Long-duration, widespread, southwesterly high winds raked south-central and southeast Wisconsin for about 36 hours, resulting numerous reports of felled trees, broken tree branches, downed power-lines, and damage to structures and vehicles.  All of this was generated by a record-breaking, low pressure system which tracked northeast from the Central Plains on Monday, October 25, and then rapidly deepened as it moved northeast across northern Minnesota on Tuesday, October 26. The surface low was being driven by a strong negatively-tilted 500 mb trough moving through the central U.S.  A surface weather map at 600 PM October 26th is attached to the Dane County event.  For additional on-line information go to this URL: http://www.crh.noaa.gov/mkx/?n=102610_recordcyclone.
This abnormally strong extra-tropical system broke the record for the lowest sea level pressures measured in the states of Wisconsin and Minnesota. The lowest pressure in Wisconsin occurred at Superior, in far northwest Wisconsin, measuring 961.3 millibars (28.39) at 11:15 AM CDT on the 26th. The previous lowest sea level pressure recorded in Wisconsin was 963.4 millibars (28.45) at Green Bay on April 3 of 1982.
Madison had the second lowest sea level pressure reading on record at 975.3 millibars (28.80 inches of mercury), and Milwaukee had the seventh lowest reading on record at 978.7 millibars (28.90 inches of mercury).
Severe thunderstorms formed along and ahead of a cold front surging eastward ahead of the low. An EF1 tornado formed in northern Kenosha County and tracked northeast across portions of central and eastern Racine County. There were also numerous reports of wind damage from severe thunderstorm winds.  All of this severe weather activity is documented in tornado and thunderstorm wind events for October 26th.  After the cold front passage, strong subsidence in the dry slot of the system produced gradient winds of 22 to 38 knots (25 to 45 mph), with measured gusts to 55 knots (63 mph).  Based on severity of resultant damage, isolated maximum wind gusts may have been as high as 61-64 knots (70-75 mph), especially on ridge tops.
The slow-moving low kept the tight pressure gradient draped across south-central and southeast Wisconsin Wednesday, October 27th. Wind speeds slowed for a time Tuesday night as nocturnal cooling prevented mixing up to the strong winds within 3,000 feet of the ground. However, mixing after sunrise on the 27th tapped these stronger winds, with average mixed-layer winds around 50 knots. Winds at many locations were stronger on Wednesday than Tuesday; with sustained speeds of 26 to 39 knots (30 to 45 mph), and estimated gusts to 56 knots (65 mph). Rural Mutual Insurance reported claims from agricultural producers of one million dollars in damage to buildings and equipment from across all of Wisconsin.  We Energies reported 20,000 customers in Southeast Wisconsin were without power at the peak of the power outages on Tuesday, October 26th.
Below is a county-by-county breakdown (all damage losses are estimated based on variety of sources):
Marquette Co. - Wind gusts blew down trees and power lines across the county.
Green Lake Co. - Wind gusts blew down trees and power lines across the county. A trained spotter in Berlin measured a 62 mph (54 knot) wind gust at 115 pm CDT on October 27th.
Fond du Lac Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in Bryon measured a 60 mph (52 knot) wind gust at 4 pm CDT on October 27th. The maximum 2-minute wind speeds at the Fond du Lac Airport (KFLD) were 38 and 36 mph on the 26th and 27th, respectively.
Sheboygan Co. - Wind gusts blew down trees and power lines across the county. The Sheboygan C-MAN site in the Sheboygan harbor entrance measured a 62 mph (54 knot) wind gust at 1 pm CDT on October 26th. A mesonet site one mile north of downtown Sheboygan measured a 62 mph (54 knot) wind gust at 430 pm CDT on October 27th.  The maximum 2-minute wind speeds at the Sheboygan County Airport (KSBM) were 44 and 46 mph on the 26th and 27th, respectively.
