Blizzard in Wisconsin, December 20 to 21, 2012

Name: Blizzard in Wisconsin, December 20 to 21, 2012
Start: 2012-12-20T10:00
End: 2012-12-21T00:39
Location: Wisconsin

December 20 to 21, 2012 · NWS MKX · 11 events in 11 counties and zones

A blizzard brought record double-digit snowfall to much of South-Central and a portion of Southeast Wisconsin. bringing near-zero visibilities and severe drifting across the region.

Where it happened

Every event with a place to put it; 11 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 11

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.

What happened

The episode as NWS MKX wrote it up.

A blizzard brought record double-digit snowfall to much of South-Central and a portion of Southeast Wisconsin. Winds gusted to between 40 and 48 mph during the peak of the storm...bringing near-zero visibilities and severe drifting across the region. Major highways as well as a majority of side roads became nearly impassible as plowing operations were greatly limited, or completely suspended as plows became stuck in the heavy, wet, drifting snow. Area airports suspended all flight operations. A maximum wind gust of 48 mph (42 knots) was measured at the Monroe Airport in Green County. A new daily snowfall record was set at Madison Truax Field with 13.3 on calendar day December 20th (old record was 4.6 in 2000). This is the 2nd highest total for any single calendar day. The greatest calendar day snowfall in Madison was 17.3 inches on December 3, 1990. The UW-Arlington Experimental Farm in Columbia County measured 14.0 inches for the 24-hour period ending 700 AM CST December 21st, which tied the 1-Day snowfall record for that county. The 2-day (19) and 3-Day (21) at this location were new records. The 2-day (21.5) and 3-Day (21.8) snowfall totals in Mt. Horeb established new records for Dane County. The 2-day (20.5) and 3-Day (21.2) snowfall totals in Dodgeville established new records for Iowa County. The 2-day (20.1) and 3-Day (24.1) snowfall totals in the Town of Westford established new records for Dodge County. The 2-day (16.6) and 3-Day (18.2) snowfall totals in New Glarus established new records for Green County. Elsewhere in south-central and parts of Southeast Wisconsin several other sites were within 10% of their county's 1-Day, 2-Day and 3-day records. In addition to the heavy snow and near-zero visibilities, the strong gusty winds downed tree limbs and power lines, with utility companies reporting 34,500 customers without power at the height of the storm. This blizzard was triggered by a strong low pressure which tracked from southeast Kansas to near Chicago the evening of December 20th...reaching the southern tip of Lake Huron by the morning of December 21st. Warm air wrapping into the system initially brought rain into parts of south-central and southeast Wisconsin before changing over to all snow. A new daily precipitation record was set in Madison...1.16 inches of liquid equivalent precipitation on Thursday, December 20th, which broke the previous record of 0.80 inches, set in 1882.

What forecasters said that day

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 Dec 20, 4:32 AM CST, 5 hours 28 minutes earlier.

Area forecast discussion, Dec 20, 4:32 AM CST, 5 hours 28 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
432 AM CST THU DEC 20 2012

.UPDATE...

TODAY-FORECAST CONFIDENCE HIGH

RAIN/SNOW LINE ROUGHLY JANESVILLE TO WAUKESHA TO PORT
WASHINGTON...WITH 850 MB ZERO LINE PER LATEST RAP FROM JUST SOUTH
OF DBQ TO JVL AND RAC. THIS SHOWS UP WELL IN RADAR PRODUCTS AND
ESPECIALLY DUAL POL CC AND ZDR.

RAP HAS 850 MB ZERO LINE AND BASICALLY THE RAIN/SNOW LINE MOVING
TO ABOUT DARLINGTON TO WATERTOWN TO PORT WASHINGTON IN THE 15Z TO
18Z PERIOD. IT THEN SAGS BACK TO A MKE TO RFD LINE BY 21Z AND
CONTINUES TO COLLAPSE SOUTH THEREAFTER WITH SURFACE LOW HEADING
OVER LAKE MICHIGAN AND 700 MB LOW CONTINUING TO DEEPEN.

