Long Island weather: Flash flood watch, high winds Sunday

Sunday’s forecast for Long Island offers some true winter misery: cold rain until the midafternoon, followed by freezing rain as temperatures fall from 45 degrees at 8 a.m. to 27 later on, according to the National Weather Service.

Still, the Island was expected to be mostly spared the weekend snow initially predicted, which still could blitz upstate New York. And Monday’s holiday for civil rights leader Martin Luther King should at least be sunny and clear — though intensely cold, with a high of just 14 degrees.

While NWS forecasters are predicting little to no snow and no ice for Sunday, daytime wind gusts could hit 37 mph — and 38 mph at night.

A flash flood watch for Long Island that begins at 1 a.m. should expire by Sunday afternoon, the NWS website said.

As much as 2½ inches of rain could fall, forecasters said, and any flooding caused by the rain "will be exacerbated by coastal flooding during the Sunday morning high tide," the weather service said.

Flyers probably will wish to check with local airports before leaving home.

On Saturday, LaGuardia Airport said there had been 57 cancellations as of 5 p.m. Kennedy reported 162 cancellations. 

Temperatures Sunday will zoom from a high of about 45 degrees at 8 a.m. down to the 27 for the rest of the day, before nose-diving to 7 degrees or so before sunrise Monday.

The weather service also said a flash freeze is likely late Sunday into early Monday as the temperatures drop, with "dangerous wind chills between minus 10 and zero."

"When you are talking about minus 5, minus 10, minus 15, that is serious," Gov. Andrew M. Cuomo said Saturday at an afternoon storm briefing upstate, where the precipitation forecast still called for plenty of snow. "That is a health and safety risk."

Sunday’s powerful wind gusts could down tree branches and power lines, meaning some Islanders could lose electricity.

There is also a coastal flood advisory on Sunday from about 6 a.m. to 1 p.m. for areas on the Long Island Sound and the Peconic and Gardiners bays, the NWS said.

Monday’s cold snap should be fleeting, however, the NWS said. Though that night’s low will be 9 degrees, a sunny Tuesday should hit a high of about 27.