Tornadoes and Hail in Wisconsin, June 6, 1999

A significant change in the upper level pattern to a more southwesterly flow allowed tropical-like moisture to return to southern Wisconsin in conjunction with an upper level shortwave trough. The result was the first severe weather outbreak across southern Wisconsin since May 16, 1999. A series of upper level shorwaves contintued to move through the Great Lakes region during the remainder of the week into the weekend of of June 12-13, 1999. These shortwaves resulted in additional rounds of severe weather across southcentral and southeast Wisconsin. On June 6th, scattered severe storms eventually became orientated in short lines that produced 2 tornadoes, 10 gustnadoes (classified as thunderstorm wind damage), 3 funnel clouds, hail up to the size of golfballs, damaging straight-line downburst winds up to 80 mph, and isolated torrential rainfalls of around 1 inch within 20 to 30 minutes. In Evansville (Rock Co.), 1/2 inch rain fell within 10 minutes along with large hail. In addition, two people were injured by lightning strikes. Otherwise, numerous large trees and power lines were toppled by the powerful thunderstorm winds.A weak (F0) tornado briefly touched down on the northwest side of Lake Mills (the body of water), Jefferson County, uprooting and snapping large trees, but not causing any other damage. Another weak (F1) tornado spun up just southwest of the intersection of Oakdale and Skyline roads northwest of Big Bend (Waukesha Co.), damaging 6 homes (one had major damage), and 2 pole sheds. This Waukesha tornado was on the ground for about 2/10 of a mile, and weakened after it crossed Oakdale Rd. Most interestingly, the number of gustnadoes reported and verified was the greatest in recent memory. A couple of them were captured on video tape. Several of them resulted in tree damage, and all ten were classified as thunderstorm wind damage. Locations of gustnadoes were: 1) Rock county...Orfordville; Walworth County...3NW Darien, 1W Delevan, Millard, and 1NW East Troy; Waukesha County...3.5W Muckwonago, 1WNW North Prairie, and 2 of them 2SW Harland; Washington County...3SW West Bend on Little Cedar Lake. The Little Cedar Lake gustnado actually spun up on the water surface (gustspout?!?!) and then moved onshore, damaging a pier and uprooting a couple trees before disspating. It was observed by a trained spotter. Another trained spotter found themselve briefly inside one of the gustnadoes southwest of Hartland! The fact that so many gustnadoes were plainly visibile can be partially attributed to significant amounts of dust and dirt that were picked up off nearby farm fields. The was made possible by dry weather during the preceeding 3 weeks coupled with late planting (little vegetation) of some fields. Other notable damage reports included: a motorhome was blown onto State Highway 14 near Evansville (Rock Co.), injuring two people; a home in Hebron (Jefferson Co.) was damaged by a wind-toppled tree, while northeast of Hebron a barn was damaged by fallen trees; a pontoon boat was blown 500 feet near Elkhorn (Walworth Co.); a construction trailer west/northwest of North Prairie (Waukesha Co.) was rolled over and damaged by a gustnado; in Brookfield (Waukesha Co.) a construction trailer was damaged after strong thunderstorm winds flipped it over, while elsewhere in Brookfield a toppled tree damaged a home; in Germantown (Washington Co.)... a home had it gutters and shingles damaged while one of its windows was blown in; just west of Claladenio (Racine Co.) a truck was flipped over by strong thunderstorm winds, and a four block area on Milwaukee's west side suffered an intense wet microburst that damaged 14 homes, 17 vehicles, uprooted 100 trees, and knocked over a few power lines.