Sauk Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in Baraboo measured a 60 mph (52 knot) wind gust at 1130 am CDT on October 27th. The maximum 2-minute wind speeds at the Lone Rock Airport (KLNR) were 35 and 38 mph on the 26th and 27th, respectively. Just east of Reedsburg, the metal roof of a church storage shed was ripped off. One of shed's support beams crashed through the roof of a the main church building.
Columbia Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in Lodi measured a 59 mph (51 knot) wind gust at 330 pm CDT on October 27th and 50 knots (58 mph) on the 26th. Portage police responded to five wind-related calls, including two downed utility poles and a report of a fallen tree damaging two vehicles.
Dodge Co. - Wind gusts blew down trees and power lines across the county. The RAWS site at Horicon Marsh measured a 53 mph wind gust at a 20-foot height with conversion to the 33-foot standard would bring it to an estimated 61 mph (51 knots) at 101 pm CDT on October 27th. A 53 knot (61 mph) wind gust was measured at a location 5 miles west of Knowles on the 27th. The Dodge County emergency manager reported parts of roofs torn off a couple of pole barns east of Beaver Dam, as well as trees down and shingles blown away.
Washington Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in Bear Valley measured a 62 mph (54 knot) wind gust at 430 pm CDT on October 27th.
Ozaukee Co. - Wind gusts blew down trees and power lines across the county due to wind gusts estimated at 58 mph (50 knots). A large maple tree fell on a portion of a home in Grafton on Wednesday, October 27th, destroying an awning over the front door of the home and damaging roof shingles on the home.
Iowa Co. - Wind gusts blew down trees and power lines across the county due to wind gusts estimated at 58 mph (50 knots). U.S. Highway 18-151 north of Dodgeville was closed from 7 am to 330 pm CDT on Tuesday, October 26th due to downed power lines at the intersection with State Highway 23. Also on the 26th, a large tree fell on a home on West Chapel Street in Dodgeville, severely damaging the roof.
Dane Co. - Wind gusts blew down trees and power lines across the county. A Department of Transportation highway sensor on STH 12 in Madison measured a 62 mph (54 knot) wind gust at 4 pm on October 26th. The wind sensor on top of the 15-story University of Wisconsin Atmospheric, Oceanic and Space Sciences Building in Madison measured a wind gust of 72 mph (63 knots) at 150 pm CDT on October 27th. A semi-trailer truck was rolled over by the winds, blocking the westbound lanes of U.S. Highway 151 in Sun Prairie on the 26th.  A section of the rubber roof on top of the Westgate Mall was peeled back by the strong winds. A tree fell onto a house on Lakeland Ave. on the east side of Madison, and a tree limb damaged the roof of a house on Regent Street on the west side. A large burr oak toppled in the strong winds damaged a barn on the grounds of the Sterling North museum in Edgerton on the 27th.  Even in a sheltered, residential area 5 miles southwest of Downtown Madison, an observer measured wind gusts to 44 knots (51 mph) at 554 pm CDT on the 27th!  At this same location, 1.11 of rain fell on the 26th and a total of 1.54 on Oct 23-24th.  It is possible that the wet surface soils were softened by the rains, making it easier for the high winds to knock down trees.  The maximum 2-minute wind speeds at the Dane County Regional Airport (KMSN) were 30 and 28 mph on the 26th and 27th, respectively.
Jefferson Co. - Wind gusts blew down trees and power lines across the county from wind gusts estimated at 58 mph (50 knots).
Waukesha Co. - Wind gusts blew down trees and power lines across the county from wind gusts estimated up to 60 mph (52 knots). We Energies reported about 1700 customers without power, mainly in the Oconomowoc and Nashota areas at 9 am CDT on October 26th. A large window was blown out at a sporting goods store in Pewaukee. The county mental health center, the Huber Facility, the county communications center and the county highway shop went to emergency back-up power due to the power outages.  The high winds snapped a flag pole at its base at the Hawks Inn Historical Museum in Delafield.  in the city of Waukesha a toppled tree damaged a home.  At the Waukesha Airport (Crites Field) the high winds destroyed part of a roof of a hangar and damaged a door of an adjacent hanger.
