Update (March 12, 4 p.m.): The North Fork is still looking at getting the heaviest snowfall on Long Island, forecasters said in an update Monday afternoon.
From the National Weather Service in Upton, meteorologists said 6 to 12 inches will fall on the North Fork, starting around midnight.
A winter storm warning is in effect from midnight until 6 p.m. on Tuesday.
It may begin as a mixture of rain and snow, then become heavier between 1 and 3 a.m. and continue through the morning commute.
The snow will fall steadily through lunchtime, and taper off between 1 and 3 p.m.
There may be some snow showers in the evening, causing roads to become slippery with patchy black ice Tuesday night.
Winds Tuesday will become noticeably stronger after 4 a.m. and last through much of the morning. Gusts of up to 40 mph are expected on the North Fork. They will subside in the afternoon.
Originally (March 12, 8:50 a.m.): Suffolk County is under a winter storm warning with 8 to 10 inches in the forecast for the East End.
The winter storm warning is in effect from 8 p.m. Monday to 6 p.m. on Tuesday for southeast New York and portions of southern Connecticut.
Tim Morrin, a meteorologist with the National Weather Service in Upton, said the most accumulations will occur further east on Long Island.
“This is a true coastal storm staying off shore so that the precipitation would be the heaviest closer to the storm track and that would be the East End,” Mr. Morrin said Monday morning. The South Fork will get slightly more than the North Fork due to its proximity to the storm with Montauk would get slightly more than Orient, he said.
“Any deviation of the track will change those numbers,” he said. “A track further east would bring the precipitation east with it . . . a track further to the west, closer to the coast, will increase the numbers on the East End.”
There is a 1 out of 10 chance that the East End could see up to 15 inches of snow — but that’s the worst case scenario, he said.
The National Weather Service said travel conditions will be difficult, especially during the morning commute on Tuesday and there will be limited visibility. Heavy winds may cause tree branches to fall.
The week started off sunny with highs near 44 expected.
Monday night will bring rain and snow before 10 p.m., turning to all snow afterwards. The low will be around 32. It will be breezy with a north wind 15 to 21 mph, with gusts as high as 31 mph. About 3 to 5 inches of snow accumulation is possible, the NWS said.
Snow will fall on Tuesday, mainly before 2 p.m., with another 3 to 5 inches possible. Temperatures will reach a high near 38. Winds will be out of the northwest at 20 to 25 mph, with gusts as high as 39 mph.
Photo caption: A map from the National Weather Service shows that Suffolk County and portions of southern Connecticut are under a winter storm warning, starting Monday night. (Credit: NWS)