Wintry scene in Maplewood with falling snow and reduced visibility during the morning of Thursday December 19, 2024. Courtesy Minnesota State Climatology Office.
A rather productive "Alberta Clipper" dropped more snow than is typical of systems originating in western Canada, leaving accumulations in excess of six inches in parts of central and southern Minnesota, and covering virtually all of the state with accumulating snow for the first time this winter.The snows began around midnight in western Minnesota, and then intensified and spread eastward and southeastward across the state through Thursday morning. One particularly heavy burst of snow worked northeastward from New Prague and Hutchinson before sunrise, and greeted Twin Cities area commuters with visibility of quarter-mile at time as the snow piled up rapidly. This heavier snow lingered in the eastern suburbs, leaving some higher snowfall totals there.The main area of snow moved into Wisconsin by noon, but small bands of accumulating snow continued tracking through northwestern, central and southern Minnesota through the evening. These snows were generally concentrated between the Mississippi and Minnesota rivers, reaching into Easterly winds off of Lake Superior also helped induce snowfall rates just inland and up-hill from the lake. Winds gusting to 35 mph at times produced significant blowing and drifting in open areas.Snowfall accumulations in the range of 6 to 8.5 inches followed an arcing northwest-to-southeast corridor, from near Moorhead and Fergus Fall, down to Gaylord, Elko, Northfield, Red Wing, Wabasha, and Rochester--including the western and southern Twin Cities area. A smaller patch of higher accumulations followed I-694 in Ramsey County.The highest snowfall total reported by an official National Weather Service cooperative observer was 8.1 inches near Minnesota City, just upriver from Winona. CoCoRaHS volunteer observer reports included 8.7 inches near Bird Island; 8.3 inches at Elko; 8.1 inches near Prior Lake and Northfield; and 8.0 inches near Le Center and Rochester. Observations at Minnesota's first-order climate stations near the airports included 7.5 inches at Rochester, 5.5 inches in the Twin Cities, 4.0 inches at St. Cloud, and 2.7 inches at Duluth.Snows were even heavier in Wisconsin, where some totals reached double digits in the south, central, and east.
Not a Record Clipper, But a Big One!
Total precipitation in the heaviest snow was generally between 0.30 and 0.50 inches, with a smattering of higher totals. While neither the peak snowfall amounts, nor the precipitation, represent extremes for winter events in Minnesota, both are quite high for the
type of weather system that produced them. This was an "Alberta Clipper" (or simply "Clipper") system, originating in the prairies of southwestern Canada before moving east-southeastward across the northern Rockies, western North Dakota, northeastern South Dakota, and southern Minnesota. Clipper systems typically produce powdery snow, strong winds, and falling temperatures. Precipitation is usually less than a quarter-inch, and accumulations tend to be 1-4 inches. Thanks to the abundant moisture and broad area of strong lift, this ended up being one of the wetter and snowier clipper-type systems known to Minnesota. The snowfall totals were a shade lower than those of the
"Super Clipper" of January 2022, and were no match for the other-worldly
"Super-Duper Clipper" of March 2023, but this certainly was one of the top snow-producing clippers on record in Minnesota.Posted December 20, 2024KAB
