Low pressure, driven by a vorticity maximum that moved across central and southern sections of Wisconsin, tracked across northern Illinois. Snow began falling early in the morning of the 17th with warm air advection ahead of the system, and continued through the day as the system moved through.
Every event with a place to put it; 20 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MKX wrote it up.
Low pressure, driven by a vorticity maximum that moved across central and southern sections of Wisconsin, tracked across northern Illinois. Snow began falling early in the morning of the 17th with warm air advection ahead of the system, and continued through the day as the system moved through. Snow totals of 3 to 6 inches were widespread across South Central and Southeast Wisconsin, with a few locations receiving more than 6 inches of snow over the nearly 18-hour event. Winds of 10 to 20 mph, with gusts to 30 mph, reduced visibilities with blowing and drifting snow. Numerous accidents were reported across southern Wisconsin. A semi-trailer truck slid off the Interstate 90-94 bridge over Mirror Lake, killing (indirectly-related) the driver and critically injuring (indirectly-related) a passenger. The accident closed westbound lanes of the interstate for a time, with traffic reduced to one lane for days afterward until authorities could examine damage to the bridge and deem it safe for regular traffic flow.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Milwaukee, WI wrote its last area forecast discussion before the first event at Jan 17, 4:44 AM CST, 1 hour 16 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
20 winter weather. Local standard time, as filed.
Snowfall totals over a near 18-hour period ranged from 3 to 4 inches, with winds gusting to 25 and 30 mph at times reducing visibilities to under a mile in blowing and drifting snow.
Snowfall totals over a near 18-hour period ranged from 3 to 4 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Markesan measured 4.1 inches of snow.
Snowfall totals over a near 18-hour period ranged from 4 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. Coop observers near Fond Du Lac and Campbellsport both measured 5.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 4 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer just southwest of Sheboygan measured 5.5 inches of snow. Many vehicles slid off snow-covered roads, with one accident on STH 144 in the Town of Scott causing 2 minor injuries.
Snowfall totals over a near 18-hour period ranged from 3 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A semi-trailer truck slid off the Interstate 90-94 bridge over Mirror Lake. The driver was killed and a passenger was critically injured in the accident. A coop observer near La Valle measured 5.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Portage measured 5.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Beaver Dam measured 5.1 inches of snow.
Snowfall totals over a near 18-hour period ranged from 4 to 7 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. The coop observer in Jackson measured 6.5 inches of snow.
Snowfall totals over a near 18-hour period ranged from 4 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. The coop observer in Port Washington measured 6.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. The coop observer in Mineral Point measured 5.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. The coop observer in Mount Horeb measured 5.5 inches of snow. A 57-year-old Madison man with a history of heart problems died while shoveling snow on the far west side of Madison. Numerous accidents and slide offs were reported by both the Madison Police Department and the Dane County Sheriff.
Snowfall totals over a near 18-hour period ranged from 3 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. An NWS employee southeast of Palmyra measured 6.0 inches of snow. Numerous accidents were reported due to slick, snow covered roads. A 24-year-old man was injured when his car slid under a semi-trailer truck that had pulled out in front of him on U.S. Highway 12 and STH 26. Three people were injured when a northbound car on STH 26 in the Town of Watertown slid into the opposite lane, skidding head-on into another car carrying two passengers. The injuries were not life-threatening.
Snowfall totals over a near 18-hour period ranged from 3 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. An NWS employee south of Oconomowoc and a coop observer in Sussex both measured 5.7 inches of snow. The Waukesha County Sheriff's Department reported 103 vehicles in ditches, and 81 accidents.
Snowfall totals over a near 18-hour period ranged from 3 to 9 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Wauwatosa measured 8.5 inches of snow.
Snowfall totals over a near 18-hour period ranged from 4 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Blanchardville measured 6.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Brodhead measured 5.7 inches of snow. Numerous accidents and spinouts were reported by police officials across the county. The driver of a vehicle that was westbound on STH 59 in the Town of Albany was injured when the car slid off the road into a ditch and struck a tree.
Snowfall totals over a near 18-hour period ranged from 4 to 7 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Afton measured 7.0 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Delavan measured 4.9 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 6 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Wind Point measured 5.5 inches of snow.
Snowfall totals over a near 18-hour period ranged from 3 to 5 inches, with winds gusting to 30 mph at times reducing visibilities to under a mile in blowing and drifting snow. A coop observer in Paddock Lake measured 5.3 inches of snow.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Winter Weather, Sauk | 2011-01-17 | 43 | Male | Vehicle/Towed Trailer | Indirect |
| Winter Weather, Dane | 2011-01-17 | 57 | Male | Outside/Open Areas | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2011Every state in 2011This day in weather historyWarnings in Wisconsin, January 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-30. Each event’s entry at NCEI: 277535, 277536, 277537, 277538, 277539, 277540, 277541, 277542, 277543, 277544, 277545, 277546, 277547, 277548, 277549, 277551, 277552, 277553, 277554, 277555.