Heavy, wet snow accumulated to 3 to 6 inches over much of southern Wisconsin as surface low pressure tracked across Illinois. Strong warm-air advection led to strong frontogenetic forcing over the region, with lift enhanced by differential positive vorticity advection associated with a 500-mb short-wave trough that crossed the region.
Every event with a place to put it; 14 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.
Heavy, wet snow accumulated to 3 to 6 inches over much of southern Wisconsin as surface low pressure tracked across Illinois. Strong warm-air advection led to strong frontogenetic forcing over the region, with lift enhanced by differential positive vorticity advection associated with a 500-mb short-wave trough that crossed the region. These features produced a steady, long-term snowfall that began in the early evening of the 23rd and lasted until the early morning hours of the 24th. A few locations (West Bend to Mt. Mary College in Milwaukee and from Burlington to the city of Racine) received between 7 to 8 inches of accumulation, but these higher amounts were isolated and had a low impact on travel. Therefore, this event was not documented as a winter storm.
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 Feb 23, 3:46 PM CST, 2 hours 14 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
346 PM CST THU FEB 23 2012
.TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS HIGH.
STILL LOOKS LIKE SNOW MOVING IN THIS EVENING...PERSISTING INTO
FRIDAY MORNING. MAIN CHANGES TO PREVIOUS FORECAST IS TO SLOW
THINGS DOWN A BIT MORE...AND ALSO BUMPED AMOUNTS UP A TOUCH.
EXPECTING SFC LOW TO SLIDE BY WELL SOUTHEAST OF WISCONSIN THIS
EVENING. LOW AT 700 MB TO GO ALONG WI/IL BORDER THOUGH...A GOOD
POSITION FOR ACCUMULATING SNOW IN THE SOUTH. STILL SEEING PRETTY
GOOD ISENTROPIC LIFT AND DEEP Q-VECTOR CONVERGE WITH THIS
SYSTEM...WITH A GOOD AMOUNT OF OMEGA IN THE DENDRITE ZONE.
FRONTOGENETIC FORCING QUITE GOOD AS WELL.
BEST FORCING REMAINS TOWARD THE ILLINOIS BORDER...WHERE SNOW COULD
BECOME HEAVY FOR A TIME. WITH MODELS TRENDING A BIT WETTER...WOUND
UP WITH HIGHER SNOW TOTALS. ENOUGH OF A CHANGE TO ADD
GREEN...LAFAYETTE...WAUKESHA...AND MILWAUKEE COUNTIES TO THE
ADVISORY. COULD EVEN SEE A LITTLE LAKE ENHANCEMENT IN THE
SOUTHEAST...AS NORTHEAST FLOW COMBINES WITH SFC-850 MB DELTA T
VALUES RISING TO 11-12C. ENHANCEMENT WOULD BE RELATIVELY BRIEF
THOUGH AS WINDS SHIFT TO THE NORTH AND THEN NORTHWEST LATER
TONIGHT INTO FRIDAY.
LINGERING SATURATION AND WEAK LIFT LATER FRIDAY MORNING AND INTO
THE AFTERNOON...SO KEPT SNOW CHANCES THROUGH THE DAY. CLOUDS AND
COLDER AIR BEHIND THIS SYSTEM WILL RESULT IN COLDER TEMPS
FRIDAY...THOUGH NEAR NORMAL FOR LATE FEBRUARY.
.FRIDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
THE SURFACE LOW CONTINUES TO MOVE WELL OFF TO THE EAST...BUT THE
FLOW ALOFT REMAINS CYCLONIC WITH ANOTHER SHORT WAVE MOVING THROUGH
FROM NORTHWEST TO SOUTHEAST. THINK THIS WILL BRING THE BEST CHANCE
FOR ANY LIGHT MEASURABLE PRECIP TO THE NORTHEAST PART OF THE
FORECAST AREA. EXPECT ONLY FLURRIES FOR THE SOUTHWEST FORECAST
AREA...FROM ABOUT MADISON ON SOUTHWEST. CLOUDS THROUGH THE NIGHT
SHOULD MODERATE HOW FAR THE TEMPS DROP.
.SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
RIDGING ARRIVES WITH CLEARING SKIES BY SATURDAY AFTERNOON. LOOKS
LIKE DECENT SUNSHINE...BUT TEMPS WILL ONLY REACH AROUND 30. TEMPS
SATURDAY NIGHT SHOULD EXHIBIT A NON-DIURNAL CURVE AS CLEAR SKIES
AND LIGHT WINDS WILL ALLOW TEMPS TO RADIATE OUT QUICKLY. THEN
HIGH/MID CLOUDS ROLL IN BY MIDNIGHT AHEAD OF THE NEXT BIG LOW
CHURNING OVER THE CENTRAL PLAINS...PUTTING A STOP TO THE TEMP
DROP...FOLLOWED BY LATE NIGHT WARM AIR ADVECTION.
.SUNDAY AND SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
STILL FOLLOWING THE NEXT BIG LOW TO MOVE THROUGH THE REGION DURING
THIS PERIOD. IT CONTINUES TO TAKE A NORTHERN TRACK ACROSS
NORTHWEST WISCONSIN. MOST OF THE PRECIP WILL BE NORTH OF THE
FORECAST AREA...BUT WILL HANG ONTO CHCY POPS. ALSO...WARM SECTOR
SNEAKS UP HERE WHICH WILL BRING A WINTRY MIX...CHANGING OVER TO
RAIN...THEN BACK TO A MIX BEFORE ENDING. THIS SHOULD HAVE LITTLE
IMPACT DOWN ACROSS SOUTHERN WISCONSIN.
.MONDAY AND MONDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
HIGH PRESSURE THIS PERIOD...SO QUIET WITH SEASONABLE TEMPS.
.TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
THIS IS OUR NEXT ACTIVE LOOKING PERIOD. BOTH THE GFS AND THE ECMWF
BRING A STRONG LOW UP INTO THE SOUTHERN GREAT LAKES LATER TUESDAY
NIGHT INTO WEDNESDAY. POSITION AND THERMAL PROFILE ARE OUT OF
SYNC...BUT THIS IS A LONG WAY OUT YET. THIS ONE COULD HAVE IMPACT.
&&
.AVIATION/00Z TAFS/...
STILL LOOKS LIKE SNOW MOVING IN THIS EVENING...PERSISTING INTO
FRIDAY MORNING. NOT MUCH HAS CHANGED SINCE PREVIOUS
FORECAST...WITH TOTAL AMOUNTS RANGING FROM 1 TO 2 INCHES IN THE
NORTH...TO 3 TO 5 IN THE SOUTH. THINKING AROUND 2 TO 4 INCHES FROM
MADISON TO MILWAUKEE.
CIGS LIKELY WILL FALL TO MVFR...PROBABLY EVEN IFR FOR A TIME AS
SNOW MOVES IN. VSBYS WILL HANG AROUND 1 MILE DURING THE BRUNT OF
THE SYSTEM...THOUGH STRONG FORCING MAY RESULT IN BURSTS OF 1/4
MILE SNOW...PARTICULARLY TOWARD THE ILLINOIS BORDER.
THE BULK OF ACCUMULATING SNOW WILL WIND DOWN FRIDAY MORNING...BUT
LINGERING SATURATION AND WEAK LIFT MAY KEEP LIGHT SNOW GOING
THROUGH MUCH OF THE DAY...ESPECIALLY IN THE EAST. CONDITIONS WILL
IMPROVE TOMORROW...BUT WILL PROBABLY STAY MVFR THROUGH THE DAY.
&&
.MARINE...
INCREASING NORTHEAST WINDS THIS EVENING...EVENTUALLY TURNING
NORTHERLY LATER TONIGHT...WILL GUST TO 25 KNOTS AT TIMES.
ADDITIONALLY...WAVES WILL BUILD TO 4 TO 6 FEET TONIGHT. THUS THE
SMALL CRAFT ADVISORY REMAINS UNCHANGED...GOING FROM THIS EVENING
INTO FRIDAY AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CST FRIDAY FOR WIZ067>072.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST
FRIDAY FOR WIZ065-066.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM CST FRIDAY FOR LMZ643>646.
