A powerful nor’easter roared into Maine on Thursday, turning into a blizzard packing heavy, drifting snow and gusting winds that created whiteout conditions and caused traffic accidents, power outages and flooding along the coast.

Eric Sinsabaugh, a meteorologist with the National Weather Service in Gray, said the area over southern and coastal Maine was officially in a blizzard by late Thursday afternoon, after seeing three consecutive hours of sustained wind gusts of at least 35 mph and visibility that was restricted to a quarter mile or less.

Snow fell at a rate of between 1 and 2 inches per hour Thursday afternoon, and was expected to accumulate to a foot or more in Portland.

Final snow totals probably won’t be available until Friday, Sinsabaugh said, but as of Thursday night there were accumulations of 11 inches in Gray, 11.9 inches in Yarmouth, 11 inches in Freeport, 7 inches in Brunswick and 12 inches in Portland.

Portland and coastal areas were expected to see a total accumulation of 12 to 13 inches, and inland areas between 7 and 13 inches. Down East will see the highest accumulations, with up to 16 inches expected along the coast.

Mal Walker, a meteorologist with the weather service office in Caribou, said Thursday’s storm was one of the most powerful to hit the East Coast in recent memory.

Its energy was so great that it caused a lightning strike Thursday afternoon about 25 miles southwest of Bangor. The phenomenon is known as thunder snow, Walker said.

“It’s basically a thunderstorm that produces snow instead of rain,” Walker said.

The heavy snow was expected to taper off in Portland before midnight Thursday, but snow on the ground continued to blow and drift. Sinsabaugh said the wind gusts also will begin to die down overnight before picking up again Friday, with gusts reaching 25 to 35 mph.

RECOVERING AS FRIGID AIR MOVES IN

Meanwhile, “Thursday’s storm will usher in some of the coldest air of the season,” Sinsabaugh warned. Wind chills will drop to 10 to 20 degrees below zero by Friday afternoon, and plunge to 20 to 30 below zero Saturday, he predicted.

Schools were closed throughout the region Thursday, and Portland said there would be no classes on Friday as well.

South Portland also canceled classes Friday, and school districts such as Cape Elizabeth and Falmouth announced a two-hour delayed start.

The Maine Legislature canceled all of its public hearings and work sessions scheduled for Friday. Legislative offices will open Friday at 10 a.m.

Portland spokeswoman Jessica Grondin said City Hall and all city buildings won’t open until 10 a.m. Friday.

Thursday’s storm also added a 2-foot surge to the midday high tide, causing damaging floods along parts of the coast. The surge pushed the high tide in Portland to 13.79 feet shortly before noon, the third-highest tide there since record-keeping began in 1912.

All Thursday flights out of the Portland International Jetport were canceled, and seven of 35 departures scheduled for Friday also have been canceled, the airport announced. Jetport officials are advising all passengers to check with airlines before venturing out Friday.

Amtrak canceled most rail service in Maine on Thursday, with the exception of one Downeaster trip to Boston.

The first power outages were reported before 10:30 a.m. Although outages climbed to nearly 4,000 by 6:30 p.m., they had declined to below 1,000 as of 9 p.m.

Emera Maine, which serves customers in northern and Down East Maine, reported 370 outages as of 9 p.m.

WARMING SHELTERS, COASTAL FLOODS

Some communities began opening warming shelters Thursday morning in anticipation of power outages later in the day. The towns of Brunswick and Georgetown opened recreation and community centers as 24-hour warming shelters.

The Freeport public safety building opened as a warming center for residents, as did the Yarmouth Town Hall community room and the Riverton Community Center in Portland, which will remain open until 6 a.m. Friday. An up-to-date statewide list is available at maine.gov/mema/mema_masscare.shtml.

Wind-driven snow piled up along roads throughout the day Thursday, when most motorists seemed to have taken the warnings to heart and stayed indoors and off the roads, according to police dispatchers around southern Maine.

The same held true for boats, the U.S. Coast Guard said.

“There were a lot of vessels offshore yesterday, and there were a lot of vessels this morning heading in,” said a Coast Guard dispatcher at the Sector Northern New England call center. “So it looks like everyone heeded the advice.”

The storm surge arrived around high tide at 11:30 a.m., flooding Portland Pier and Marginal Way in Portland. The town of Scarborough had to close the heavily traveled stretch of Route 1 that traverses the Scarborough Marsh in the afternoon when high tides flooded the road. The weather service issued a coastal flood advisory for 12:01 to 2 a.m. Friday, when the tide would crest again.

WCSH-TV reported that Webhannet Drive in Wells, which runs past Wells and Moody beaches, was completely underwater Thursday afternoon, as was Ocean Avenue in Kennebunkport. The locals said it was the highest they’ve seen the water since the Patriots’ Day storm in 2007.

