Summary of the February 21, 2009 Winter Storm (Updated 2/22)

A strong upper level disturbance originating in Alberta, Canada tracked southeast into the Upper Mississippi River Valley overnight on February 20th. Meanwhile, a surface low pressure system developed over Missouri which tracked northeast across far southeast Wisconsin (between Milwaukee and Racine) on the afternoon of the 21st. 

Below is an animation of infrared imagery of the storm, with isobars and the track of the surface low superimposed.

Infrared imagery of the Feb 21st winter storm.

Below is a radar animation of the storm.

Radar animation of the storm.

Widespread snow associated with this complex system overspread southern Wisconsin after midnight on the evening of the 20th and continued through the early evening of the 21st. Widespread snowfall amounts of 5 to 8 inches were observed, with the heaviest amounts over southeast Wisconsin. 

Snowfall map of southern Wisconsin.

Some of the higher totals of the event are listed below:

INCHES  LOCATION                 COUNTY          SOURCE     
------ ----------------------- -------------- -----------------
8.8 1 N WEST BEND WASHINGTON SPOTTER
8.7 1.8 SE WAUKESHA WAUKESHA COCORAHS
8.5 ALLENTON (WWTP) WASHINGTON COOP
8.5 1 NW BELGIUM (WWTP) OZAUKEE COOP
8.0 4 S SHEBOYGAN (WWTP) SHEBOYGAN COOP
8.0 WAUKESHA (WWTP) WAUKESHA COOP
8.0 2 ESE WAUKESHA WAUKESHA COOP/NWS EMPLOYEE
7.8 1 SW ELKHART LAKE SHEBOYGAN COOP
7.8 WEST ALLIS MILWAUKEE COOP
7.7 RICHFIELD WASHINGTON COOP
7.4 LAKE MILLS JEFFERSON COOP
7.4 5 SW MADISON DANE SPOTTER
7.3 WISC-TV3 MADISON DANE MEDIA
7.3 2 NW FRANKLIN MILWAUKEE SPOTTER
7.3 WATERTOWN (WWTP) JEFFERSON COOP
7.0 SHEBOYGAN (SOUTHWEST) SHEBOYGAN COOP
7.0 BLANCHARDVILLE LAFAYETTE COOP
7.0 2 E HOLY HILL WASHINGTON COOP
7.0 1.1 S WATERTOWN JEFFERSON COCORAHS

Steve Davis and Bill Borghoff


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