The National Weather Service extended its winter weather advisory by two hours on Sunday night, warning of snow, sleet and freezing rain that will snarl traffic and blanket the region with up to an inch of snow.
The advisory, which now covers an additional two hours, through 5 a.m. Monday, also warned of light freezing drizzle in some areas that will transition into snow and sleet, then freezing rain after midnight.
The agency warned of hazardous travel in some areas, especially over overpasses and bridges that are prone to freezing before other road surfaces.
The conditions even led to the closure of the Long Beach Bridge in both directions for a time on Sunday night before it was reopened, according to the Nassau County police..
Temperatures will be in the low 30s, with visibility during moderate to heavy snowfall reduced to less than half a mile at some points.
David Stark, meteorologist with the National Weather Service, warned that driving could be hazardous in the evening hours when there will be sleet and possibly icy conditions.
The snow and sleet will change to rain by early Monday morning as temperatures rise, the agency said.
The advisory, which originally extended to 3 a.m. Monday, covers Long Island and New York City.
The wintry conditions had led to delays at area airports.
Long Island and the New York City region appear to be escaping the brunt of the storm, said Lauren Nash, meteorologist with the National Weather Service.
"Some of the heavier snow bands passed to our south," including Philadelphia and parts of New Jersey, Nash said.
Delays at Philadelphia's airport, for example, were more than four and a half hours on Sunday evening.
Eventually, temperatures were forecast to rise through Monday night, reaching into the high 40s Monday, with showers on and off and overcast skies, according to Stark.
On Tuesday, there was the possibility of a second round of light snow with temperatures in the mid- to upper 30s.
"There is another chance of light snow during the day on Tuesday, about a 40 percent chance. We are monitoring it," Stark said.
Skies will clear Tuesday night, however, and by Wednesday, the high will be about 34 degrees, he said. A taste of the deep cold that has affected the central and western part of the country will start to move into the Long Island region, Stark said.
That frigid air has been oscillating back and forth, pushing in from the Midwest but just hovering near the Northeast. But it will shift significantly toward the east Thursday, bringing below normal temperatures, Stark said.
Then, Thursday and Friday will be clear but very cold, with highs Thursday in the upper 20s.
The normal high for this time of year is about 45 and the low is 32.