Long Island forecast: Up to 1 inch of snow possible

Up to 1 inch of snow is possible on Long Island overnight Friday into Saturday, with another coastal storm expected to quickly follow, according to the National Weather Service.

A high pressure system departed Friday as moisture spun up from the Gulf, starting as rain into Friday night. “The transition to pure snow takes place overnight into early Saturday morning across Northeast New Jersey, the Lower Hudson Valley and Southern Connecticut with the rain starting to mix with snow closer to the coast,” the weather service said.

Friday night will be brisk, with a low around 37 with winds expected to gust up to 28 mph. 

Risks include minor coastal flooding along the western Long Island Sound, Jamaica Bay, the western Great South Bay, and the Peconic and Gardiners bays with the Saturday night high tide, the weather service said. Some isolated moderate coastal flooding is possible along the South Shore bays near Freeport.

Bouncing between rain and snow, the precipitation should taper from west to east by early Saturday afternoon. High pressure will then build in from the northwest, clearing skies.

The latest data suggests the North Shore, initially expected to get an inch or two of snow, now might not get that much, explained weather service meteorologist Brian Ciemnecki.

“The forecast models just came in slightly warmer than the previous run," Ciemnecki said Friday. “As of right now, maybe you get some snowfall, some time late tonight into early Saturday morning, but right now, it looks like everything stays under an inch.”

More rain on the way

Sunday will be cloudy, with a high around 44 degrees. Rain becomes likely that night as various low pressure systems, including “multiple shortwaves,” sail in from the west and possibly join forces.

“The southern stream shortwave produces a coastal low pressure off the Mid-Atlantic coast that may very quickly intensify as the energy from the northern stream shortwave phases with it,” the forecasters said.

Shortwaves are disturbances in the upper atmosphere that can spur thunderstorms, for instance.

Though this storm’s track typically means New Yorkers can expect snow, too little cold air “especially for the coast,” means it will mainly produce rain, the weather service said.

Any showers will likely continue Monday and possibly into Tuesday.

Daytime temperatures will stick to the 40s. At night, they will drop to around freezing.

Skies should be at least partly clear by Wednesday and mostly sunny Thursday.