(CNN) - New England's third nor'easter in less than two weeks slammed parts of the region Tuesday as part of what's expected to be an all-day barrage that could drop as much as 2 feet of snow and bring dangerous whiteout conditions on the roads.
The National Weather Service of Boston officially declared the storm a blizzard at noon Tuesday after three straight hours of blizzard conditions. Wind gusts reached 69 mph in places as much of coastal Massachusetts, Rhode Island, Connecticut, New Hampshire and Maine bore the brunt of the storm.
There were about 175,000 power outages across Massachusetts as of midday Tuesday, Gov. Charlie Baker said. That total is expected to increase as snow falls this afternoon at a pace of about 1-3 inches per hour, he said.
Blizzard warnings had been issued for much of the region, foretelling "dangerous to impossible" travel conditions with strong winds and heavy snow dimming visibility into Tuesday evening or early Wednesday, the National Weather Service said.
Winter storm warnings are in effect through the evening as well for parts of Connecticut, Vermont and New York's Long Island.
Virginia Riley of Boston posted this video on Instagram of the whipping winds and snow.
"It hasn't stopped snowing or blowing and I'd guess we have around 10 inches so far. I love this weather and it hasn't affected me at all," Riley wrote. "But I know it is wreaking havoc with so many others. A storm like this on the tail end of the other two we have had isn't great for some people. I just hope everyone is safe and in a warm place."
Martha's Vineyard Shipyard shared a video of the powerful winds just before noon on Tuesday. While the wind isn't as bad as when last week's nor'easter broke four boats free, "the snow and flooding have really made things interesting," Martha's Vineyard Shipyard wrote on Instagram.
The storm could bring minor to moderate flooding to New England coasts, especially at high tide after 9 a.m. ET. More than 45 million people are under some kind of a weather warning or advisory in the Northeast.
Which places are affected?
Boston is expecting snowfall totals of 12 to 20 inches. In some areas, snow could reach 2 feet. Boston schools are closed Tuesday, and a snow emergency in the city went into effect Monday night.
"It feels like we haven't seen this type of storm since 2015," Mayor Marty Walsh said Monday. "It seems like this one is going to be a big one."
"This storm could bring significant snowfall across much of the Commonwealth, high winds along the coast, southeast and eastern portions of the state, and minor coastal flooding on east ocean-exposed shorelines," the agency said.
Because of the wind, snow and whiteout conditions, officials advised people to stay indoors. The Massachusetts State Police posted a handful of photos of tractor-trailers that jackknifed on snowy roadways, blocking traffic.
The National Weather Service's Boston office is forecasting 8 to 18 inches of snow for parts of Connecticut through western Massachusetts and up to 18 inches for Rhode Island.
One to 2 feet of snow is forecast for parts of New Hampshire and Maine into Wednesday morning.
Public schools in Hartford, Connecticut; Providence, Rhode Island; and Portland, Maine, closed Tuesday.
New York City, under a winter weather advisory, will be spared the heaviest snow, but accumulations of 2 to 4 inches are expected.
The National Weather Service said Monday that Suffolk County in New York, and southern Connecticut would receive a heavy, wet snowfall of 5 to 10 inches, with 1 to 2 inches of snow per hour.
Little or no snow accumulation is forecast for Philadelphia and Washington.
How is travel affected?
About 1,550 flights were canceled Tuesday, most of them scheduled to come to or from Boston Logan International Airport, according to FlightAware.
Amtrak temporarily suspended its Northeast Corridor service between Boston and New York until at least 11 a.m. Tuesday.
In Massachusetts, all ferry services have been suspended in expectation of blizzard conditions. The Boston mayor asked residents to stay off the roads and, if needed, to take public transportation.
What happened in earlier nor'easters?
On March 2, a nor'easter that morphed into a "bomb cyclone" slammed much of the Northeast with heavy snow and rain, hurricane-force wind gusts, and significant coastal flooding. The storm left six people dead from falling trees, and about 900,000 people lost power.
As residents were still digging out from that snow, a second storm hit the Northeast late last week. The storm dropped heavy, wet snow in areas west of Interstate 95 and left one person dead in New York state.