Heavy, Wet Snow Of April 19, 2011
Snowfall Maps | Snowfall Reports |
A potent storm system tracked northeast from the Southern Plains to across northern Illinois by the evening of Tuesday, April 19th. Areas of precipitation developed north and northwest of this system, moving into southeast Minnesota and northeast Iowa before daybreak on April 19th, spreading across western Wisconsin as the morning wore on. With unseasonably cold air in place, the bulk of the precipitation fell as heavy, wet snow. However, temperatures in northeast Iowa and southwest Wisconsin were a bit warmer, which resulted in a mix of rain, snow, and sleet. A few rumbles of thunder even occurred over southwest Wisconsin.
Due to warm ground, there was considerable melting at first, with accumulations mainly on grassy surfaces. A slushy accumulation gradually occurred on roadways as inch per hour snowfall rates developed.
In addition to the all the melting, the high water content of the snow kept accumulations lower then what they could have been. Snow to water ratios were as low as 5:1 (for every inch of water, there would be 5 inches of snow). However, higher elevations such as bluff and ridge tops (where temperatures were a bit cooler), ratios were 12 to 15 to 1. For instance, the National Weather Service - La Crosse office is located on a bluff that overlooks the city of La Crosse, where 8.3 inches of snow fell. The La Crosse Airport, about 600 ft lower in elevation than the NWS office, only recorded 3.1 inches of snow. Water equivalent precipitation for both locations was right around 6 tenths of an inch.
April 19-20, 2011 Snowfall Analysis
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Snowfall Totals
PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 935 AM CDT WED APR 20 2011 ...24 HOUR SNOWFALL TOTALS ACROSS THE AREA... LOCATION SNOWFALL TIME LAT/LON IOWA ...ALLAMAKEE COUNTY... LANSING 4SE 3.2 0700 AM 43.32N 91.16W ...CHICKASAW COUNTY... NEW HAMPTON 3.5 0700 AM 43.06N 92.31W ...CLAYTON COUNTY... ELKADER 6SSW 1.8 0700 AM 42.79N 91.45W VOLGA 1.0 0700 AM 42.81N 91.52W ...FAYETTE COUNTY... FAYETTE 2.7 0700 AM 42.85N 91.82W ...FLOYD COUNTY... CHARLES CITY COOP 3.0 0700 AM 43.08N 92.67W NASHUA 3.0 0700 AM 42.94N 92.57W ...HOWARD COUNTY... CRESCO 5.5 0700 AM 43.37N 92.11W ...MITCHELL COUNTY... OSAGE 4.2 0700 AM 43.28N 92.81W ST ANSGAR 4.0 0700 AM 43.37N 92.83W ...WINNESHIEK COUNTY... WAUCOMA 2.0 0700 AM 43.05N 92.04W MINNESOTA ...DODGE COUNTY... DODGE CENTER 1.2 0700 AM 44.04N 92.88W ...FILLMORE COUNTY... PRESTON 3.8 0700 AM 43.67N 92.07W SPRING VALLEY 3E 3.2 0700 AM 43.68N 92.33W SPRING VALLEY 2.0 0700 AM 43.69N 92.39W ...HOUSTON COUNTY... CALEDONIA 6S 6.7 0700 AM 43.55N 91.51W SPRING GROVE 4N 5.8 0700 AM 43.61N 91.62W LA CRESCENT 1NNW 5.1 0700 AM 43.83N 91.31W CALEDONIA 5.0 0700 AM 43.63N 91.50W ...MOWER COUNTY... GRAND MEADOW 4.2 0700 AM 43.71N 92.56W AUSTIN 1.0 0700 AM 43.67N 92.95W ...OLMSTED COUNTY... ELGIN 1.2 0700 AM 44.10N 92.27W ...WABASHA COUNTY... THEILMAN 0.3 0700 AM 44.28N 92.19W ...WINONA COUNTY... LA CRESCENT DAM 7 3.0 0700 AM 43.87N 91.31W WINONA 3.0 0700 AM 44.09N 91.67W ALTURA 5W 1.0 0700 AM 44.06N 92.04W WISCONSIN ...ADAMS COUNTY... MONROE CENTER 5.0 0700 AM 44.11N 89.92W FRIENDSHIP 3.8 0700 AM 43.98N 89.83W ...CLARK COUNTY... NEILLSVILLE 3SW 2.0 0700 AM 44.53N 90.64W NEILLSVILLE 4 NNE 2.0 0700 AM 44.61N 90.56W ...CRAWFORD COUNTY... SOLDIERS GROVE 3.0 0700 AM 43.39N 90.78W GAYS MILLS 1.0 0700 AM 43.32N 90.85W ...GRANT COUNTY... LANCASTER 4WSW 2.0 0700 AM 42.83N 90.79W SINSINAWA 0.2 0700 AM 42.52N 90.54W CUBA CITY 0.1 0700 AM 42.63N 90.46W ...JACKSON COUNTY... BLACK RIVER FALLS STP 3.4 0700 AM 44.29N 90.85W TAYLOR 1.0 0700 AM 44.32N 91.12W ...LA CROSSE COUNTY... LA CROSSE WEATHER 8.3 0700 AM 43.82N 91.19W HOLMEN 2S 3.8 0700 AM 43.93N 91.25W LA CROSSE ASOS 3.1 0700 AM 43.88N 91.26W LA CROSSE 4NNW 2.8 0700 AM 43.87N 91.27W ...MONROE COUNTY... WARRENS 9.0 0700 AM 44.10N 90.59W TUNNEL CITY 6.6 0700 AM 44.01N 90.57W SPARTA 6.0 0700 AM 43.94N 90.82W ...RICHLAND COUNTY... RICHLAND CENTER 1NW 3.0 0700 AM 43.36N 90.42W GILLINGHAM 2.5 0838 AM 43.43N 90.45W ...TAYLOR COUNTY... WESTBORO 4E 1.8 0700 AM 45.35N 90.22W MEDFORD 1.2 0700 AM 45.13N 90.34W ...TREMPEALEAU COUNTY... GALESVILLE 2ESE 5.0 0700 AM 44.08N 91.34W TREMPEALEAU DAM 6 4.0 0700 AM 44.00N 91.44W BLAIR 2NW 2.0 0700 AM 44.31N 91.27W ...VERNON COUNTY... WESTBY 3ENE 5.1 0700 AM 43.68N 90.81W LA FARGE 4.5 0700 AM 43.57N 90.64W GENOA 4.0 0700 AM 43.57N 91.23W VIROQUA 3.0 0700 AM 43.55N 90.90W ONTARIO 3E 2.8 0700 AM 43.72N 90.60W 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