Long Island weather: Extreme cold and high winds, with snow possible Sunday night

The coldest air mass of the winter season so far is coming to Long Island on Friday and Saturday, a prelude to a storm possibly bringing an "accumulating" snowfall starting Sunday night, the National Weather Service said.

The frigid arctic air arrives Thursday night, with wind chills dangerously close to zero. Then, on Friday, highs aren't expected to get out of the low 20s, the weather service said.

The weather service says the big chill is a "piece of the polar vortex over eastern Canada" that is dropping onto the Northeast, along with strong northwest gusts of up to 30 mph to 40 mph that will produce wind chills in the single digits Friday.

Gov. Andrew M. Cuomo urged New Yorkers to prepare, saying in a statement Thursday: "Being outside in these conditions can go from uncomfortable to deadly in a matter of minutes, especially for children and the elderly."

The weather service, in a Thursday afternoon statement, also warned about the Sunday storm, saying there is a 50% to 70% chance the tristate region could experience "accumulating" snow from the two-day system. But as of Thursday evening, the snow was predicted to be heavier for areas north and west of Long Island.

That could change if the storm tracks farther south than predicted, forecasters said. That would result in greater snow accumulation potential for coastal areas, and perhaps lighter accumulation for the interior.

And if the storm veers closer to the coast than predicted, Long Island would see more rain and less snow, but there would still be strong winds and coastal flooding.

Saturday should be sunny with a high near 28 and less wind. Sunshine should be abundant Sunday, and the high during the day will rise to 31 before possible storm conditions take over Sunday night, forecasters said.

On Monday, temperatures will climb during the day to a high of 33 degrees and the 50% chance of precipitation includes both rain and snow.