Updated 200 am CDT Tue Sep 23, 2009
...Record Daily Maximum Precipitation set at Madison WI...
Total rainfall at the Dane County Regional Airport in Madison on Tuesday, September 22, 2009 was 3.67". This set a new record daily rainfall for the date. The previous record was 1.37" in 1988.
In addition, this amount sets the record for any daily rainfall in the month of September. The previous record daily rainfall for September was 3.40" set on September 18th, 1874.
This is also one of the greatest 1 day rainfall totals for any day of any month in Madison. It ties for 8th all time greatest rainfall. Here is the list of heaviest calendar day rainfalls at Madison since 1850:
Rank Value Date
1 4.96 8/ 8/1906
2 4.51 6/17/1996
3 4.32 7/21/1881
4 4.11 6/ 8/2008
5 3.89 7/ 3/1975
6 3.82 7/11/1878
7 3.75 7/ 5/1993
8 3.67 9/22/2009
8 3.67 6/ 5/1963
9 3.66 5/21/2004
10 3.65 7/19/1950
11 3.64 5/23/1966
Seveal periods of moderate to heavy rain at the Madison airport resulted in some urban flooding when water collected in low spots. The area around the Madison airport sits in a large, relatively flat, bowl-shaped depression. Therefore, drainage of heavy rains from this area isn't the best. Below are a couple pictures of the flooded parking lot on the Madison Area Technical College (MATC) campus, which sits inside the bowl-shaped depression. The pictures were forwarded to Wisconsin Emerency Management in Madsion who then forwarded them to WFO Milwaukee. Click on the images for larger versions.
Below is a simple graphic showing highly-smoothed rainall contours for the September 22nd rain event through about 530 pm, based on WSR-88D Doppler radar esitimates. Your local rainfall amounts may differ from this basic image. Click on the image for a larger version.
James Wood, Climate Program Leader
Jeff Craven, Science and Operations Officer
Rusty Kapela, WCM
NWS Milwaukee/Sullivan WI