THERE WILL BE A LAG IN THE PRECIPITATION FOR A THIS MORNING...AND
MODELS HAVE BEEN CONSISTENT IN BRINGING A STRONG DEFORMATION BAND
THROUGH DURING THE AFTERNOON AND EVENING. THIS LOOKS VERY
CONVECTIVE AND YOU COULD EASILY SEE 2 TO 3 INCH PER HOUR
THUNDERSNOWS AS THE RAP SHOWS HOURLY PRECIP ALONG THE -2 TO -3 850
ISOTHERM IN 0.20 TO 0.30" RANGE.

RAIN SHOULD FALL NEAR LAKE MICHIGAN AND ESPECIALLY
MILWAUKEE...SOUTHEAST WAUKESHA...WALWORTH...RACINE...KENOSHA
COUNTIES MUCH OF THE DAY.

AS STRONG GRADIENT AND COLD ADVECTION PUSHES INTO THE NORTHWEST
HALF THIS AFTERNOON...EXPECT FALLING TEMPERATURES AND A DRIER SNOW
TO PILE UP...ALLOWING FOR BLIZZARD CONDITIONS AS THE WINDS GUST UP
TO 35 OR 40 KNOTS.

TONIGHT-FORECAST CONFIDENCE HIGH

COLD AIR PUSHES INTO THE SOUTHEAST AROUND RUSH HOUR WITH RAIN
TURNING OVER TO HEAVY WET SNOW. ALTHOUGH TOTAL SNOW AMOUNTS MAY
ONLY BE IN THE 3 TO 5 INCH RANGE...IT COULD MAINLY FALL IN A 2 TO
3 HOUR PERIOD WITH THUNDER AND INCREASING WINDS. SO WINTER STORM
WARNING WARRANTED DUE TO POTENTIAL IMPACT.

ELSEWHERE SNOW WILL START TO DIMINISH LATER ON BUT WINDS WILL BE
VERY STRONG AND SIGNIFICANT BLOWING AND DRIFTING EXPECTED OVER THE
WESTERN TWO-THIRDS OF THE AREA.

&&

.AVIATION/12Z TAFS/...

LIFR CONDITIONS EXPECTED FOR KMSN MOST OF THE DAY...WITH WINDS
PICKING UP IN THE AFTERNOON AND EVENING. SIGNIFICANT BLOWING SNOW
AND NEAR ZERO VISIBILITIES LIKELY.

IFR CONDITIONS WITH RAIN MKE AND ENW AND SNOW CHANGING TO RAIN
UES. DURING THE AFTERNOON AND EARLY EVENING EXPECT LIFR CONDITIONS
TO DEVELOP AS RAIN CHANGES OVER TO HEAVY WET SNOW AND VERY STRONG
NORTHWEST WINDS GUSTING TO 35 OR 40 KNOTS DEVELOPS.

&&

.MARINE...

NEAR GALE CONDITIONS TODAY TURNING TO STRONG GALE AND APPROACHING
STORM FORCE THIS EVENING AS LOW CROSSES SOUTHERN LAKE MICHIGAN AND
COLD AIR POURS IN FROM NORTH AND NORTHWEST. 850 MB WINDS INCREASE
TO 70 KNOTS IN THE EVENING AND ABOUT THE ONLY THING THAT WILL KEEP
STORM FORCE WINDS FROM OCCURRING IN NEAR SHORE WATERS IS
FRICTION FROM NORTHWEST WINDS COMING OFF LAND. WILL BE A CLOSE
CALL AND MAY NEED TO BE UPGRADED LATER.

