Sloppy Winter Storm, January 14-15, 2021

snow map
Map of snowfall totals from Jan 14-15, 2021.
Courtesy: National Weather Service - Twin Cities/Chanhassen

An unusually warm winter storm produced an expansive mass of rain and wet snow, mucking up roads and leaving behind treacherous ruts and mats of crusted slush across much of Minnesota.

The winter storm formed as a low pressure system followed an unlikely path and life-cycle, originating deep in the Canadian prairies, and then plunging southeastward across Minnesota, before stalling and intensifying over southern Wisconsin. Most of the precipitation formed as the system was southeast of Minnesota, with bands of snow spiraling westward into the state.

Although the storm had been forecast to produce widespread heavy snowfall totals, along with blizzard conditions in southwestern Minnesota, the lack of cold air plagued it from the start. Thus, while much of Minnesota braced for another high-impact winter storm, temperatures at or above freezing produced a wetter-than-expected snow that was slow to accumulate and resisted blowing and drifting. Blizzard conditions never materialized anywhere in Minnesota, and accumulations were held to 1-4 inches over most of the state, with only small areas of  5-8 inches scattered among far-southern areas.

The impacts were different than expected as a result. Instead of large, wind-swept snowdrifts engulfing vehicles across the state's open areas, Minnesotans were treated to a few inches of slushy accumulations that compacted quickly and transformed into icy sheets as temperatures fell below freezing in the days after the storm. 

Snowfall totals reported in Minnesota included 8.3 inches near Ellendale, measured by a CoCoRaHS observer; 7.5 inches near the Worthington airport; 6.5 inches measured by the Cooperative National Weather Service observer in Owatonna; and 4.6 inches in Rochester. The Twin Cities recorded 2.9 inches officially, with the long-term stations at Duluth, St. Cloud, and International Falls all reporting around an inch-and-a-half. 

The wet nature of the snow led to very low snow-to-liquid ratios. January snowstorms often produce 15-25 times more measured snow than liquid, so that a tenth of an inch of precipitation yields 1.5 to 2.5 inches of snow. With this system, however, the high water content kept snow-to-liquid ratios around 7 or 8-to-1; each tenth of an inch of precipitation yielded just 0.7 or 0.8 inches of snow.


Modified: Jan 20, 2021

Back to top