A low-pressure system approaching from the southwest brings a stretch of rain to Long Island, starting late Friday, the National Weather Service said.
Meteorologist Tim Morrin of the service's Upton office said about 1.4 inches of rain is expected to fall from late Friday afternoon to daybreak Sunday morning.
"We'll start any time after dark Friday with a light, chilly rain," Morrin said, "and then it's pretty much rain, off and on, all day Saturday."
Morrin said the heaviest rainfall will likely be from about 6 p.m. Saturday into early Sunday morning.
"By daybreak Sunday the rain should be tapering off," he said.
Chance of precipitation ranges from 70 to 90 percent Friday night to Saturday night, and then to about 30 percent Sunday morning, the service said.
Although portions north and west of Long Island are expected to get a wintry mix and some light accumulation of snow, Nassau and Suffolk will escape the white stuff, Morrin said.
Daytime temperatures range from 55 on Friday, to the low 50s Saturday and into the mid 40s Sunday, the service said.
Nighttime temperatures Friday and Saturday are in the high 30s to low 40s, but drop into the high 20s Sunday, the service said.
By that time, skies clear, with daytime temperatures Sunday expected in the 40s and a breezy north wind from 21 to 24 mph with gusts to 36 mph.