On the Maine Turnpike, authorities lowered the speed limit to 45 mph, but slide-offs and crashes continued, according to tweets from the Maine Turnpike Authority. No injuries were reported.

In Saco, a tractor-trailer slid into a ditch next to New County Road shortly before 10 a.m. No one was injured, and the tractor-trailer was not blocking the road. Because of the severe weather, it could not be towed.

“Once this thing blows over, they’ll tow it out then,” said Saco Police Deputy Chief Jack Clements.

SNOWPLOW TRUCKS OUT IN FORCE

Gov. Paul LePage issued a statement Thursday morning that all state offices would be closed for the day.

“Avoiding unnecessary travel will keep accidents to a minimum and allow state and municipal road crews to safely go about their work,” LePage said in the statement.

State, municipal and private plow trucks were out in force trying to clear the lightweight, drifting snow.

“There will be, at the height of the storm, 350 (state) plow trucks out,” said Ted Talbot, spokesman for the Maine Department of Transportation. “It’s all-hands-on for this storm.”

Portland Police Chief Michael Sauschuck said the city appeared to be well-prepared for the storm. “I think a lot of people took precautions,” Sauschuck said Thursday morning.

He asked people to check on neighbors, especially seniors who may not be well-connected through the internet and social media.

As the storm intensified around noon in Portland, 40 plow trucks and loaders were focused on keeping major streets and roads clear, said Public Works Director Chris Branch.

“We’ll concentrate on residential side streets later,” Branch said.

South Portland Public Works Director Doug Howard said he had 18 city trucks clearing streets and seven additional trucks contracted to keep streets clear around the Maine Mall. “I brought in an extra piece today to make sure we had enough,” he said. “We’re in full-scale plowing operations.”

BUSINESSES CLOSE, SHELTERS FILL UP

With Mainers hunkered down, southern Maine business were either closed, or quiet. But that wasn’t the case for homeless shelters.

Donna Yellen, chief program officer at Preble Street, said 300 to 400 people had visited the resource center by midafternoon Thursday. And 50 people came to the food pantry earlier in the day.

“Watching people come into our resource center with a layer of snow on their backpacks and their shoulders is hard to see,” she said.

Yellen said she also saw acts of kindness. Clients at the resource center were constantly shoveling the entryway and mopping the floors. Those in line for the showers allowed others who were newly in from the cold to go first. People encouraged their friends who normally camp outside to seek shelter.

“There’s so many people just looking out for each other,” Yellen said. “At the same time, there’s people we are really worried about.”

Over at Portland’s day shelter on Oxford Street, 91 people had checked in by 1:30 p.m. Shelter Director Rob Parritt expected that number to keep growing.

“People are tired and wet, but it’s fairly harmonious,” he said.

Parritt said the shelter had lifted most restrictions for shelter guests Thursday night to ensure that people come in from the storm.

After the storm passes the area Friday, the rush of cold air will begin, with temperatures expected to drop steadily throughout the day. Saturday’s daytime high isn’t expected to get above 5 degrees, said Sinsabaugh, the weather service meteorologist.

Overnight lows Saturday will drop as low as minus 10. Factoring in the wind chill, it will feel like 20 to 30 below that night. Even colder temperatures, 30 to 40 below zero, are expected in the western mountains, he said.

TRANSPORT SERVICES DISRUPTED

The large storm pounded the East Coast from Georgia to New England, wreaking havoc on travel. Thousands of flights in the Northeast scheduled for Thursday and Friday were canceled.

Four people were killed in North and South Carolina after their vehicles ran off snow-covered roads, the Associated Press reported. Another fatality was reported near Philadelphia when a car could not stop at the bottom of a steep, snow-covered hill and slammed into a commuter train, killing a passenger in the vehicle.

In the Portland area, Metro bus service shut down at 11 a.m. Thursday because of predicted blizzard conditions. Service was expected to resume Friday.

Concord Coach Lines canceled all bus service from Maine, New Hampshire, Boston and New York on Thursday.

A Central Maine Power Co. news release Thursday reminded Mainers about precautions to take if they encounter downed power lines.

“Everyone should stay clear of any downed power lines or fallen trees that may be tangled in the lines,” said CMP spokeswoman Gail Rice. “All downed lines should be considered live and dangerous. Customers should leave the cleanup to our crews, who are trained and equipped to handle these situations safely.”

CMP has said it can call in crews from outside Maine if conditions worsen.

Power outages can be reported online at CMP’s website at m.cmpco.com/mt/ecmp.cmpco.com/WebOutage or by calling 1-800-696-1000.

Staff Writers Gillian Graham, Matt Byrne, Kelley Bouchard, Joe Lawlor and Megan Doyle contributed to this report.

Dennis Hoey can be contacted at 791-6365 or at:

dhoey@pressherald.com