&&
TONIGHT/FRIDAY AND AVIATION/MARINE...DDV
FRIDAY NIGHT THROUGH THURSDAY...DAVISHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 351 PM CST THU FEB 23 2012 WIZ046-047-051-052-056>060-062>072-241115- MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE- WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE- LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA- 351 PM CST THU FEB 23 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN. .DAY ONE...TONIGHT A WINTER WEATHER ADVISORY IS IN EFFECT TONIGHT FOR LAFAYETTE...GREEN...ROCK...WALWORTH...RACINE AND KENOSHA COUNTIES. A WINTER WEATHER ADVISORY GOES INTO EFFECT AT 9 PM CST THIS EVENING FOR MILWAUKEE AND WAUKESHA COUNTIES. SNOW ACCUMULATION OF 3 TO 5 INCHES IS EXPECTED IN THESE AREAS...WITH AMOUNTS UP TO 6 INCHES POSSIBLE IN KENOSHA COUNTY NEAR THE WISCONSIN AND ILLINOIS BORDER. ELSEWHERE ACROSS SOUTHERN WISCONSIN...SNOW ACCUMULATION OF 1 TO 3 INCHES IS EXPECTED. ROADS WILL BECOME SNOW COVERED AND SLIPPERY TONIGHT. THE SNOW IS A RESULT OF A STRONG UPPER LEVEL DISTURBANCE MOVING ACROSS NORTHERN ILLINOIS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THE WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM CST FRIDAY MORNING FOR THE AREAS PREVIOUSLY MENTIONED. THE SNOW WILL TAPER OFF TO SCATTERED LIGHT SNOW SHOWERS THROUGH THE REST OF FRIDAY. VERY WINDY CONDITIONS ARE LIKELY SUNDAY INTO MONDAY...AS STRONG LOW PRESSURE TRACKS FROM THE DAKOTAS NORTHEAST TO LAKE SUPERIOR...AND THEN INTO CANADA. A WIND ADVISORY MAY BE NEEDED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED IN THE NEXT SEVEN DAYS...HOWEVER SNOWFALL REPORTS ARE APPRECIATED. LMZ643>646-241115- SHEBOYGAN TO PORT WASHINGTON WI- PORT WASHINGTON TO NORTH POINT LIGHT WI- NORTH POINT LIGHT TO WIND POINT WI- WIND POINT WI TO WINTHROP HARBOR IL- 351 PM CST THU FEB 23 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN. .DAY ONE...TONIGHT A SMALL CRAFT ADVISORY IS IN EFFECT TONIGHT FOR BRISK NORTH WINDS AND HIGH WAVES...DUE TO STRONG LOW PRESSURE TRACKING FROM THE MIDDLE MISSISSIPPI RIVER VALLEY TO NEAR DETROIT. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY A SMALL CRAFT ADVISORY CONTINUES UNTIL MID AFTERNOON ON FRIDAY...FOR BRISK NORTHWEST WINDS AND LINGERING HIGH WAVES ASSOCIATED WITH THE PASSING LOW. GALE FORCE WINDS MAY THEN OCCUR FOR SUNDAY INTO MONDAY...AS STRONG LOW PRESSURE TRACKS FROM THE DAKOTAS NORTHEAST THROUGH LAKE SUPERIOR AND INTO CANADA. DAVIS/WOOD WWW.WEATHER.GOV/MKX
The national radar mosaic for the moment the first event began.
14 winter weather. Local standard time, as filed.
A co-operative observer at the Hustisford Waste Water treatment plant reported 3.5 inches of new snowfall.
A co-operative observer in Germantown reported 7.8 inches of new snowfall. A 47-year-old male from Hartford was killed when his vehicle was struck by a train. Police say slippery roads and limited visibility due to snow and ice covering the windshield contributed to the fatal accident.
A co-operative observer in Cedarburg reported 7 inches of new snowfall.
A co-operative observer in Cedarburg reported 7 inches of new snowfall.
A co-operative observer at Charmony Farm near Madison reported 4.6 inches of new snowfall.
A co-operative observer in Lake Mills reported 8.1 inches of new snowfall.
A co-operative observer south of Oconomowoc reported 5.8 inches of new snowfall.
A co-operative observer at Mount Mary College in Milwaukee reported 7.9 inches of new snowfall.
A co-operative observer 4 miles southwest of Wayne reported 5.9 inches of new snowfall.
A co-operative observer in Monroe reported 5.0 inches of new snowfall.
Co-operative observers at Evansville and Afton both reported 6.0 inches of new snowfall.
A co-operative observer in Lake Geneva reported 4.8 inches of new snowfall.
A trained spotter 2 miles northeast of Sturtevant reported 8.3 inches of new snowfall.
A co-operative obsever in Paddock Lake reported 8.0 inches of new snowfall.
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, Washington | 2012-02-24 | 47 | Male | Vehicle/Towed Trailer | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2012Every state in 2012This day in weather historyWarnings in Wisconsin, February 2012
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 2026-09-24. Each event’s entry at NCEI: 367510, 367516, 367517, 367541, 367542, 367543, 367544, 367545, 367546, 367547, 367548, 367550, 367551, 367552.