A “significant Nor`easter storm” will impact our region this weekend, with snow, strong winds and coastal flooding, according to National Weather Service meteorologists — but they remain unsure about how much snow it will bring to Long Island, especially across the East End, where warm air and ocean temperatures could mean snow will mix with or turn to rain on Saturday.
Computer models are in “good agreement” that a major winter storm will affect the region Friday night into Sunday, according to the latest NWS forecast discussion, posted on the agency’s website at 4:23 a.m. today.
The forecast: A low pressure system currently making its way across the midwest will strengthen as it moves off the southern Atlantic coast and turns northeast. It will make slow progress north, parallel to the U.S. coastline, developing into a “double barrel low” Saturday night into Sunday. It then treks east of the 40/70 benchmark on Sunday.
The uncertainties: Forecasters are looking to resolve the impacts of warmer air and ocean temperatures on precipitation types associated with the storm. Rain is likely to “at least mix in over the twin forks,” the discussion says. But a changeover to all rain is a possibility for Long Island for a period of time.
Precipitation amounts are also uncertain. Forecasters say a 1- to 2-inch “liquid equivalent” is not out of the question. How that translates into snowfall amounts depends on how wet the snow is and how much precipitation falls as rain.
“By nightfall on Saturday, generally there could be 6-8 inches of snow from portions of northeast New Jersey, New York City, Long Island and southeast Connecticut — with Lesser amounts over the twin forks due to snow mixing with rain,” according to the weather service.
“This still a very uncertain forecast,” the weather service said. “The only thing we can be fairly certain of is that it will precipitate and it will be windy.”
The forecast calls for possible wind gusts Saturday afternoon of up to 50 mph.
With Saturday’s full moon, coastal flooding will also be an issue, the weather service said.