Milwaukee Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in Brown Deer measured wind gust of 63 mph (54 knots) at 430 pm on October 27th. The maximum 2-minute wind speeds at the Milwaukee Airport (KMKE) were 44 and 43 mph on the 26th and 27th, respectively. The strong gusts peeled off  exterior wall bricks on two buildings north of downtown Milwaukee along the Milwaukee River. The City of Milwaukee Department of Public Works received 45 calls about broken tree branches, a half dozen reports of minor damage and traffic signals out at a dozen intersections.
Lafayette Co. - Wind gusts blew down trees and power lines across the county from wind gusts estimated up to 58 mph (50 knots).
Green Co. -Wind gusts blew down trees and power lines across the county. A mesonet site in New Glarus measured a wind gust of 62 mph (54 knots) at 340 pm CDT on the 27th.
Rock Co. - Wind gusts, estimated up to 58 mph (50 knots) blew down trees and power lines across the county. A man in Janesville was injured when he was struck by a wind-blown object, possibly a garbage can lid.  He was knocked into his outdoor grill, and received hospital treatment.  School was canceled and students sent home from Janesville Parker High School when portion of the roof was peeled back by the strong winds (estimated repair of $215,000). A garage roof was damaged in Janesville by a large oak limb punching a hole in the roof, and a power pole and power line were downed by the winds near the intersection of Center Ave. and Joliet St. southwest of downtown Janesville.  A massive burr oak tree in Edgerton was blown over and smashed part of roof of a barn on the grounds of the Sterling North museum.
Walworth Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in Elkhorn recorded a 59 mph (51 knot) wind gust at 3 pm CDT on October 27th. Wind-driven rain leaked through the large windows of the atrium at East Troy High School.
Racine Co. - Wind gusts blew down trees and power lines across the county. A mesonet site in the city of Racine reported a 63 mph (55 knot) wind gust at 3 pm CDT on October 27th. The maximum 2-minute wind speeds at the Racine Airport (KRAC) were 36 and 37 mph on the 26th and 27th, respectively. About 4,000 customers in the county were without power. In the city of Racine, embers blown out of a portable fire pit ignited a nearby shed and a neighboring garage on Glendale Ave.  Both the garage and the shed were destroyed. Gilmore Middle School and Wadewitz Elementary School dismissed students for the day around 11 am on Tuesday, October 26th because of power outages at both schools.
Kenosha Co. - Wind gusts blew down trees and power lines across the county, including some road signs. The ASOS at Kenosha County Airport reported a 58 mph (50 knot) wind gust at 344 pm CDT on October 27th. The maximum 2-minute wind speeds at the Kenosha County Airport (KENW) were 49 and 46 mph on the 26th and 27th, respectively.  About 1,700 customers lost power when strong winds snapped four utility poles and downed power lines along County Highway KR in Somers. A garage was leveled by the strong winds in the 200 block of 72nd Avenue in Kenosha.
Lake Michigan waters - a buoy in the nearshore waters of Lake Michigan just east of the city of Racine recorded a 12-foot wave on the 26th and 9-foot wave on the 27th. A buoy east of Washington Island (Door Co.) in the middle of Lake Michigan recorded a 21.7 foot wave on the 26th.

High Wind in MARQUETTE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High Wind in GREEN LAKE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in FOND DU LAC, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in SHEBOYGAN, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in SAUK, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in COLUMBIA, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 51.00 MG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in DODGE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 53.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: RAWS

High Wind in WASHINGTON, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in OZAUKEE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High Wind in IOWA, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High Wind in DANE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 300.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in JEFFERSON, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High Wind in WAUKESHA, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 52.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: NWS Employee

High Wind in MILWAUKEE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 53.00 MG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in LAFAYETTE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High Wind in GREEN, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in ROCK, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High Wind in WALWORTH, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 51.00 MG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in RACINE, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 55.00 MG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in KENOSHA, WISCONSIN
From 26-OCT-10 06:00:00 to 27-OCT-10 18:00:00 (CST-6)
Magnitude: 50.00 MG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: ASOS