An intensifying 50 to 70 knot low-level jet ahead of an intense negatively-tilted upper level trough over the Plains transported low-level moisture and instability into southern Wisconsin during the early morning hours of October 26th. Overall forcing for ascent increased as a vorticity maximum rounded the base of the upper trough and lifted northeast across western Wisconsin.  Severe thunderstorms developed ahead of a surface cold/occluded front that trailed from record surface low pressure over northern Minnesota. Strong shear profiles were supportive of rotating updrafts which produced damaging wind gusts and an EF1 tornado that moved from extreme northern Kenosha County into eastern Racine County.  For additional related information go to this URL: http://www.crh.noaa.gov/mkx/?n=102610_recordcyclone.

Thunderstorm Wind in JEFFERSON, WISCONSIN
From 26-OCT-10 05:30:00 to 26-OCT-10 05:30:00 (CST-6)
Location: HELENVILLE
Magnitude: 65.00 EG
Property damage: 15.00K
Reported by: NWS Employee

An NWS employee reported multiple homes with roof shingle damage from thunderstorm wind gusts estimated up to 65 knots (75 mph).

Thunderstorm Wind in JEFFERSON, WISCONSIN
From 26-OCT-10 05:40:00 to 26-OCT-10 05:45:00 (CST-6)
Location: LAKE MILLS
Magnitude: 65.00 EG
Property damage: 20.00K
Reported by: Law Enforcement

Law enforcement officials reported numerous trees and power lines blown down by thunderstorm wind gusts estimated up to 65 knots (75 mph) in the city of Lake Mills.

Tornado in KENOSHA, WISCONSIN
From 26-OCT-10 06:47:00 to 26-OCT-10 06:48:00 (CST-6)
Location: SOMERS
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

An EF1 tornado developed about 0.95 mile north of Somers, about 2300 feet southwest of the intersection of County Highway KR (County Line Road) and County Highway EA (72nd Avenue). The tornado moved northeast just under one-half mile in Kenosha County before crossing into southern Racine County about 1.34 miles northeast of Somers at the intersection of CTH EA and County Line Rd. While in Kenosha County it destroyed a 6-vehicle garage and damaged a nearby home, trees, and power lines. The tornado path averaged 50 yards in width, with a maximum width of 100 yards. The EF-rating was based on DI 27(TH) DOD 4 with estimated wind speeds up to 100 mph. The exact start location is Lat 42.66377 Lon -87.89961. The exact end location on the Kenosha-Racine County line is Lat 42.66901 Lon -87.89515.  Property damage values were estimated.

Tornado in RACINE, WISCONSIN
From 26-OCT-10 06:48:00 to 26-OCT-10 06:53:00 (CST-6)
Location: STURTEVANT
Tornado F-scale: EF1
Property damage: 1.00M
Reported by: NWS Storm Survey

An EF1 tornado that developed in far northern Kenosha County, northeast of Somers, entered Racine County near the intersection of County Highway KR (County Line Road) and 90th Street. After a path length of about 0.43 mile in Kenosha County, it crossed into Racine County where CTH EA (72nd Ave) intersects County Line Rd. The tornado moved northeast and dissipating in the northeast section of Graceland Cemetery on the west side of the City of Racine, about 500 feet west of Osborne Boulevard. In Racine County, the tornado blew a weakly anchored barn (built in the 1920s) off its foundation and damaged an industrial building south of STH 11.  Later on, it tore off a 100'x200' roof section of the Case/New Holland building, damaged several HVAC units on the roof, and tore off some of the building's garage doors. The Case/New Holland plant was closed until Monday, November 1st while the roof was being repaired.  Two workers in this plant were injured by the tornadoes effects. Additionally, a tractor and it's semi-trailer on the Case/New Holland site were blown over and damaged.  wo other businesses on STH 11 reported roof damage.  At least 3 homes sustained damage. State Highway 11 was closed for a time in eastern Racine County due to debris and fallen power lines, closing or disrupting business at stores along Highway 11, especially in the 7000 and 7100 blocks.  At a church 2 miles northeast of the intersection of STH 11 and Oakes Rd., damage was inflicted to its roof, siding windows and a brick sign.  Numerous trees and a few power lines were blown down or broken along the path of the tornado. At one point, about 2700 customers lost electrical power. There were reports of a couple vehicle accidents as drivers tried to avoid the tornado.  The tornado path averaged 50 yards in width, with a maximum width of 100 yards. The EF-rating was based on DI 23 DOD 4 EXP103 with estimated wind speeds up to 105 mph. The exact start location in Racine County is Lat 42.66901 Lon -87.89515. The exact end location is Lat 42.72845 Lon -87.82596.  The path of the tornado was not a straight line, rather, a rough curved line with an actual path length of 5.92 miles within Racine County.  After crossing STH 11 about 1/10 of a mile east of North Branch Pike River, the tornado path bearing changed from NNE to NE.  Property damage values are estimated.

Thunderstorm Wind in KENOSHA, WISCONSIN
From 26-OCT-10 06:46:00 to 26-OCT-10 06:46:00 (CST-6)
Location: KENOSHA AIRPORT
Magnitude: 59.00 MG
Reported by: ASOS

The ASOS at the Kenosha airport recorded a thunderstorm wind gust of 59 knots (68 mph) with sustained winds of 43 knots (49 mph). Trees were reported blown down in the vicinity from the thunderstorm wind gusts.

Thunderstorm Wind in ROCK, WISCONSIN
From 26-OCT-10 05:07:00 to 26-OCT-10 05:15:00 (CST-6)
Location: DOWNTOWN JANESVILLE
Magnitude: 65.00 EG
Reported by: Law Enforcement

County sheriff deputies reported numerous trees blown down by thunderstorm wind gusts estimated up to 65 knots (75 mph). Construction barrels were scattered along Interstate 90.

Thunderstorm Wind in ROCK, WISCONSIN
From 26-OCT-10 05:35:00 to 26-OCT-10 05:35:00 (CST-6)
Location: BELOIT
Magnitude: 65.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

A trained spotter reported sections of a partially destroyed billboard entangled in power lines at the intersection of Milwaukee Road and Freeman Parkway by thunderstorm wind gusts estimated up to 65 knots (75 mph).