EF1 tornado in Walworth County, Wisconsin

A tornado moved into extreme south-central Walworth County from Illinois about 5,100 feet west of the intersection of Alden Road and State Line Road, and quickly intensified to EF-1 rating. It moved northeast for over 5 miles before dissipating about 1,700 feet southeast of the intersection of County Road BB and Zenda Road. Five homes sustained damage, with two homes severely damaged. The tornado crossed CTH B where it dog-legs east of Swamp Angel Rd. Collectively, three sheds and two barns were damaged, with one of the barns flattened. Eight wooden power poles were also snapped, along with numerous trees and fences. On one farm, 4 cows, and several chickens and turkeys were killed by tornado debris. WeEnergy Utility reported about 4000 homes without electrical power in the county due to downed power-lines. The average path length was 60 yards in width. The EF1 estimated wind speed of 105 mph was based on DI 2(FR12) DOD 4. The loss estimate was produced by Walworth County Emergency Management. The exact start location is Lat 42.49507 Lon -88.56948. The exact end location is Lat 42.53464 Lon -88.47970.

An out-of-season round of strong to severe, surface-based, thunderstorms developed in Southeast Wisconsin during the mid-afternoon of November 22nd, which resulted in two tornadoes. This severe weather was related to low pressure lifting northeast from southwestern to central Wisconsin which brought a warm front up into southern Wisconsin. Afternoon temperatures peaked in the lower to mid 60s In the counties of Walworth, Racine, and Kenosha, with dewpoints reaching the mid to upper 50s. Instability with the unseasonable warmth just south of the warm front, with surface based CAPE values between 500 J/kg to 1000 J/kg, allowed for the thunderstorm development. Strong lift associated with the right entrance region of a 50 to 60 knot mid-level jet, strong deep layer shear and steep mid level lapse rates allowed super-cell thunderstorms with rotating updrafts to fire up along and ahead of a cold front trailing south of the low. Strong low-level shear developed just south of the warm front which led to one tornado in Walworth County and the other from far northern Kenosha County into southern Racine County around Union Grove. About 3,000 customers lost electric power due to the tornadoes and accompanying thunderstorms.