&&

.PREV DISCUSSION... /ISSUED 330 AM CST THU DEC 20 2012/

FRIDAY - CONFIDENCE...MEDIUM
STRONGLY CYCLONIC FLOW PERSISTS IN THE MORNING WITH NVA WORKING IN
DURING THE AFTERNOON. TIGHT GRADIENT LINGERS FOR A TIME WITH 925
WINDS STILL RAMPED UP PRETTY GOOD AT 45-50 KNOTS. WILL PUT IN SOME
BLOWING SNOW TO COINCIDE WITH THE TIGHTER GRADIENT AND SUBSEQUENT
LINGERING STRONGER WIND FIELD. WENT WITH COLDER TEMPS DUE TO THE
FRESH SNOW COVER AND THIS WAS BEST HANDLED BY THE CONSENSUS BLEND
RATHER THAN THE BIAS CORRECTED NUMBERS.

SATURDAY - CONFIDENCE...MEDIUM
SURFACE RIDGE AXIS SLIDES ACROSS WITH A MUCH LIGHTER WIND REGIME.
UPPER FLOW BROADLY ANTICYCLONIC WITH HINTS OF A WEAK SHEARED VORT.
AIRMASS IS BONE DRY PER BUFKIT SOUNDINGS.

SUNDAY - CONFIDENCE...MEDIUM
HIGH PRESSURE CONTINUES TO BUILD IN WITH MID LEVEL RIDGING
DOMINATING. AIRMASS REMAINS DRY. 850 0C ISOTHERM NEAR THE WI/IL
BORDER.

MONDAY AND TUESDAY - CONFIDENCE...MEDIUM
PRETTY DECENT AGREEMENT AMONGST THE MODELS ON THE IDEA OF A
SHORTWAVE PROGRESSING FROM THE PLAINS TOWARDS THE UPPER MIDWEST
THOUGH TIMING AND PLACEMENT DETAILS ARE OFF AT THIS POINT. THE ECMWF
GETS A LITTLE MORE PHASING WITH A SOUTHERN STREAM WAVE AND BRINGS A
MORE DEVELOPED SURFACE LOW NORTHWARD WHILE OTHER MODELS SHOW A MORE
LOOSELY DEFINED INVERTED TROUGH. DESPITE THE TIMING AND STRUCTURE
DIFFERENCES...SOME LIGHT QPF NOTED.

WEDNESDAY - CONFIDENCE...LOW
MORE SIGGY PIECE OF ENERGY MOVES INTO THE CENTRAL PLAINS PER THE GFS
AND ECMWF. SUBSEQUENT CYCLOGENESIS IS HANDLED QUITE DIFFERENTLY
BETWEEN THE MODELS WITH THE ECMWF DEVELOPING A LOW IN THE SE US AND
THE GFS IN THE OH VALLEY. ALLBLEND POPS APPEAR TO BE GIVING A LITTLE
MORE WEIGHTING TO THE GFS POSITION OF LOW...WHICH TENDS TO MAKE MORE
SENSE GIVEN PROGGD LOCATION OF UPPER DYNAMICS.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WARNING UNTIL NOON CST TODAY FOR WIZ046-047-051-
     056>059-062>064-067>069.

     BLIZZARD WARNING FROM NOON TODAY TO MIDNIGHT CST TONIGHT FOR
     WIZ046-047-056-057-062-063-067-068.

     BLIZZARD WARNING FROM NOON TODAY TO 3 AM CST FRIDAY FOR WIZ051-
     058-059-064-069.

     WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 3 AM CST FRIDAY
     FOR WIZ066-071-072.

     WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 3 AM CST FRIDAY
     FOR WIZ052-060-065-070.

LM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR LMZ643>646.

     GALE WARNING FROM NOON TODAY TO NOON CST FRIDAY FOR LMZ643>646.

&&

UPDATE...CRAVEN
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
FRIDAY THROUGH WEDNESDAY...COLLAR

Hazardous weather outlook, Dec 20, 9:34 AM CST, 26 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
934 AM CST THU DEC 20 2012

WIZ046-047-051-052-056>060-062>072-211100-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
934 AM CST THU DEC 20 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

THE MAJOR WINTER STORM WILL CONTINUE THROUGH TONIGHT. A BLIZZARD
WARNING GOES INTO EFFECT THIS AFTERNOON FROM
JANESVILLE...JEFFERSON...WEST BEND...AND FOND DU LAC ON WEST. MORE
THAN A FOOT OF SNOW IS EXPECTED IN THIS AREA...WITH SIGNIFICANT
BLOWING AND DRIFTING SNOW.

