A multi-faceted winter storm brought a variety of weather to the Upper Midwest. Three areas of low pressure crossed the region bringing snow, strong winds, blowing and drifting snow, arctic air and dangerously cold wind chills to the area. The first area of low pressure moved slowly across northern Minnesota during the day of the 20th, reaching northwest Wisconsin during the evening. The second area of low pressure developed over southwest Minnesota during the morning of the 20th, reaching the southern tip of Lake Michigan during the evening. The third area of low pressure tracked quickly from northern Oklahoma into Ohio and Pennslyvania during the day and evening. Connecting all three areas of low pressure was a strong cold front.

Snow developed during the day ahead of the areas of low pressure and cold front. The accumulating snow continued into the evening before tapering off to very light snow and flurries. Snowfall amounts across much of the region averaged 2 to 5 inches with some locally higher amounts. The highest reported amounts were 7.6 inches at Preston, Minnesota and 7.5 inches just south of Galesville, Wisconsin. See the map below for a graphical depiction of the snowfall. For this event, La Crosse received 5.2 inches of snow, pushing the December 2008 monthly total to 25.2 inches. That ranks December 2008 as the 5th snowiest on record as of the 20th. For Rochester, 7.0 inches of snow fell, raising the December 2008 monthly total to 24.9 inches, which ranks as the 3rd snowiest on record as of the 20th. The most snow ever measured in December in La Crosse was 30.4 inches in 1990. The most December snow ever measured in Rochester was 35.3 inches in 2000.

 

Click to Enlarge Loop
National Surface Map and Radar Loop From 6 AM Dec 20 to Midnight Dec 21	Temperature (green contours, colored background) and Wind Chill (yellow plotted values) Loop From 2 PM Sat Dec 20 to 6 AM Sun Dec 21

In addition to the snow, once the strong cold front moved through, arctic air plunged into the region with temperatures plummeting between 20 and 30 degrees in just a few hours. Along with the falling temperatures, northwest winds of 15 to 30 mph were common behind the front. The combination of the plummeting temperatures and strong winds created wind chills of 20 to 40 below zero. The strong winds also whipped up the freshly fallen snow to create blowing and drifting snow through much of the night with the largest impacts on travel over northeast Iowa and southeast Minnesota. 2 to 4 foot drifts were common.

Overall, forecasts leading up to the storm provided good guidance to the public for the snow, wind, very cold wind chill, and blowing and drifting snow hazards. A Winter Storm Watch was issued around 12pm Friday for the storm with Winter Storm Warnings issued around 3 am Saturday morning for the entire area. This provided 12-18 hours of advance notice for the incoming weather hazards.

 

Snowfall Totals for December 20, 2008 (click to enlarge)

  

 

Forecast Graphic Issued 133 PM Friday December 19, 2008 (click to enlarge)

