Unusually warm temperatures will be in place ahead of a cold front today from the Southeast into the northern Mid-Atlantic region as a strengthening storm system approaches from the Mississippi Valley. Strong storms are forecast ahead of the cold front as moisture from the Gulf of Mexico works into the Southeast and Mid-Atlantic this afternoon. Much colder air will fill in behind the cold front for tonight and Saturday along with gusty winds.
Farther north, a winter storm will impact northern New England. The heaviest snow, 6+ inches, is expected to remain over the Adirondacks into the Green and White Mountains of New England, spreading into northern Maine. Across the Pacific Northwest, an approaching upper level trough will send a strong cold front into the Northwest tonight, followed by a prolonged period of upslope flow into the coastal ranges and Cascades extending through the weekend.
A strong trough heads through the Great Lakes region before a coastal low develops over the Gulf of Maine. Heaviest snowfall, 6 or more inches, will be across interior Maine, interior New York, and northern New York, with lighter amounts over southern New york, southern New England, and coastal Maine. Lake enhanced snow is expected downwind of Lakes Erie and Ontario, into northwestern Pennsylvania, southwestern New York, and near the Tug Hill Plateau. An area of snow over northern Illinois to southern Michigan continues as a low crosses southern lower Michigan into Ontario Friday afternoon.
A strong cold front will move into the Pacific Northwest tonight, followed by a prolonged period of upslope flow into the coastal ranges and Cascades. Heavy snowfall is expected in the Washington/Oregon Cascades, with slightly lower amounts in the ranges of northern Idaho to northwest Montana. A foot of snow is likely in the northern Washington Cascades.
There is a slight risk of severe thunderstorms across the mid-Atlantic to the Southeast today through early evening.