Thanksgiving snowstorm to blanket Rockies, including Denver

A developing winter storm is about to hit the Rockies and the western Plains on Thanksgiving and Black Friday. Travel hazards are probable as some areas see up to a foot and a half of snow.

Winter storm watches already cover much of Wyoming, the Nebraska Panhandle and Sandhills and a sliver of north central Colorado. That’s where snow totals could top eight inches. Denver could see 3 to 7 inches of snow, falling mostly Thanksgiving night into Black Friday.

Snow could sink as far south as the Four Corners region before the storm system could bring formidable wintry weather to parts of the Plains and Midwest into the weekend.

Major airport hubs — including Denver and Kansas City — could be impacted by the storm. So could stretches of the Interstates 70, 80, 15 and 25.

Flakes were already flying on Wednesday in parts of British Columbia and Alberta; that snow will increase markedly in both coverage and intensity early Thursday across southern Idaho, western Montana and Wyoming. It will surge south into western Utah by the evening and reach the Four Corners region Thursday night.

In some instances, the snow will manifest as a pinwheeling of snow showers and squalls. Visibility in snow will be highly variable, dropping quickly with little to no warning.

Western and central Colorado will see its snow Thursday night through midday Saturday, with the heaviest coming Friday. That’s when most of the snow will fall in Denver, though intermittent snow showers will continue off and on for another day. The storm will drag considerably colder air southward in its wake. Denver will drop from highs near 60 on Wednesday to the mid-20s for Black Friday.

Farther east, into the western Plains, the bulk of the snow will fall Friday in western Nebraska and Saturday in western Kansas.

Two jackpot zones will exist when it comes to snow totals: one in Wyoming, and one in southwest Colorado. Totals of 12 to 16 inches will be most common across Wyoming, with Colorado’s snow be more localized and elevation dependent. The San Juan and Rio Grande National Forests could be buried beneath a foot or more.

In Colorado, there’s a 70 percent chance locations in the mountains west of Interstate 25 pick up 8 inches or more; that’s especially true around Highways 36, 34 and 14.

Denver will probably see a plowable snow, but not crippling amounts.

“It still looks as though we’ll remain within Advisory level snowfall, with accumulations generally 3-7′′ along the urban corridor and locally higher pockets possible west of I-25,” wrote the National Weather Service office in Boulder regarding Denver’s forecast. Boulder could see a bit more snow — perhaps 5 to 8 inches.

Despite cold temperatures sufficient for snow, it’s probable Denver’s snow totals will be a bit less than its neighbors to the west’s. The reason? A “Denver cyclone,” or localized low pressure system, is expected to form and induce northerly winds in the city. That will result in an influx of drier air, slashing snowfall rates.

Elsewhere across much of the Intermountain West, a general 4 to 8 inches is expected in areas on the above map shaded in dark blue or purple, with 2 to 5 inches in the lighter blue.

Snow may spread from Plains into parts of Midwest

Early indications suggest an increasing potential that the storm system will deposit a strip of snow from western Kansas to near Chicago over the weekend. While the storm system won’t be particularly strong, its position is key. It will skim along the southern periphery of Canadian high pressure to the north feeding cold air southward. Moisture, this time from the Gulf of Mexico, will be tugged northwest in between the two systems, like a piece of paper caught between interlocking gears. Where the cold air and snow overlap, accumulating snow is possible.

Kansas City, Mo. may end up close to the rain-snow line Saturday night; it’s still unclear whether it will end up white or just wet. Farther west, double digit snowfall totals are possible in rural Kansas northwest of the rain-snow line.