A very unusual snow event unfolded across portions of south central and east central Minnesota, as well as west central Wisconsin on the evening of Wednesday, May 1st. Snowfall amounts topped over a foot of snow, with locally 12 to 15 inches in a small band near River Falls, Baldwin, Rice Lake and Ladysmith, Wisconsin, by the time the snow tapered off early Thursday afternoon, May 2nd.
This system was highly unusual due to the fact that May snowfall amounts average less than an inch. A strong Canadian air mass for early May allowed for critical temperatures to lower enough to produce snow across south central and east central Minnesota during the late afternoon and early evening of Wednesday May 1st. Areas around Chippewa Falls, and Eau Clairie, Wisconsin, were warmer initially, which kept this area in a mixture of sleet and rain, before changing over to all snow by Thursday morning, May 2nd.
A strong surge of moisture from the gulf interacted with the cold air mass to produce very heavy snowfall from Wednesday evening, through Thursday morning, before tapering off after 12 pm. Snowfall rates were as high as 1-2 inches per hour during the height of the storm. The following are some of the higher snowfall totals, ending Thursday afternoon, May 2nd.
Near Ladysmith 15.0 inches|Rice Lake 14.0 inches. |Weyerhaeuser 14.0 inches. |River Falls 13.0 inches. |Baldwin 12.0 inches. |Jim Falls 11.4 inches. |Durand 10.5 inches.
Both Ladysmith, and River Falls, broke the 24 hour, calendar day state record of 12.0 inches for the most snowfall in May. Both these sites beat the previous Wisconsin state daily record in May of 10.9 inches.
Due to the heavy snowfall and high liquid water content, large tree branches broke off and caused damage to power lines, along with numerous power outages.
Highland Ridge Campground at the Eau Galle Dam and Recreation Site, located in Spring Valley, Wisconsin, had excessive storm damage due to the extremely wet, and heavy snowfall.