WINTER STORM WARNINGS WILL BE IN EFFECT ELSEWHERE...ESPECIALLY
TONIGHT. 4 TO 8 INCHES OF HEAVY WET SNOW ARE ANTICIPATED. THE LOWEST
AMOUNTS ARE EXPECTED NEAR LAKE MICHIGAN...ESPECIALLY FROM MILWAUKEE
TO RACINE AND KENOSHA...WHERE RAIN IS EXPECTED MUCH OF THE TIME
TODAY.

ISOLATED THUNDERSTORMS WILL CONTINUE INTO THIS EVENING.

STRONG WINDS ON THE BACK SIDE OF THE STORM THIS AFTERNOON WILL BRING
BLIZZARD OR NEAR BLIZZARD CONDITIONS TO MOST AREAS. TRAVEL WILL
BECOME DIFFICULT TO IMPOSSIBLE. THIS WILL BE A CRIPPLING AND
LIFE-THREATENING WINTER STORM.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A COUPLE OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK INTO THE OHIO
VALLEY AREA MONDAY...AND AGAIN AROUND WEDNESDAY. ACCUMULATING SNOWS
ARE POSSIBLE WITH EACH LOW PRESSURE SYSTEM. IN ADDITION...NORTHEAST
WINDS AND COLD TEMPERATURES MAY ALLOW FOR LAKE EFFECT SNOWS DURING
THE PERIOD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED IN THE NEXT SEVEN
DAYS...HOWEVER SNOWFALL AND BLIZZARD CONDITION REPORTS WILL BE
APPRECIATED TODAY AND TONIGHT.

LMZ643>646-211100-
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-
934 AM CST THU DEC 20 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

RAPIDLY DEEPENING LOW PRESSURE MOVING THROUGH THE WESTERN GREAT
LAKES WILL BRING STRONG WINDS AND HIGH WAVES TO SOUTHERN LAKE
MICHIGAN TODAY INTO FRIDAY NIGHT. THE STRONGEST WINDS ARE EXPECTED
THROUGH FRIDAY. A GALE WARNING IS IN EFFECT. A STORM WARNING IS IN
EFFECT FOR THE OPEN WATERS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

GALE FORCE WINDS WILL DIMINISH BY FRIDAY EVENING...BUT BRISK WINDS
AND HIGH WAVES WILL CONTINUE INTO SATURDAY MORNING...AS LOW PRESSURE
SLOWLY MOVES ACROSS THE EASTERN GREAT LAKES TOWARD THE NORTHEAST.

CRAVEN/WOOD
WWW.WEATHER.GOV/MKX

In the hours before

Local storm report, Dec 20, 9:38 AM CST, 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
938 AM CST THU DEC 20 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0530 AM     SNOW             HARTFORD                43.32N 88.39W
12/20/2012  M4.2 INCH        WASHINGTON         WI   CO-OP OBSERVER

            4.2 INCHES STORM TOTAL.

0600 AM     SNOW             2 E HOLY HILL           43.24N 88.29W
12/20/2012  M5.9 INCH        WASHINGTON         WI   CO-OP OBSERVER

            5.9 INCHES STORM TOTAL.

0600 AM     HEAVY SNOW       WEST BEND               43.42N 88.18W
12/20/2012  E6.0 INCH        WASHINGTON         WI   PUBLIC

0600 AM     HEAVY SNOW       1 N BEAVER DAM          43.48N 88.84W
12/20/2012  M6.5 INCH        DODGE              WI   CO-OP OBSERVER

            6.5 INCHES STORM TOTAL.

0639 AM     SNOW             1 N MERTON              43.16N 88.31W
12/20/2012  M5.0 INCH        WAUKESHA           WI   CO-OP OBSERVER

