A warning sign flashes for motorists on the expressway into Boston as snow starts to fall on Friday.

Morning rush hour pedestrians make their way to work on Delancey Street in New York on Friday.

Sanitation workers use tractors to pile up salt at a depot Friday in New York. A storm poised to dump up to 3 feet of snow from New York City to Boston and beyond beginning Friday could be one for the record books, forecasters warned.

A pedestrian walks through the snow in Washington Park on Friday in Albany, N.Y. Parts of the New York region still cleaning up from Superstorm Sandy are bracing for a winter storm that's expected to blanket the Northeast with heavy snow Friday and Saturday.

Jack Percoco of Cambridge, Mass., reaches into depleted shelves for milk at a supermarket in Somerville, Mass., on Friday.

Pedestrians cross a snow-covered street in Toronto on Friday. A blizzard of potentially historic proportions threatened to strike the Northeast has many cancellations at the three big airports in the New York area.

Vehicles wait in line as gas is delivered to a station in Ellington, Conn., on Friday. Many stations in the area are out due to a pending storm.

Andre Tranchemantague, left, and Will Guerette, ski on a snow-covered road as they make there way to a bar during the early stages of a snow storm on Friday in Portland, Maine. A snowstorm sweeping into Maine already has dumped half-a-foot of snow around Portland and contributed to a 19-car pileup.

TV monitors at Logan International Airport in Boston show canceled flights Friday morning. Some 3,700 flights in the Northeast have been canceled.

Mary Ann Bova walks along a slippery snow-covered sidewalk during a winter storm in Buffalo, N.Y., on Friday. In some upstate areas, snow fell early Friday morning and was expected to increase throughout the day, with the heaviest accumulations expected in eastern New York on Friday night.

A group of men help push a sports car up a snow-covered street in the Old Port section of Portland, Maine, during a snow storm Friday.

Two travelers catch the last train into Boston from the Andover, Mass., train station as snow falls Friday. The MBTA will suspend all transit service in the late afternoon due to the storm.

A couple walks through a near-deserted Faneuil Hall Marketplace as snow falls on Friday.

A man walks down the steps of Boston City Hall as snow falls on Friday.

With snow accumulating on Route 93, cars head toward the New Hampshire border prior to a mandatory Massachusetts statewide driving ban in Andover, Mass., on Friday. Mass. Gov. Deval Patrick declared a state of emergency Friday and banned travel on roads as of 4 p.m.