The brunt of a nor'easter -- likely packing rain, but not snow for Long Island -- was expected to start just before Tuesday morning's commute, lasting right through the evening drive home time, forecasters said.
While a high wind watch was downgraded to an advisory, street flooding remained a major concern, with 2 to 3 inches of rain forecast by late Tuesday; coastal flooding at high tide and the higher gusts of between 40 mph and 50 mph.
"The worst conditions will be during the daylight hours Tuesday, to about 6 p.m. and a little beyond," said Tim Morrin, National Weather Service meteorologist at Upton. Rainfall is expected to be widespread and moderate, with bands of heavy rain moving through, said meteorologist David Stark.
With temperatures right around freezing, the Monday evening commute could be slippery for those in Suffolk County following earlier "ocean effect" light snow and flurries, the National Weather Service said. The flakes resulted from an "ocean effect," and were not part of the nor'easter forecast for Tuesday, the weather service said.
The storm is expected to "bring minor to moderate coastal flooding and significant beach erosion along the Atlantic Ocean shores," the weather service said.
A coastal flood warning was in effect until 11 a.m. Tuesday for Long Island Sound shores in Nassau and western Suffolk, meaning minor to moderate flooding. A coastal flood advisory was upgraded to a warning for Nassau and southwest Suffolk along the South Shore from 7 a.m. to 1 p.m. Tuesday, but an advisory continued for the north and south forks.
"We're on alert," said Wayne Horsley, Long Island director of state parks. "A nor'easter is something we are always concerned about. The parks are ready."
Loose items such as garbage cans were taken in, equipment was moved to higher ground, with Jones Beach reporting that a bulldozer, backhoe, loader and sandbags were at the ready should need arise, he said.
Of concern is Ocean Parkway between Tobay and Gilgo beaches, he said, which sustained damage during superstorm Sandy. As the site of a former inlet, it represents "a natural weakness" that parks officials watch.
Already, water from Sunday night's high tide had come right up to the parking lot at the east end of Captree State Park, Horsley said, where stone and sand barriers were added Monday in preparation.
A high wind watch for Tuesday was lessened to a wind advisory, though gusts of 40 to 50 mph were still expected, Stark said. Impacts could include downed tree limbs and resulting power outages, as well as damage to holiday decorations.
PSEG Long Island has "performed system checks on critical equipment;" reviewed availability of key materials; and arranged for additional line crews, tree trimmers and support staff to be on hand, a spokeswoman said.
Winds are expected to diminish by Tuesday night, Stark said, with widespread rain morphing into showers and then scattered showers by Wednesday afternoon and evening.