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.

Winter Storm in PIERCE, WISCONSIN
From 01-MAY-13 17:00:00 to 02-MAY-13 08:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 6 to 13 inches across the county with the heaviest near Spring Valley and River Falls, which both measured 13.0 inches.

Winter Storm in BARRON, WISCONSIN
From 01-MAY-13 20:00:00 to 02-MAY-13 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 12 to 14 inches across the county with the heaviest around Rice Lake which measured 14.0 inches.

Winter Storm in DUNN, WISCONSIN
From 01-MAY-13 20:00:00 to 02-MAY-13 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts averaged around 12 inches across the county.

Winter Storm in PEPIN, WISCONSIN
From 01-MAY-13 20:00:00 to 02-MAY-13 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts averaged around 10 inches across the county with the heaviest near Durand which measured 10.5 inches.

Winter Storm in RUSK, WISCONSIN
From 01-MAY-13 20:00:00 to 02-MAY-13 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 8 to 15 inches across the county with the heaviest around Ladysmith which measured 15.0 inches.

Winter Storm in CHIPPEWA, WISCONSIN
From 02-MAY-13 06:00:00 to 02-MAY-13 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 9 to 11 inches across the county with the heaviest around Jim Falls which measured 11.4 inches. Due to the heavy snowfall, roadways in the north part of the county were obstructed by trees in vicinity of County Highway 40 & County Highway M.

Winter Storm in EAU CLAIRE, WISCONSIN
From 02-MAY-13 06:00:00 to 02-MAY-13 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 7 to 10 inches across the county with the heaviest around Eau Claire.  In Eau Claire, 8.7 inches fell on May 2nd, which broke the record May snowfall at the WQOW TV.  In addition, Eau Claire Airport had a record daily cold high temperature for the day of 34 degrees.

Winter Storm in POLK, WISCONSIN
From 01-MAY-13 17:00:00 to 02-MAY-13 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 6 to 10 inches across eastern Polk County with locally heavier amounts near Clear Lake, Wisconsin.

Winter Storm in ST. CROIX, WISCONSIN
From 01-MAY-13 17:00:00 to 02-MAY-13 06:00:00 (CST-6)
Property damage: 50.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snowfall amounts ranged from 6 to 12 inches across the county with the heaviest near Baldwin which measured 12.0 inches.  Highland Ridge Campground at the Eau Galle Dam and Recreation Site, located north of Spring Valley, Wisconsin, had excessive storm damage due to the extremely wet, and heavy snowfall.