Long Island snowstorm latest: Dangerous storm to bring 10 to 14 inches over Sunday, Monday, with whiteout conditions, sleet Sunday night, NWS says

A sprawling cross-country winter storm is taking aim at Long Island on Sunday, with a massive snowfall expected before a surge of warm air in the evening could turn it to a wintry mix.

But even with that break in the snowfall — which will return Monday when temperatures chill again — Long Islanders can still expect to shovel between 10 and 14 inches of snow, National Weather Service Meteorologist Bryan Ramsey said late Friday. Most of the accumulation will occur Sunday, he added.

Compared with the rest of the tristate, the Long Island forecast remains the most uncertain, depending on the timing and intensity of the system's low pressure and how closely it tracks to Long Island, Ramsey said. The storm's path will determine when and for how long the snow turns to freezing rain and ice.

"A changeover to a wintry mix is possible Sunday evening and could lead to additional sleet accumulation and a glaze of ice before a change back over to light snow later Sunday night," according to a weather service briefing.

A light accumulation of ice, up to 0.2 of an inch, could develop along the South Shore, only adding to the cleanup challenge.

"It’s not going to make it any less difficult to handle," NewsdayTV meteorologist Bill Korbel said. "Every flake will stick and there may be at least 8 inches by Sunday afternoon."

Snow accumulations in the overall tristate area could range from 12 to 16 inches, with northern parts away from the coast getting the higher amounts, the weather service said.

On Long Island, a winter storm warning has been issued by the weather service from 3 a.m. Sunday to 6 p.m. Monday.

Before the storm's arrival, an arctic shot of cold air was to move in. A cold weather advisory was in effect from Friday at 10 p.m. to Saturday at 10 a.m. as temperatures plummet to the single digits Friday night due to high wind chills. While moderating slightly, temperatures will remain subfreezing into next week.

Whether the storm becomes a full-out blizzard depends on the winds and the blowing snow. Forecasters said the system could bring "white-out" conditions with blustery wind gusts of up to 35 mph Sunday night. A blizzard is defined by the weather service as a serious storm with sustained winds "or frequent gusts" of 35 mph and low visibility conditions that lasts for more than 3 hours.

"It’s going to be windy with really heavy snow and visibility could drop to a quarter-mile with blowing snow," Ramsey said.

The giant storm has impacted large swaths of the country, bringing snow, sleet, rain and frigid conditions. The system was leaving the Rocky Mountains and striking the southern plains around 7:30 p.m. Friday, Ramsey said. The storm will then move across the Appalachian Mountains toward the mid-Atlantic states and New England.

Long Islanders should continue to monitor the National Weather Service for updates.

Newsday's Matthew Chayes, Nicholas Grasso and Maureen Mullarkey contributed to this story.

By John Asbury

john.asbury@newsday.comJohnAsbury

John Asbury is a breaking news and general assignment reporter. He has been with Newsday since 2014 and previously worked at The Press-Enterprise in Riverside, California.