            5.0 INCHES STORM TOTAL.

0700 AM     SNOW             GERMANTOWN              43.23N 88.10W
12/20/2012  M3.4 INCH        WASHINGTON         WI   CO-OP OBSERVER

            3.4 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       5 W CAMPBELLSPORT       43.60N 88.38W
12/20/2012  M6.0 INCH        FOND DU LAC        WI   CO-OP OBSERVER

            6.0 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       3 NE POYNETTE           43.42N 89.37W
12/20/2012  M9.0 INCH        COLUMBIA           WI   CO-OP OBSERVER

            9.0 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       4 NW PORTAGE            43.59N 89.52W
12/20/2012  M7.0 INCH        COLUMBIA           WI   CO-OP OBSERVER

            7.0 INCHES STORM TOTAL.

0700 AM     SNOW             MONROE                  42.60N 89.64W
12/20/2012  M2.8 INCH        GREEN              WI   CO-OP OBSERVER

            2.8 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       MARKESAN                43.71N 88.99W
12/20/2012  M7.1 INCH        GREEN LAKE         WI   CO-OP OBSERVER

            7.1 INCHES STORM TOTAL.

0700 AM     SNOW             2 NE JACKSON            43.34N 88.14W
12/20/2012  M5.0 INCH        WASHINGTON         WI   CO-OP OBSERVER

            5.0 INCHES STORM TOTAL.

0700 AM     SNOW             HUSTISFORD              43.35N 88.60W
12/20/2012  M4.0 INCH        DODGE              WI   CO-OP OBSERVER

            4.0 INCHES STORM TOTAL.

0700 AM     SNOW             2 SW FOND DU LAC        43.76N 88.48W
12/20/2012  M5.5 INCH        FOND DU LAC        WI   CO-OP OBSERVER

            5.5 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       1 SW ELKHART LAKE       43.82N 88.03W
12/20/2012  M6.0 INCH        SHEBOYGAN          WI   CO-OP OBSERVER

            6.0 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       DE FOREST               43.25N 89.35W
12/20/2012  M8.8 INCH        DANE               WI   CO-OP OBSERVER

            8.8 INCHES STORM TOTAL.

0700 AM     SNOW             2 NE DARLINGTON         42.70N 90.09W
12/20/2012  M4.5 INCH        LAFAYETTE          WI   CO-OP OBSERVER

            4.5 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       COTTAGE GROVE           43.08N 89.20W
12/20/2012  M8.1 INCH        DANE               WI   CO-OP OBSERVER

            8.1 INCHES STORM TOTAL.

0700 AM     SNOW             BRODHEAD                42.62N 89.38W
12/20/2012  M2.2 INCH        GREEN              WI   CO-OP OBSERVER

            2.2 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       BLACK EARTH             43.14N 89.75W
12/20/2012  M7.2 INCH        DANE               WI   CO-OP OBSERVER

            7.2 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       1 NE BARABOO            43.48N 89.73W
12/20/2012  M9.0 INCH        SAUK               WI   CO-OP OBSERVER

            9.0 INCHES STORM TOTAL.

0700 AM     SNOW             3 NW OCONOMOWOC         43.14N 88.54W
12/20/2012  M4.7 INCH        JEFFERSON          WI   CO-OP OBSERVER

            4.7 INCHES STORM TOTAL.

0716 AM     HEAVY SNOW       BARABOO                 43.47N 89.74W
12/20/2012  M7.8 INCH        SAUK               WI   CO-OP OBSERVER

            7.8 INCHES STORM TOTAL.

0730 AM     HEAVY SNOW       1 S MOUNT HOREB         42.99N 89.73W
12/20/2012  M7.8 INCH        DANE               WI   CO-OP OBSERVER

            7.8 INCHES STORM TOTAL.

0730 AM     HEAVY SNOW       4 N LA VALLE            43.64N 90.13W
12/20/2012  M7.8 INCH        SAUK               WI   CO-OP OBSERVER

