Image
Winter Storm Astro dumped the season's first snow in Bismarck, North Dakota Sunday, with 3.2 inches measured at the National Weather Service office. This first snow in North Dakota's capital city arrived about two weeks later than average. Up to 7 inches had accumulated in North Dakota, as of late Monday morning.

Webster, South Dakota, chalked up the state's heaviest total (8 inches) and patchy freezing drizzle had deposited a thin layer of ice on roads in parts of northern South Dakota. Parts of western and central Minnesota had measured up to 13 inches of snow as of early Monday afternoon.

The 13-inch total came from Kimball, near St. Cloud. Dr. Bob Weisman at St. Cloud State University had reported 7 inches of snow. Meteorologist reported 8.5 inches of snow had fallen in Forest Lake, Minnesota, a far northern suburb of the Twin Cities, as of 2 p.m. Monday.

Up to 9 inches of snow blanketed parts of southern and eastern Montana, including Red Lodge (9 inches), Glasgow (6 inches) and Glendive (4 inches). The Whitefish Ski Resort's Big Mountain Summit tallied 14 inches of snow in far northwest Montana. Drifts up to 2 feet around buildings were observed near Brusett, in northeast Montana.

Timing

- Monday: Snow will continue across much of South Dakota and central Minnesota during the day while expanding eastward rapidly across the northern half of Wisconsin during the morning and into Upper Michigan and parts of northern Lower Michigan in the afternoon. Winds of 15 to 30 mph may cause areas of blowing and drifting snow in open areas.

Meanwhile, snow tapers off in Montana while shifting southeast across Wyoming and parts of northern Colorado, especially east of the Continental Divide, but tapering off later in the day there.

- Monday night: Snow will taper off across South Dakota but a wind-driven snow, heavy at times, will continue farther east across central and southern Minnesota, possibly grazing northern Iowa, into northern Wisconsin and Upper Michigan. Parts of northern Michigan on either side of the Mackinac Straits may change over to rain as the low-pressure system draws warmer air north.

- Tuesday: Heavy snow will continue, mainly in northern Wisconsin and the Upper Peninsula of Michigan. Snow will taper off in eastern Minnesota in the morning. Some wrap-around snow may pivot into parts of southern Wisconsin and Lower Michigan. Bands of heavy lake-effect snow will kick in over the Upper Peninsula and northern Lower Michigan snowbelts by Tuesday evening.

How Much Snow?

The maps at right illustrate the current snowfall accumulation forecast. (Note these maps indicate additional accumulations going forward, on top of what has already fallen.)

In general, a roughly east-west swath from South Dakota through central Minnesota, northern Wisconsin and northern Michigan has the highest potential of seeing six inches or more of snow. Over a foot of snow is possible within that zone, especially east of the Mississippi River.

Surrounding that area to the north and south will be lighter amounts, where an inch or more of snow is possible.

Winter storm warnings are in effect for parts of seven states from the northern Rockies to the northern Great Lakes. As of Monday morning, these winter storm warnings encompassed a population of roughly 6 million, according to winter weather expert, .

Impacts

- Interstates that will become snow-covered and slippery Monday morning include stretches of I-90, I-94, I-35 and I-29 in parts of Minnesota, the Dakotas, northern Wyoming and Montana. Some blowing snow may reduce visibility, particularly in rural areas. Road conditions may worsen rapidly in the Twin Cities metro area as heavy snow moves in during the morning rush hour.

- The Monday afternoon/evening commute may become difficult in parts of northern Michigan, Wisconsin, southern Minnesota and South Dakota, in particular, due to falling and accumulated snow. Some blowing snow may reduce visibility.

- Flight delays and cancellations Monday are probable at Minneapolis/St. Paul, and low clouds well as Chicago O'Hare & Midway (low clouds near the warm front).

- Tuesday, any drizzle or light rain that had coated roads from parts of Iowa and southern Wisconsin to Indiana may freeze as the arctic front plunges south. Snow-covered roads will still be a problem in northern Michigan and Wisconsin along with additional blowing, drifting, and accumulating snow. Flight delays are also possible at Chicago O'Hare and Midway from strong winds.