Winter Blast Barreling Toward Northeast

Get ready for some wacky winter weather. A powerful nor’easter is going to dump a stinging mix of sleet and rain on the city early Friday that will gradually turn to snow, with up to eight inches expected overnight, the National Weather Service said Wednesday.

It has issued winter storm watch advisories for Friday afternoon and Saturday for the city, Long Island and all of southern Connecticut.

Forecasters are predicting a lot of snow — 10 to 24 inches — across Long Island and into Connecticut.

The city will get walloped with anywhere from six to eight inches of the white stuff, said meteorologist John Murray, mostly Friday night into Saturday.

All eyes are on a cold front moving in from the north that’s set to collide with a rainy system from the south sometime Thursday night.

If the two mix at the right time and the right place, the brewing nor‘easter — named “Nemo“ by meteorologists — could be even larger than predicted.

“It has the potential to be a big one,” said Rob Carolan, a meteorologist and founder of Hometown Forecast Services Inc. in Nashua, N.H., which provides weather forecasting services to businesses and government agencies.

If the worst happens, Boston will be shoveling out from under as much as two feet, while New York City could get hit with about half that, Carolan said.

But the more likely forecast is for snow on a smaller scale — maybe six to eight for the city and 10 or more in upstate New York.

Flakes should start dropping in the city Thursday evening, according to Tim Morrin, a weather service meteorologist in Upton, Long Island.

“Currently we are forecasting some light snow before daybreak, and a change to sleet and rain would be likely on Friday. Then maybe a switch back to snow for Friday night,” said Morrin.

Sanitation Dept. spokesman Keith Mellis said the agency is closely watching the storm predictions.

“As always in the winter season we are prepared for whatever Mother Nature brings,” said Mellis. The agency has 365 salt-spreaders standing by, he said.

“Once we get a weather forecast that looks like the threat of snow, we have them pre-loaded. They’re our first line of defense,” Mellis said.

A blockbuster storm like the city saw in 2010 — when about a foot was dumped across the five boroughs in a post-Christmas blitz — is unlikely, meteorologists said.

Snow has been relatively rare in the Northeast this season. Since Oct. 1, 7.4 inches have fallen in New York’s Central Park, 6.4 inches fewer than normal.

In Boston, 9.6 inches have fallen since Dec. 1, 14.3 inches below normal, according to the weather service.