Issued 335 pm CST Tue Feb 26 2013 (Updated 520 pm)
Doppler radar provides many great things, including estimates of snow accumulation. Given the windy conditions, it is sometimes difficult to estimate snow amounts looking at airport weather observations, because the snow blows horizontally and does not "catch" easily in the automated rain gauges. So, in cases like this, snow amounts can be estimated more accurately by radar.
Below are five images. The first is the snow total so far in southeast Wisconsin Tuesday afternoon through 5 pm CST. 3-5" has been common in Kenosha County, with 2-4" in Racine County and southern Walworth County. Over Milwaukee County, 1-2" north and 2-3" south has fallen. 1-2" has accumulated over much of Rock County, northern Walworth County, and southeast parts of Jefferson and Waukesha Counties.
The 2nd image below shows the hourly snowfall accumulation from 1-2 pm CST. At least an inch of snow fell during that hour from the city of Racine to Lake Geneva on south to the IL border, with around 1.5 inches for the south half of Kenosha County.
The 3rd image below shows the hourly snowfall accumulation from 2-3 pm CST. Snowfall of 0.5" or more fell during that hour as far north as the Janesville, Mukwonago, and Milwaukee areas. Amounts around 1" per hour were seen over much of Racine, Kenosha, and southern Walworth Counties.
The 4th image below is the hourly snow estimate from 3-4 pm CST. Snowfall of 0.5 to 0.8" in the past hour has been common south of a line from Mequon to Waukesha, Fort Atkinson, and Edgerton. Up to 1 additional inch fell from Lake Geneva to Racine and Kenosha.
The 5th image below is one hour snowfall from 4-5 pm CST. 0.5 to 0.8" amounts in one hour were common south of a line from Fitchburg and Jefferson, to West Bend and Sheboygan. Heaviest amounts around 1" covered much of Racine County into southern Milwaukee County.
Jeff Craven, Science and Operations Officer
National Weather Service Milwaukee/Sullivan, WI