Credit: News 12 Long Island

Long Islanders will be facing round four Wednesday, as yet another nor’easter is set to impact the area.

Much of the Island could see 12 to 15 inches of snow, with the Twin Forks looking at a possible 6 to 10, thanks to the kind of heavy banding that came with last week’s nor’easter, said Tim Morrin, a National Weather Service meteorologist in Upton.

Snowfall rates of 1 to 3 inches an hour are possible for the afternoon and evening, with visibility at times of one quarter of a mile or less, the weather service said in its Tuesday afternoon forecast.

A winter storm warning is in effect from 6 a.m. Wednesday to early Thursday morning for all of Long Island, forecasters said — and that’s as spring officially kicked off Tuesday.

With precipitation expected to spread over the area around daybreak Wednesday, Long Island could see several hours in the morning of snow/sleet mix, but “the bulk of the precipitation is expected to fall as snow,” the weather service said Tuesday afternoon.

By late morning, “snow could become heavy at times . . . with heavy snow continuing through the afternoon and into the evening across the majority of the region,” the weather service said.

The service also warned that travel will be “very difficult to impossible,” especially during the evening commute, with “significant reductions in visibility at times.”

Suffolk County Executive Steve Bellone said Tuesday afternoon he is concerned that residents who manage to get to work in the morning could find getting home a challenge.

“People are going to wake up in the morning and think it’s OK to jump in their car and go about their business,” Bellone said at a news conference at the county’s public works facility in Commack. “If the predictions turn out to be true, that commute home will be awful, terrible and difficult in some cases.”

He encouraged residents to monitor forecasts all day.

The Long Island Rail Road said it was positioning snow-fighting equipment and antifreeze trains to prevent ice buildup, but riders should anticipate delays and avoid travel, if possible. The railroad may have to suspend service temporarily for snow-clearing activity if accumulations reach 10 or more inches.

The Port Authority said hundreds of flights scheduled for Wednesday at LaGuardia and Kennedy airports have been canceled, while Long Island MacArthur Airport said airlines canceled multiple flights Tuesday evening and through the day Wednesday. Amtrak said it will operate on a modified service on Wednesday.

Dozens of Long Island school districts announced closures for Wednesday, and New York City schools will also be closed.

During the storm, winds on Long Island could gust from 35 to 45 mph. Falling branches, weighed down by heavy snow, could trigger power outages.

Residents also should look for minor to moderate coastal flooding around high-tide times Wednesday, as well as dune erosion in some spots, along vulnerable areas of the North Shore and for South Shore and eastern bays.

The system was shaping up to be “a classic tristate major snowstorm, even in late March,” said Richard Von Ohlen, a News 12 meteorologist. “Pretty amazing on the heels of three previous storms.”

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Yet to be determined, the weather service said, were the timing and location of heaviest snowfall and the degree that snow might mix with sleet.

The next major forecast update is expected around 4 a.m. Wednesday.

With Joan Gralla