Flakes could fly as far south as West Virginia if the conditions line up just right. In northern New England, snow may accumulate a few inches deep atop mountain summits.
Most folks won’t see snow, but they will experience a noticeably cooler air mass regardless — about 4 to 7 degrees cooler than average.
The strong cold front that will bring about the shift wasn’t even located in the United States on Wednesday; in fact, it stretched across central British Columbia, Alberta and Saskatchewan in western Canada. Temperatures in Calgary were forecast to peak at 42 degrees on Wednesday, and may not escape the upper 20s this weekend.
The cold front will swing southeast, crossing Chicago and the Midwest on Thursday and the Northeast on Friday. The Eastern Seaboard will actually enjoy an anomalously warm day Thursday with southerly winds ahead of the cold front. The nation’s capital could peak at 77 degrees, while Boston and New York will both enjoy lower to mid-70s.
A soaking rain will accompany the front, arriving along the Northeast Corridor late Friday into Saturday. Rain totals of 1 to 1.5 inches appear likely in New York, Hartford, Providence and Boston, with amounts topping 2 inches in Maine. Behind the front, the cool air settles in. Boston won’t make it out of the mid-50s on Saturday. New York City won’t escape the 50s either.
To the north, however, Saturday’s temperatures will be cooler — as low pressure developing east of Maine draws down. Upper 30s are possible across Vermont and New Hampshire, with lower 40s elsewhere in the Granite State and adjacent western Maine. There’s a chance that, above about 3,000 feet, the flakes could fly where temperatures remain low enough for moisture to fall as snow.
“It looks like the northern Adirondacks could see 2 to 5 inches at the higher peaks with 1-2 inches across the higher peaks of the Green Mountains,” wrote the National Weather Service in Burlington. They anticipated snow levels to be primarily above 3,500 feet.
Some computer models on Wednesday afternoon, however, were backing off snowfall forecasts. If this trend continues, amounts may be less than described by the Weather Service and shown in the graphic above and the best chance of flakes might shift toward the high elevations in western and northern Maine.
To the south, cool air pouring into the Mid-Atlantic behind Friday’s front could supply enough chill for a few flakes at the highest elevations of the Appalachians late Friday night into early Saturday morning, but moisture will be scarce. The greatest chances would be above 4,000 feet.
According to Robert Leffler, a retired Weather Service climatologist, who monitors snowfall in the Canaan Valley of northeast West Virginia, the average first snowflakes at 3,715 feet elevation is Oct. 13.
The cooler pattern across the eastern U.S. looks to relent toward next week but there is some uncertainty as to how much. The American model indicates that a series of reinforcing cold fronts will keep any warm-ups brief. But the European model calls for a ridge of warmth to build over the region.
There may be reason to lend credence to the latter solution. The American GFS model has had a bias as of late that simulates cold fronts making too much progress eastward. As such, there is a chance the second half of October leans toward the warmer side.