. The evacuation order was issued on Saturday, when the storm scenarios “were much more dire,” said Thomas Mahoney, the fire chief and emergency management director for Branford.
Residents were told that they would be endangering their lives if they failed to leave their homes before Henri made landfall, and that emergency crews would not be able to get to them at the height of the storm.
A shelter was opened in the high school, with pandemic precautions, including temperature checks and masks, Chief Mahoney said. But no one stayed overnight in the shelter on Saturday. “They’re hardy New Englanders, and it’s very hard” to get them to leave, Chief Mahoney said.
Branford’s evacuation order will expire after the storm passes. Chief Mahoney said he hoped that the worst of the storm would be over by 6 p.m. on Sunday, and perhaps people can return home later Sunday night.
Religious services were canceled in dozens of municipalities across the state, along with concerts and other events planned for the waning days of summer, WTNH reported.
As Henri made landfall in Rhode Island on Sunday, reports indicated about 135,000 customers were without power from New Jersey to Maine. Here’s how power companies are dealing with the storm:
The utility PSEG Long Island said more than 1,200 contractors and additional crews have been brought in to help prepare for the storm. But it warned customers that outages could last seven to 10 days — or up to two weeks if the forecast worsens.
Gov. Andrew M. Cuomo said that power companies in other regions of New York State that could be heavily affected by the storm, including National Grid and Con Edison, had also called in private contractors and additional personnel to help restore power. “I have told them clearly,” he said on Saturday, “this is what we pay the power companies to do, to be ready for storms.”
In New Jersey, the state’s largest utility, Public Service Electric & Gas, told customers to prepare for possible debris and fallen power lines but did not project an estimate for potential power losses.
National Grid, the main electricity provider in Rhode Island, reported more than 80,000 customers had lost power in the state as of noon on Sunday, with more than 51,000 in Washington County.
Gov. Charlie Baker of Massachusetts warned that Henri could cause at least 100,000 residents — and possibly up to 300,000 — to lose power.
The utility Eversource, which provides power to about 1.2 million customers in Connecticut, said that at least half of them could be without power for several days after the hurricane. More than 19,000 customers had lost power as of noon on Sunday.
Henri was downgraded to a tropical storm on Sunday, but it was still expected to bring heavy rain, potential flooding and a dangerous storm surge.
Here’s how to prepare for a hurricane or tropical storm:
Before the storm
Ahead of a storm, the Federal Emergency Management Agency recommends signing up for local weather alerts and learning evacuation routes.
In the event of a power loss, the National Weather Service suggests having a battery-operated radio for news updates.
The Red Cross suggests preparing an emergency kit with the following items: water (enough for one gallon per person per day), nonperishable food, a flashlight, a first aid kit, a multipurpose tool, hand sanitizer or sanitation wipes, important personal documents, blankets and maps of the area.
FEMA also recommends preparing a “go bag” with essential items, such as medications, and securing important documents, such as financial, medical, school and legal records.
During the storm
During a storm, FEMA suggests staying away from windows in the event of high winds, and seeking shelter on the lowest level of a home in an interior room, such as a closet.
If there is flooding, FEMA says people should seek higher ground. In the event of flooding, the National Weather Service says those driving should never drive through flooded roadways. Two feet of flowing water is enough to float a vehicle.
Residents should heed guidance from local officials, and promptly follow any evacuation orders.
After the storm
Once a storm has passed, the authorities still urge drivers to avoid flooded roadways. Anyone who evacuated should wait to return until local officials say it is safe to do so.
Residents in an area affected by a storm should also avoid drinking tap water unless local officials say it is safe to use.
Having an ample supply of clean water is a top priority during extreme weather systems such as Tropical Storm Henri.
“You don’t know what is necessarily going to happen due to the storm’s impact,” said Stefanie Arcangelo, an American Red Cross spokeswoman. “The storm could impact the public water system.”
Often during or immediately after a storm, a boil water advisory will be issued, meaning there could be contaminants in the water that could make it unsafe to drink, she said.
That’s why the American Red Cross and the Federal Emergency Management Agency recommend that people store a gallon of water per person per day just in case a storm damages the water system or knocks out electricity, which could prevent people from boiling water.
The average person drinks about half a gallon of water, but people will also need water for food preparation and hygiene, FEMA said.
“To prepare the safest and most reliable emergency supply of water, it is recommended that you purchase commercially bottled water,” FEMA said. “Keep bottled water in its original container, and do not open it until you need to use it.”
If people don’t want to buy water in plastic bottles, they can put regular tap water in clean, tightly sealed containers or bottles, FEMA said.
If water supplies run low, drink the amount needed that day and then try to find more the next day, the agency advises, adding that reducing activity and staying cool can minimize the amount of water the body needs.
Hurricanes and tropical storms are defined by their powerful winds. But the storm surges they produce can often prove just as destructive in coastal communities.
Tropical Storm Henri was expected to create dangerous storm surges in parts of Long Island, Connecticut, Massachusetts and Rhode Island.
Storm surge is defined as an abnormal rise in the ocean level generated by a storm, over and above the predicted astronomical tide. The surges are produced by ocean water moving inland, pushed by the force of the wind.
In the open ocean, hurricanes can pound the water without producing a surge. But near the coast, the shallower water is blown inland, threatening property and lives.
The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and dangerous waves, the National Hurricane Center said.
Surge-related flooding depends on the timing of the surge and the tidal cycle, and can vary greatly over short distances, the center said.
In 2008, Ike, a Category 2 hurricane that made landfall near Galveston Island in Texas, produced surges of 15 to 20 feet above normal tide levels, the center said. Property damage was estimated at $24.9 billion.
The National Hurricane Center said that areas that are placed under a storm surge warning are at risk of “life-threatening inundation.” People in those areas should heed any evacuation instructions from local officials, the center said.