            7.8 INCHES STORM TOTAL.

0730 AM     SNOW             DARLINGTON              42.68N 90.12W
12/20/2012  M4.3 INCH        LAFAYETTE          WI   CO-OP OBSERVER

            4.3 INCHES STORM TOTAL.

0800 AM     SNOW             ARLINGTON               43.34N 89.38W
12/20/2012  M5.0 INCH        COLUMBIA           WI   CO-OP OBSERVER

            5.0 INCHES STORM TOTAL.

0850 AM     HEAVY SNOW       MIDDLETON               43.10N 89.51W
12/20/2012  M9.0 INCH        DANE               WI   TRAINED SPOTTER

            9 INCHES STORM TOTAL. 7 INCHES THROUGH 7 AM. 2 INCHES 7-9
            AM. CONVECTIVE SNOW WITH LIGHTNING AND THUNDER AT 820-850
            AM.

0912 AM     HEAVY SNOW       5 SW MADISON            43.03N 89.45W
12/20/2012  M10.7 INCH       DANE               WI   CO-OP OBSERVER

            10.7 INCHES STORM TOTAL.

&&

ET

Local storm report, Dec 20, 9:46 AM CST, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
946 AM CST THU DEC 20 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 AM     HEAVY SLEET      RICHFIELD               43.26N 88.19W
12/20/2012  M6.00 INCH       WASHINGTON         WI   CO-OP OBSERVER

            6.0 INCHES STORM TOTAL.

0630 AM     SNOW             4 SW SOUTH WAYNE        42.53N 89.94W
12/20/2012  M4.0 INCH        LAFAYETTE          WI   CO-OP OBSERVER

            4.0 INCHES STORM TOTAL.

0638 AM     SNOW             WATERTOWN               43.19N 88.72W
12/20/2012  M4.5 INCH        JEFFERSON          WI   CO-OP OBSERVER

            4.5 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       1 SW WEST BEND          43.41N 88.20W
12/20/2012  M7.9 INCH        WASHINGTON         WI   CO-OP OBSERVER

            7.9 INCHES STORM TOTAL.

0700 AM     SNOW             3 NW WAYNE              43.54N 88.36W
12/20/2012  M5.0 INCH        WASHINGTON         WI   CO-OP OBSERVER

            5.0 INCHES STORM TOTAL.

0700 AM     HEAVY SNOW       WEST BEND               43.42N 88.18W
12/20/2012  M7.2 INCH        WASHINGTON         WI   CO-OP OBSERVER

            7.2 INCHES STORM TOTAL.

0755 AM     HEAVY SNOW       1 NNE REEDSBURG         43.55N 89.99W
12/20/2012  M7.0 INCH        SAUK               WI   CO-OP OBSERVER

            7.0 INCHES STORM TOTAL.

0800 AM     SNOW             1 NW SLINGER            43.34N 88.30W
12/20/2012  M5.0 INCH        WASHINGTON         WI   CO-OP OBSERVER

            5.0 INCHES STORM TOTAL.

0800 AM     HEAVY SNOW       2 W MADISON             43.08N 89.42W
12/20/2012  E7.0 INCH        DANE               WI   TRAINED SPOTTER

&&

ET

Local storm report, Dec 20, 9:47 AM CST, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
947 AM CST THU DEC 20 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     HEAVY SNOW       2 W MADISON             43.08N 89.42W
12/20/2012  E7.0 INCH        DANE               WI   TRAINED SPOTTER

&&

MRC

Local storm report, Dec 20, 9:49 AM CST, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
949 AM CST THU DEC 20 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0941 AM     HEAVY SNOW       1 NE MCFARLAND          43.03N 89.28W
12/20/2012  E7.0 INCH        DANE               WI   PUBLIC

            7.0 INCHES STORM TOTAL.

&&

ET

Local storm report, Dec 20, 9:52 AM CST, 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
952 AM CST THU DEC 20 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0929 AM     HEAVY SNOW       OREGON                  42.93N 89.38W
12/20/2012  M7.0 INCH        DANE               WI   TRAINED SPOTTER

