February 21-23, 2022 Winter Storm

A long-duration winter storm brought widespread snowfall amounts of 6 to 12 inches across parts of northeast Minnesota and northwest Wisconsin. Areas around Lake Superior received over a foot of snow, and over two feet of snow fell in parts of northern Bayfield and Ashland counties.

With low level winds out of the east-northeast and much of the Lake Superior ice-free away from shorelines, lake-enhanced bands of snow developed at times across western Lake Superior communities. In particular, a very narrow lake-enhanced band of snow developed near Washburn, WI (south of Bayfield, WI), which contributed to snowfall amounts as high as 33.5" falling across the long duration storm. Late Monday into Tuesday Feb 22, an area of low pressure deepened across the Mid-Mississippi River Valley, which then tracked northeast towards the Lower Great Lakes on Tuesday Feb 22. Finally, an Arctic high pressure over the Canadian Prairies spread southward into the northern Great Plains and into the Upper Midwest Tuesday night into the morning of Wed Feb 23.

The storm resulted in a long period of poor road conditions, with strong winds causing blowing and drifting snow. Winds consistently gusted over 40 mph at the Duluth Sky Harbor airport on Monday, February 21 between 6:00 am through 6:00 pm, and other observation sites around western Lake Superior reported similar high winds. Peak wind gusts through this storm included 54 mph at the Bay of Grand Marais, 53 mph at Duluth Sky Harbor airport, and 51 mph at the Devils Island lighthouse (part of the Apostle Islands). 

Impacts from this storm were numerous, with most area school districts closed on Tuesday, February 22. (Most were already closed on Monday, February 21 due to the federal holiday; Duluth Public Schools were on a planned winter recess during the entire week). The City of Duluth issued only the second  Snow Emergency  in city history, requiring vehicles along Snow Emergency Routes to be moved. Other communities including Brainerd, MN, Ashland, WI, and Washburn, WI also issued Snow Emergencies. Vehicle crashes on both the Blatnik and Bong bridges between Duluth and Superior caused brief closures at times on Monday due to the near whiteout conditions and heavy snowfall rates. US Highway 2 in Ashland was also closed late Monday night through Tuesday evening due to the strong winds causing blowing and drifting - a rare but not unusual closure where the highway runs along the lakeshore.

Moisture with this system was not incredibly anomalous, which is why most areas saw moderate snowfall accumulations that added up over several days. Since the low pressure system was displaced well to the south of the upper Midwest, the highest synoptic moisture was contained away from northern Wisconsin. Nevertheless, there was plenty of synoptic forcing to squeeze out much of the moisture that was in place.

A nearly zonal 500 hPa flow on February 21 became more southwest-to-northeasterly by February 23 with an upper level trough deepening. This helped to strengthen the surface low and attendant mid-level frontogenesis that caused snowfall over northwest Wisconsin.

A 300 hPa jet max located roughly over Lake Superior at the start of the storm likely enhanced the lift associated with frontogenesis and warm air advection in the mid-levels. The discussion thus far has focused on synoptic and mesoscale forcing mechanisms that contributed to heavy snowfall, but lake-enhancement was also a major contributor to the heaviest snowfall totals over the Bayfield Peninsula.