The first major winter storm of the season, which blasted the western and northern Plains with record snowfall, is dragging the first legitimately Arctic air mass of the season across much of the country.
By early next week, the entire contiguous United States should be in the throes of below normal temperatures. This is an unusual occurrence in an era so often dominated by warmer-than-normal temperatures because of human-caused climate change.
And the cold air will be reinforced as next week wears on. An atypically intense high-pressure zone over Alaska and southeast Canada is set to dislodge much of the available cold from the northern latitudes into the Lower 48.
A Bismarck blizzard
It's not uncommon for snow in the northern Plains during November, but the amount that fell with this storm, which is ushering in the nationwide blast of frigid air, was extraordinary.
Seventeen inches accumulated in Bismarck Thursday, the city's second snowiest day on record and just 0.3 inches from the top spot. Weather.com meteorologist Jonathan Erdman tweeted that more than twice as much snow fell from that single storm than Bismarck sees in an average November: 8 inches.
Several reports of around 2 feet of snow came in from central North Dakota, not far from Bismarck. These include 24 inches near Mandan, 22 inches in Steele and 19 inches near Lincoln. Winds gusted as high as 40 to 50 mph to create drifts of 3 to 5 feet in spots.
A long swath of at least 8 to 12 inches stretched from near Yellowstone National Park, through much of eastern Montana, North Dakota and into northern Minnesota. At least several inches fell as far south as central Wyoming and southwest South Dakota.
Roads in and around Bismarck remained largely shut Friday morning, but conditions were slowly improving across the state.
On Friday morning, a powerful cold front extended from near the low pressure that caused the blizzard — near Lake Superior — to the Texas-Mexico border. This cold front will continue to slide eastward Friday, eventually merging with the remnants of Hurricane Nicole and clearing the East Coast by early this weekend.
Given very warm conditions ahead of the front — including some record highs — a large portion of the Plains and Midwest have seen a 24-hour temperature change of up to 50 degrees.
Actual temperatures early Friday ranged from minus-4 in Great Falls, Mont., to 28 in Kansas City, Mo. Single digits and teens dominated the snowy northern Plains, with 20s and 30s stretching from the Texas Panhandle to Milwaukee. Wind chills were running about 10 to 15 degrees below air temperatures, with most of the northern Plains feeling like zero or below.
Temperatures behind the front are expected to run about 10 to 20 degrees below normal, except 20 to 30 or more below normal in Montana and the Dakotas. Friday's highs range from the teens near the Canadian border to the 20s and 30s in much of the Midwest. Saturday morning lows are forecast to drop below zero in much of the northern Plains, with single digits as far south as the Nebraska-Kansas border and 40s to the Gulf Coast.
While the cold front clears the East Coast by early Saturday, it will take some time to get the cold air over the Appalachians. By Monday, the entire Lower 48 — except for a few small pockets — is likely to be dealing with below normal temperatures.
As the first cold shot takes control of the country and then wanes a bit, a sprawling high-pressure zone is set to develop and become unusually strong over western North America next week. This is a recipe for dropping air straight from the North Pole into Canada and much of the contiguous United States.
Prepare to hear that it's warmer in Alaska than any number of places as the cold air is dislodged southward. Also prepare for a midwinter-like slap in the face from icy air.
Mid- to late next week, frigid conditions will plunge into the Plains. Readings 30 to 40 degrees below normal are possible again by Friday in the northern Plains and Rockies. While the air mass will probably moderate somewhat as it shifts eastward, temperatures 10 to 20 degrees below normal will be widespread headed into next weekend in the central and eastern U.S.
It's too far out to provide any real detail, but with cold air and a relatively active storm track, there may be some chances for wintry weather.
The first such opportunity may arrive in the middle of next week, and it could bring a chance of snow for the Midwest and Ohio Valley. The Northeast, probably north of Washington, will also need to watch this potential wintry weather maker as it progresses.
There are some hints that the cold pattern will ease in about 10 days to two weeks, allowing for a thaw around Thanksgiving, but confidence is low in projections that far out.