Detailed Listing of Snowfall Totals

PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1040 AM CST SUN DEC 21 2008 ...RECENT REPORTED SNOWFALL TOTALS... LOCATION SNOWFALL TIME LAT/LON NORTHEAST IOWA ...ALLAMAKEE COUNTY... DORCHESTER 4.1 0700 AM 43.47N 91.51W WAUKON 8NW 4.0 0729 AM 43.34N 91.6W ...CHICKASAW COUNTY... IONIA 2W 1.5 0700 AM 43.03N 92.50W ...CLAYTON COUNTY... ELKADER 6SSW 2.1 0700 AM 42.79N 91.45W ...FAYETTE COUNTY... CLERMONT 5.9 0700 AM 43.00N 91.66W OELWEIN 1WNW 2.1 0650 AM 42.68N 91.93W FAYETTE 1.6 0700 AM 42.85N 91.82W ...FLOYD COUNTY... CHARLES CITY COOP 2.6 0700 AM 43.08N 92.67W ...HOWARD COUNTY... CRESCO 6.5 0700 AM 43.37N 92.11W ELMA 2.7 0700 AM 43.24N 92.44W ...WINNESHIEK COUNTY... DECORAH 8ENE 3.5 0858 AM 43.33N 91.7W SOUTHEAST MINNESOTA ...DODGE COUNTY... DODGE CENTER 5.5 0700 AM 44.04N 92.88W ...FILLMORE COUNTY... PRESTON 7.6 0700 AM 43.67N 92.07W LANESBORO 5.3 0700 AM 43.72N 91.97W PETERSON 1S 4.0 0639 AM 43.78N 91.82W ...HOUSTON COUNTY... CALEDONIA 6S 5.0 0700 AM 43.55N 91.51W CALEDONIA 4.6 0700 AM 43.63N 91.50W ...MOWER COUNTY... GRAND MEADOW 6.3 0700 AM 43.71N 92.56W ...OLMSTED COUNTY... ROCHESTER AP 2NE 7.0 0700 AM 43.93N 92.48W ELGIN 2SSW 4.9 0700 AM 44.10N 92.27W ...WABASHA COUNTY... THEILMAN 1SSW 5.9 0700 AM 44.28N 92.19W ZUMBRO FALLS 5.1 0700 AM 44.29N 92.42W WABASHA 3.0 0700 AM 44.39N 92.05W ...WINONA COUNTY... WINONA 4S 4.5 0833 AM 44.01N 91.66W WINONA DAM 5A 3.0 0700 AM 44.09N 91.67W SOUTHWEST AND CENTRAL WISCONSIN ...ADAMS COUNTY... FRIENDSHIP 10NE 4.5 0420 AM 44.04N 89.63W MONROE CENTER 3.5 0700 AM 44.11N 89.92W ...BUFFALO COUNTY... MONDOVI 6S 4.5 0700 AM 44.48N 91.67W ...CLARK COUNTY... NEILLSVILLE 3SW 4.0 0700 AM 44.53N 90.64W OWEN 2N 3.8 0700 AM 44.98N 90.55W LONGWOOD 3.5 0810 AM 44.89N 90.6W COLBY 4SW 3.0 0919 AM 44.87N 90.42W ...GRANT COUNTY... LANCASTER 2.3 0841 AM 42.84N 90.71W ...JACKSON COUNTY... BLACK RIVER FALLS STP 5.0 0700 AM 44.29N 90.85W TAYLOR 4.0 0700 AM 44.32N 91.12W MATHER 3NW 4.0 0700 AM 44.17N 90.35W HATFIELD 4.0 0700 AM 44.42N 90.73W ...JUNEAU COUNTY... MAUSTON 4.0 0658 AM 43.80N 90.08W NECEDAH 2SE 3.9 0700 AM 44.00N 90.04W ...LA CROSSE COUNTY... LA CROSSE 5SE 6.5 0700 AM 43.77N 91.15W LA CROSSE WFO 5.2 0700 AM 43.82N 91.19W LA CROSSE 4NNW 5.0 0700 AM 43.87N 91.27W HOLMEN 2S 4.7 0700 AM 43.93N 91.25W ...MONROE COUNTY... WARRENS 5WSW 6.5 0700 AM 44.10N 90.59W FOUR CORNERS 5.0 0700 AM 44.07N 90.92W TUNNEL CITY 1S 4.3 0700 AM 44.01N 90.57W ...RICHLAND COUNTY... RICHLAND CENTER 3.2 0700 AM 43.32N 90.38W ...TAYLOR COUNTY... MEDFORD 4.0 0700 AM 45.13N 90.34W ...TREMPEALEAU COUNTY... GALESVILLE 1S 7.5 0700 AM 44.06N 91.36W BLAIR 4.0 0700 AM 44.29N 91.22W ...VERNON COUNTY... WESTBY 3ENE 4.3 0700 AM 43.68N 90.81W HILLSBORO 4.1 0700 AM 43.65N 90.33W LA FARGE 3.7 0700 AM 43.57N 90.64W OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING EQUIPMENT AND EXPOSURE. NOT ALL DATA LISTED IS CONSIDERED OFFICIAL. FOR THIS...AND A WEALTH OF OTHER RIVER AND WEATHER INFORMATION... VISIT OUR WEBSITE AT WEATHER.GOV/LACROSSE

Detailed Listing of the Coldest Wind Chills Reached
(12 pm Sat Dec 20 - 12 pm Sun Dec 21)

