BOSTON — A coastal storm moving off the Mid-Atlantic is spreading rain across southern New England on Thursday, with wet snow expected in the higher elevations of Vermont, western Massachusetts and northern New England before the system pulls away Friday, according to the National Weather Service.

Forecasters at the weather service's office in Norton, Mass., said the next 36 to 42 hours would be wet across southern New England but called the storm "a non-event for most of the region." Rain will spread over the interior Thursday and reach the rest of the region by evening as the storm passes south of Long Island, then taper off from north to south by late Friday. Highs Friday are expected only in the upper 30s in the hills and the mid to upper 40s along the south coast.

Mountain snow

The weather service has posted winter weather advisories through 10 a.m. Friday for parts of Vermont. Eastern Addison and Eastern Rutland counties could see 2 to 5 inches of wet snow, mainly above 1,200 feet, the Burlington office said, with slippery roads affecting Thursday evening's and Friday morning's commutes. In Bennington and western Windham counties, up to 3 inches is expected above 1,500 feet, with 3 to 5 inches possible on the highest peaks, according to the Albany, N.Y., office.

In Massachusetts, colder air pulled in behind the storm could turn rain to wet snow in the Berkshires, where a few inches are possible, and to a lesser extent in the Worcester Hills, where forecasters expect about a coating, mostly on grassy surfaces. A period of light snow in the Connecticut or Rhode Island hills late Friday can't be ruled out, but forecasters called it unlikely.

In New Hampshire and Maine, the weather service office in Gray, Maine, said rain would reach southern New Hampshire Thursday morning and the southern Maine coast in the afternoon. Southern New Hampshire and far southern Maine could see a half inch to an inch of precipitation, mostly rain. Outside the mountains, forecasters expect a dusting to a half inch of snow overnight as temperatures fall near or below freezing. Elevations above 1,000 feet stand the best chance of several inches, and Friday morning commuters should watch for slick spots, the office said.

Wind and coastal flooding

The storm is not expected to bring damaging wind or significant flooding on land. Northeast winds could gust 20 to 30 mph at times, with stronger gusts on Cape Cod and the islands, according to the Norton office. Gray forecasters said winds along the Maine and New Hampshire coast would reach only 20 to 25 mph and that tides there would stay below flood levels.

Up to half a foot of water is possible in low-lying areas near the shore on Cape Cod and Nantucket during Friday afternoon's high tide, the weather service said. Roads should stay passable, though shallow flooding is possible near Nantucket Harbor, including Easy Street. In southern Fairfield County, Conn., minor flooding of up to half a foot was expected near the waterfront through 2 p.m. Thursday, with more minor flooding possible at Friday's daytime high tide, according to the Upton, N.Y., office.

Offshore, gale warnings are in effect for the waters off Massachusetts and Rhode Island from Thursday evening through 7 p.m. Friday, and a small craft advisory covers Boston Harbor and Narragansett Bay. A gale watch is posted for the Gulf of Maine, where seas could build to 5 to 7 feet.

Drier, cooler weather returns for the weekend as high pressure builds in, though blustery winds will linger through Sunday, forecasters said. Highs are expected in the upper 40s Saturday, climbing to the mid-50s by Tuesday and Wednesday, with overnight lows possibly in the 20s.

The Signal reported Wednesday that the storm could bring the season's first snowflakes to parts of the region.