Updated 7/17/09 at 7:10 am
We've had a relatively quiet severe season across Wisconsin in 2009 through June 30th, as compared to previous years. However, there have been relatively quiet years in the past. It seems the jet stream and storm pattern so far in 2009 has resulted in most of the severe weather activity to favor the Dakotas, Minnesota, southeast Wyoming, Nebraska, Iowa, and Illinois area.
Luckily, we documented the number of Severe Thunderstorm Watches and Tornado Watches issued for at least a small part of Wisconsin over the past few years. Below is a table showing the results. So, activity in 2009 is below normal, but there were other quiet "first-half-of-the-year" time periods. The average number of Severe Thunderstorm Watches issued for at least a part of Wisconsin during the 1st half of the year was 14 for the period of 1998 through 2009. The average number of Tornado Watches was 7. Bar graph generated by Chad Woodward, an amateur radio operator and spotter associated with the MidWest Storm Tracking and Response Center based in Monona, WI.
Arriving at the number of convective warnings issued in Wisconsin from 1998 through 2009, we have an idea of how many warnings have been issued by WFO Milwaukee/Sullivan (MKX), that services 20 counties in south-central and southeast Wisconsin. In 2008 and 2009, we've issued "Storm-based" warnings rather than "county-based" warnings. There may be parts of one, two, three, four, or even five counties in a "storm-based warning." To keep things simple, we converted the storm-based warnings in 2009 and 2008 to their county-based equivalent, so that we don't mix apples and oranges (the 39 storm-based warnings in 2009 equaled 80 county-based warnings). The number for 2008 is 141 storm-based warnings which equals 330 county-based warnings. The average number of warnings during the first half of the year during the period from 1998 to 2009 is 134. Bar graph generated by Chad Woodward, an amateur radio operator and spotter associated with the MidWest Storm Tracking and Response Center based in Monona,