The preceding radar animation shows the most important feature of this storm. The loop is valid ending at 06:40 UTC or 12:40 AM CST March 12, 2023. Two upper-level shortwave troughs appeared to be embedded within the larger storm circulation. The leading trough looks as if it is inducing a circulation over the head of Lake Superior. The circulation intensified as the shortwave moved over the area. Also notice the heavier snow extending northeast over the higher terrain of the North Shore of Lake Superior. Lift due to east winds into the ridge were enhancing the snow. Not unusual for orographic enhancement to occur in this type of scenario but this example is well defined.
The snowstorm started in earnest late morning, March 11 and ending late evening, March 12. Heavy snow fell in conjunction with the passage of each shortwave shown on radar. Snowfall rates peaked around 2 inches per hour. Later in the storm a strong lake-effect snow band produced a brief shot of heavy snow late morning into early afternoon, March 12. The following radar animation shows the band moving south through Duluth and the city of Superior in Wisconsin. Snow totals for the storm ranged from 10 to 16 inches across most of Duluth and the city of Superior, WI. The National Weather Service Forecast Office in Duluth reported 12.5 inches. Personal measurement was 14.3 inches.
Notice the winds in the atmosphere over Lake Superior and Northeast Minnesota are from the east to southeast from the surface to 700 millibars (mb).
Surface analysis - NOAA NWS Weather Prediction Center
7 PM CDT Saturday March 11, 2023 (00 UTC March 12)
Surface analysis - NOAA NWS Weather Prediction Center
1 AM CDT Sunday March 12, 2023 (06 UTC March 12)
925 mb analysis - NOAA NWS Storm Prediction Center
7 PM CDT Saturday March 11, 2023 (00 UTC March 12)
850 mb analysis - NOAA NWS Storm Prediction Center
7 PM CDT Saturday March 11, 2023 (00 UTC March 12)
700 mb analysis - NOAA NWS Storm Prediction Center
7 PM CDT Saturday March 11, 2023 (00 UTC March 12)
500 mb analysis - NOAA NWS Storm Prediction Center
7 PM CDT Saturday March 11, 2023 (00 UTC March 12)
300 mb analysis - NOAA NWS Storm Prediction Center
7 PM CDT Saturday March 11, 2023 (00 UTC March 12)