Heavy Snow and Thundersnow
April 11 to 13, 2013
Snow fell over a prolonged period from 10:25 AM CST (11:25 AM CDT) April 11th to 8 AM CST (9 AM CDT) April 13th. The heaviest snow fell very early in the storm from 11 AM to 3 PM CST April 13th with snowfall rates of an inch or more per our 11 AM to 1 PM. Thundersnow produced several brief but very intense bursts of snow. At one point in time the sky became so dark that some of the street lights came on. The radar loop below shows the convective/cellular structure of the snow. A personal observation of thunder was made 15 minutes prior to the start time of the loop. Note that the loop shows time in UTC and CDT. In total, this observer heard thunder at the following times: 11 AM CST, 11:40 AM CST, 11:45 AM CST, and 12:35 PM CST.
Fairly strong winds accompanied the first half of the event creating a dense snowpack. Winds occasionally gusted over 40 mph into the early morning hours beyond midnight April 12th. Peak wind reported from the observing equipment at the Duluth International Airport was 48 mph from an 80 degree direction (East) on April 11th.
Snow Totals: DAK (myself) 13.9 NWS Duluth 13.3
Storm images from the National Weather Service Doppler Radar, Duluth, MN