            7.0 INCHES STORM TOTAL.

&&

ET

Local storm report, Dec 20, 9:57 AM CST, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
957 AM CST THU DEC 20 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0945 AM     SNOW             5 ENE HARTFORD          43.35N 88.30W
12/20/2012  M5.5 INCH        WASHINGTON         WI   TRAINED SPOTTER

            5.5 INCHES STORM TOTAL.

&&

ET

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

11 blizzard. Local standard time, as filed.

Blizzard, Marquette

When: December 20, 10:00 AM CST to December 21, 12:00 AM CST
Where: Marquette forecast zone
Reported by: Emergency Manager
Coordinates: 43.820, -89.399 (the zone’s center; the record gives no point)

Blizzard, Sauk

When: December 20, 10:00 AM CST to December 21, 12:00 AM CST
Where: Sauk forecast zone
Reported by: AWOS
Coordinates: 43.427, -89.948 (the zone’s center; the record gives no point)

Blizzard, Iowa

When: December 20, 10:00 AM CST to December 21, 12:00 AM CST
Where: Iowa forecast zone
Reported by: AWOS
Coordinates: 43.001, -90.135 (the zone’s center; the record gives no point)

Blizzard, Lafayette

When: December 20, 10:00 AM CST to December 21, 12:00 AM CST
Where: Lafayette forecast zone
Reported by: Law Enforcement
Coordinates: 42.661, -90.132 (the zone’s center; the record gives no point)

Blizzard, Columbia

When: December 20, 11:00 AM CST to December 21, 12:00 AM CST
Where: Columbia forecast zone
Reported by: Law Enforcement
Coordinates: 43.467, -89.334 (the zone’s center; the record gives no point)

A couple of Columbia County sheriff deputies, trying to aid stranded motorists, became stuck themselves in the drifting snow. Plow crews had difficulty reaching the deputies, as well as the stranded motorists they were trying to help.

Blizzard, Dane

When: December 20, 11:00 AM CST to December 21, 12:00 AM CST
Where: Dane forecast zone
Reported by: Official NWS Observations
Coordinates: 43.067, -89.418 (the zone’s center; the record gives no point)

Blizzard, Green

When: December 20, 11:00 AM CST to December 21, 12:00 AM CST
Where: Green forecast zone
Reported by: AWOS
Coordinates: 42.680, -89.602 (the zone’s center; the record gives no point)

Blizzard, Rock

When: December 20, 1:00 PM CST to December 21, 12:39 AM CST
Where: Rock forecast zone
Reported by: AWOS
Coordinates: 42.671, -89.072 (the zone’s center; the record gives no point)

Blizzard, Green Lake

When: December 20, 3:00 PM CST to December 21, 12:00 AM CST
Where: Green Lake forecast zone
Reported by: Emergency Manager
Coordinates: 43.800, -89.045 (the zone’s center; the record gives no point)

Blizzard, Dodge

When: December 20, 3:00 PM CST to December 21, 12:39 AM CST
Where: Dodge forecast zone
Reported by: AWOS
Coordinates: 43.416, -88.707 (the zone’s center; the record gives no point)

Blizzard, Fond du Lac

When: December 20, 4:00 PM CST to December 21, 12:39 AM CST
Where: Fond du Lac forecast zone
Reported by: ASOS
Coordinates: 43.754, -88.488 (the zone’s center; the record gives no point)

A portion of Highway 41 was closed due to severe blowing and drifting snow.

What these are

Blizzard: Sustained winds or frequent gusts of 35 mph or more with falling or blowing snow that cuts visibility below a quarter mile for three hours or longer.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Wisconsin in 2012 Every state in 2012 This day in weather history Warnings in Wisconsin, December 2012

Sources

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: 427121, 427124, 427125, 427126, 427127, 427128, 427129, 427131, 427122, 427132, 427123.