A winter weather advisory has been issued through 7 p.m. for southern Nassau and southwestern Suffolk, telling of "light freezing rain and sleet on top of earlier snowfall," the National Weather Service said.
Roadways are expected to be slippery, and drivers should be aware of hazardous conditions, especially on untreated surfaces, the service said.
A winter weather advisory for northern Nassau and Suffolk has been extended to 7 p.m., the service said.
For most of the Island, snow had turned to rain by late afternoon, but dropping temperatures in the coming hours could overlap with the last of the precipitation, meaning a brief return to freezing rain or snow for the evening commute, said Adrienne Leptich, a weather service meteorologist in Upton.
Precipitation was expected to clear out of the area by 6 to 8 p.m., she said.
The weather service said that the fast-moving storm system, which started dropping snowflakes over Long Island before dawn, was expected to bring 1 to 2 inches of snow along the South Shore and to communities south of the Long Island Expressway, while areas north of the expressway to the North Shore could get 2 to 4 inches.
As of 1 p.m., a snow total of seven-tenths of an inch had been recorded at Long Island MacArthur Airport in Ronkonkoma; eight-tenths of an inch at Kennedy Airport, and nine-tenths of an inch at LaGuardia Airport, the weather service said. Also as of early afternoon, trained spotters or weather service personnel had reported 1.5 inches of snow in East Northport, 1 inch in Upton nine-tenths of an inch in Stony Brook, and as of 4 p.m., 1.3 inches in Orient, the service said.
Several accidents Tuesday morning caused delays on major roadways, including the Long Island Expressway and the state parkways, according to the state Department of Transportation website, informny.com. Between about 7 and 8 a.m., six traffic alerts were posted on the site -- all accidents in Nassau County.
The Long Island Rail Road issued a winter weather advisory, urging riders to "take care when traveling during inclement weather and allow for additional travel time. Customers should use caution when entering and exiting trains, and on platforms and staircases."
With Gary Dymski