An early Fall severe weather outbreak hit parts of central and northern Wisconsin on Thursday October 25, 2012. A broken line of severe thunderstorms developed ahead of a strong cold front during the morning and raced northeast across central and northcentral Wisconsin. Radar data indicated that a bowing line segment ("bow echo" ) developed over eastern Taylor County and raced northeast (at nearly 70 mph) across western and central Marathon County producing damaging winds and large hail. The worst damage occurred over far western Marathon County at a farmstead located about 2 miles east of Colby. Several structures were heavily damaged on the farmstead, including a large barn that had collapsed due to the strong winds. A survey conducted by the Marathon County Emergency Manager indicated that the damage near Colby was the result of straight-line winds. Maximum wind gusts were estimated to be in the 65 to 75 mph range. A separate bowing line segment knocked down several trees near Pickeral in northeast Langlade County. Hail up to an inch in diameter was also reported in the Wausau and Rhinelander areas.
The radar loop (upper-left) illustrates the storm evolution during the height of the event. The radar image on the upper-right is a close-up of the storm about the time it hit the Colby area. Note the "bow" in the line segment just east of Colby. In both images above, the lowest elevation radar reflectivity is on the left panel and the base velocity is on the right.
The map on the upper-left shows the location and type of the severe weather reports during the event. The Google map on the upper-right (Coutesy of Steve Hagman) is a detailed map showing the swath of wind damage that extended from Highway 13 near Colby northeast to Athens.
The photos below (Courtesy of Steve Hagman) show some of the wind damage to the farmstead just east of Colby.