The winter’s largest snowstorm is heading toward Maine and threatening to drop as much as 18 inches of heavy, wet snow on most of the state starting Wednesday afternoon and lasting through Thursday.

James Brown, a meteorologist with the National Weather Service in Gray, said nearly all the computer models that forecasters use are in agreement on this nor’easter, which is expected to roar into Maine on Wednesday afternoon.

Brown said the snow should start falling and winds blowing over the Portland area sometime after noon and by around 4 or 5 o’clock “it will be snowing like crazy.” Brown said the storm will intensify during the evening and early morning hours before tapering off around noon Thursday.

By the time the storm ends, Greater Portland will likely have between 12 and 18 inches of snow on the ground, making it the heaviest snowfall in the city since Jan. 4-5 when Portland got 12 inches. Northern areas of the state could get 8 to 12 inches of snow.

There is a slight chance the storm could turn to rain on the coast, but Brown said he wouldn’t bet on it. As confidence in the storm’s track grew, the National Weather Service issued a winter storm watch Monday. The winter storm watch will take effect at 4 p.m. Wednesday and remain in effect through Thursday at 8 p.m.

Snow will stick around until Friday in northern Maine.

Winds could gust from 35-45 mph along the coast. Gusts of up to 50 mph could be felt Down East, WCSH reported.

Because the snow will be wet and heavy with strong wind gusts, Brown said he would not be surprised if there are power outages.

Wednesday’s nor’easter is the second major storm to blast the East Coast in the last week. Coastal regions in Maine and to the south are still recovering from that storm, which knocked out power to millions of homes and businesses and caused severe coastal flooding.

As much as 6 to 9 inches of snow could fall starting late Tuesday in New York’s five boroughs, northern New Jersey, and southern Connecticut, the National Weather Service said. Some areas could get as much as a foot. There are a few wrinkles in the forecast, though, that could mean more rain in some areas.

“Overall, we just felt there was a 50 percent chance of at least six inches of snow that is why we issued the winter storm watch,” said Brian Ciemnecki, a weather service meteorologist in Upton, New York. “It doesn’t mean we’re going to get six inches.”

There is still a chance the storm will track closer to the coast, which could mean more rain for New York and coastal areas, cutting down on snow amounts, Ciemnecki said.

The storm will form out of a winter system that is coming across the Great Plains now, prompting blizzard warnings from North Dakota to Nebraska. The strong winds and dry air in its wake has also raised the chances of wildfires throughout Colorado, Kansas and Oklahoma, the weather service said.

On Friday and Saturday, the East Coast got walloped by a nor’easter that left 2 million homes and businesses without power at its peak, grounded thousands of flights, halted Amtrak trains on the Northeast Corridor and caused massive flooding to coastlines. New York Governor Andrew Cuomo declared an emergency in Westchester, Putnam, Dutchess and Sullivan counties.

Along the Massachusetts coast, Boston recorded its third highest tide on Friday and the region was raked by wind gusts as high as 97 miles per hour. On Sunday, residents were still pumping sea water out of homes and many coastal roads remained closed with higher than normal water lurking just beyond seawalls.

The storm set to form Tuesday and strengthen into Wednesday won’t bring that kind of fury to the coastline. But because the area has already been hurt, it will be more vulnerable. Steady winds of 15 to 20 mph are likely with gusts up to at least 30 mph, said Frank Pereira, a forecaster at the U.S. Weather Prediction Center in College Park, Maryland.

“That is going to have some significant impacts especially across those areas that were impacted by the last one,” Pereira said.