A weekend storm that originated as a bomb cyclone in the West earlier this week is destined to bring the most substantial snowfall of the season so far to parts of the mid-Atlantic and central Appalachians in a winter where big snowfall amounts have been absent to this point.
Winter weather advisories have been issued for the northern and western suburbs of New York City into southeastern New England ahead of the weekend storm, and winter storm warnings are in effect starting at across portions of upstate New York and central New England.
The bomb cyclone that hammered Newfoundland, Canada, with blizzard conditions on Friday bringing more than 29 inches (75 cm) of snow to St John's, is responsible for sending fresh Arctic air into the northeastern United States that will pave the way for wintry precipitation this weekend.
Snow started spreading across the Northeast early on Saturday, reaching New England in the early afternoon.
Forecasters say a major snowfall is not anticipated along the Interstate 95 corridor of the mid-Atlantic and only a moderate snowfall is forecast for the central Appalachians to southern New England.
However, enough snow followed by a transition to an icy mix and rain will fall to generate slippery travel conditions and airline delays.
As is often the case during winter storms, the accumulation of snow and sleet will vary from southeast to northwest across the major cities and their suburbs of the I-95 corridor from Washington, D.C., to Philadelphia, New York City and Boston. Enough snow to shovel and plow is likely from western Maryland to southeastern Pennsylvania, central New Jersey, locations close to New York City and in southern New England.
By 9 a.m. EST Saturday, 446 flights had already been cancelled across the region. Travelers can expect more flights to be cancelled into Monday, as crews and aircraft are displaced. Airline delays are highly likely due to deicing operations.
Road conditions will likely deteriorate quickly as snow moves in. The thump of snow on the front end of the storm may bring the bulk of the snow accumulation for locations in southern New England.
For those who must travel, meteorologists suggest allowing plenty of extra time to reach destinations.
Rising temperatures and lighter precipitation, in the form of rain and drizzle in some cases, should allow chemicals to work on the roads and create wet to slushy conditions later in the evening.
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Farther north, most of the precipitation that falls during the storm will occur as snow. This includes the northern tier of Pennsylvania, western, central and northern New York state and central and northwestern New England.
This storm system won't be the only source of wintry precipitation in the Northeast in the coming days.
"Chilly air and gusty winds across the Great Lakes will allow snow to generate off the lakes from west to east," said AccuWeather Meteorologist Courtney Travis.
Factoring in snow from the storm, as well as lake-effect snow that gets underway for the latter half of the weekend, a general accumulation of 6-12 inches is forecast for down-wind locations, with an AccuWeather Local StormMax™ of 16 inches.
Gusty northwesterly winds on the backside of the storm will drag progressively colder air southeastward from Canada later this weekend through the middle of next week.
The pattern will bring episodes of lake-effect snow, flurries and snow squalls.
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