On October 20th, low pressure developed over eastern Colorado. A warm front extended from the low, across southern Minnesota into central Wisconsin. Temperatures north of the warm front remained in the 30s, while readings to the south warmed into the 40s and 50s. During the early morning hours of the 21st, the low moved from Colorado into southern Minnesota while the warm front remained nearly stationary. As the low approached the area, snow developed north of the warm front from east-central Minnesota into northern and central Wisconsin. During the day of the 21st, the low moved east along the warm front into east-central Wisconsin. This served to keep the cold air in place and for the snow to continue across northern and central Wisconsin. Portions of central Wisconsin received over 6 inches of snow with Wausau receiving around 8 inches.
Snow totals for October 21st.
ZCZC MKEPNSLSE ABUS34 KLSE 212123 PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 422 PM CDT MON OCT 21 2002 SNOW EVENT TOTALS ACROSS THE AREA THROUGH 4 PM LOCATION COUNTY SNOWFALL(IN) ...WISCONSIN... PERKINSTOWN 5E TAYLOR 7.0 LUBLIN TAYLOR 4.5 RIB LAKE TAYLOR 5 TO 6 GAD TAYLOR 6.0 WITHEE CLARK 7.0 LONGWOOD CLARK 5.0 NEILLSVILLE CLARK 3.0 BIG FLATS ADAMS 4.0 NEW ROME ADAMS 1 TO 2 FRIENDSHIP 10 NE ADAMS 0.5 BLACK RIVER FALLS 2 SE JACKSON 2.5 MAUSTON JUNEAU 0.5 OSSEO TREMPEALEAU 1.0 $$ NNNN