STATION COUNTY TIME WIND CHILL

GRAND MEADOW - KIMT       MOWER             715 AM    -47 F
CENTURY HIGH SCHOOL AWS   OLMSTED           344 AM    -43 F
MONONA HS AWS             CLAYTON           614 AM    -43 F
WEST UNION AWS            FAYETTE           814 AM    -41 F
WEST CONCORD - KIMT       DODGE             635 AM    -41 F
ROCHESTER ASOS            OLMSTED           554 AM    -40 F
PRESTON KIMT              FILLMORE          234 AM    -40 F
FENNIMORE ELEMENTARY AWS  GRANT             830 AM    -39 F
MOUNT STERLING 1S RWIS    CRAWFORD          508 AM    -39 F
NEW HAMPTON RWIS          CHICKASAW         502 AM    -39 F
CANTON RWIS               FILLMORE          344 AM    -39 F
DODGE CENTER AWOS         DODGE            1235 AM    -39 F
KELLOGG RWIS              WABASHA           224 AM    -39 F
ROCHESTER KELLOGG - KIMT  OLMSTED           635 AM    -39 F
DECORAH 2SE RWIS          WINNESHIEK        205 AM    -38 F
AUSTIN AWOS               MOWER             155 AM    -38 F
ARCADIA HILL RWIS         TREMPEALEAU       509 AM    -38 F
CRESCO KIMT               HOWARD            755 AM    -38 F
NEW HAMPTON AWS           CHICKASAW         729 AM    -38 F
WILLOW CREEK - KIMT       OLMSTED           814 AM    -38 F
NWS LA CROSSE             LA CROSSE         634 AM    -37 F
FRIENDSHIP AWS            ADAMS             714 AM    -37 F
JOHN ADAMS - KIMT         OLMSTED           535 AM    -37 F
WSU CAMPUS AWS            WINONA            529 AM    -37 F
VOLK FIELD                JUNEAU            733 AM    -37 F
RICHLAND CENTER AWS       RICHLAND          814 AM    -37 F
PRESTON AWOS              FILLMORE          559 AM    -37 F
DIAMOND LAKE RAWS         TAYLOR            714 AM    -36 F
LOYAL SCHOOL AWS          CLARK             859 AM    -36 F
STANLEY 1 SE RWIS         CHIPPEWA          823 AM    -36 F
OELWEIN AWOS              FAYETTE           455 AM    -35 F
SOUTH WINNESHIEK SCHOOL   WINNESHIEK        729 AM    -35 F
CHARLES CITY AWOS         FLOYD             115 AM    -35 F
ALMA AWS                  BUFFALO           744 AM    -35 F
MEDFORD AWOS              TAYLOR            715 AM    -35 F
PLAINFIELD AWS            CHICKASAW         659 AM    -34 F
OSAGE - KIMT              MITCHELL         1255 AM    -34 F
PRAIRIE DU CHIEN AWOS     CRAWFORD          755 AM    -34 F
WISC DELLS AWOS           SAUK              915 AM    -34 F
LA CROSSE ASOS            LA CROSSE         353 AM    -34 F
BUFFALO LUTHERAN AWS      BUFFALO           359 AM    -34 F
NECEDAH RAWS              JUNEAU            948 AM    -34 F
BLACK RIVER FALLS RWIS    JACKSON           808 AM    -33 F
I-90 AT I-94 RWIS         JUNEAU            805 AM    -33 F
TOMAH 4N RWIS             MONROE            706 AM    -33 F
5W TOMAH RWIS             MONROE            708 AM    -32 F
CRESTWOOD AWS             HOWARD            427 AM    -32 F
MAUSTON APRS              JUNEAU            748 AM    -31 F
DECORAH AWOS              WINNESHIEK        615 AM    -31 F
WINONA AWOS               WINONA            354 AM    -31 F
EASTERN ALLAMAKEE SCHOOL  ALLAMAKEE         114 AM    -30 F
PLAINVIEW AWS             WABASHA           529 AM    -30 F
SPARTA AWOS               MONROE            455 AM    -30 F
DICKEYVILLE RWIS          GRANT             902 AM    -30 F
ALBERT LEA - KIMT         FREEBORN          415 AM    -29 F
BLACK RIVER FALLS RAWS    JACKSON           415 AM    -29 F
CALEDONIA RWIS            HOUSTON           516 AM    -29 F
MCGREGOR MS AWS           CLAYTON           544 AM    -28 F
LA CROSSE 1S APRS         LA CROSSE         726 AM    -28 F
BOSCOBEL ASOS             GRANT             848 AM    -27 F
PRAIRIE DU CHIEN RWIS     CRAWFORD          207 AM    -27 F
RICEVILLE - KIMT          HOWARD            916 AM    -26 F
3N LA CRESCENT APRS       HOUSTON           749 AM    -25 F

KEY TO OBSERVATION TYPES

AWS - SENSORS FROM AWS INCORPORATED. OFTEN LOCATED AT SCHOOLS.
RWIS - ROAD WEATHER INFORMATION SYSTEMS. LOCATED ON MAJOR ROADS AND BRIDGES.
RAWS - FIRE WEATHER OBSERVATIONS. OFTEN LOCATED IN FORESTS.
ASOS/AWOS - AVIATION WEATHER OBSERVATIONS. LOCATED AT AIRPORTS.


OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING EQUIPMENT
AND EXPOSURE. NOT ALL DATA LISTED IS CONSIDERED OFFICIAL.