<P> On October 26, 2010, the USA recorded its lowest pressure ever in a continental, non-hurricane system, though its pressure was consistent with a category three hurricane . The powerful system was dubbed the "Chiclone" by the media as it hit the Chicago area particularly strongly, as well as Minnesota, Wisconsin and Michigan . It was also meteorologically referred to as a bombogenesis due to the rapid drop of barometric pressure experienced . </P> <P> In Superior, Wisconsin, the storm managed a 28.38 inch reading--a new all - time low for Wisconsin at the time . Near International Falls on the U.S. / Canada border, the system's 28.23 inches of mercury (956 mb) reading established a new all - time Minnesota low pressure . Early Tuesday morning October 26, an F2 tornado rushed through Will County, south of Chicago, at 7: 00 AM . Another tornado is said to have struck Racine, Wisconsin, to the north, but has not yet been confirmed . In Roscoe, IL, about 100 miles to the west of Chicago and 15 minutes north of Rockford, a woman was killed after being crushed under a large tree that fell in her neighborhood of Chickory Ridge . </P> <P> The storm also produced some of the highest officially recorded waves by weather buoys stationed in Lakes Superior and Michigan . Specifically, on Wednesday, October 27, 2010, buoy no . 45136, operated by Environment Canada, in northern Lake Superior recorded a significant wave height of 26.6 feet (this is average height of 1 / 3 of the highest waves over an hour), and buoy no . 45002, operated by the National Data Buoy Center (NDBC), recorded a significant wave height of 21.7 feet in northern Lake Michigan . This would appear consistent with the NOAA forecast for northern Lake Michigan calling for 21--26 - foot waves that day . The persistence and strength of the storm's westerly winds also piled the waters of Lake Michigan along the Michigan shoreline leading to declines in lake levels on the Illinois and Wisconsin side of the lake . Based on NOAA lake level sensors, an updated analysis of Wednesday, October 27, 2010 water levels on Lake Michigan revealed a two - day decrease of 42 inches at Green Bay, WI and 19 inches at Calumet Harbor, IL--- while NOAA sensors at Ludington, MI and Mackinaw City, MI measured lake level rises of 7 and 19 inches respectively . </P> <P> A 78 mph gust was recorded the afternoon of October 27, 2010 at the Harrison - Dever Crib, three miles offshore of Chicago in Lake Michigan, with gusts reaching 63 mph at Chicago's Latin School and in Racine, Wisconsin, 61 mph at Buffalo Grove, Waukegan, Gary and Monroe, Wisconsin and 58 mph at Hinsdale . The storm further whitened sections of the Upper Midwest with the region's first significant snow Tuesday night and Wednesday . Snowfall reports from Minnesota and North Dakota indicate 9 inches fell at Twig, Minn.; 8.5 inches at Dunn Center, N.D.; 8 inches at Adolph, Minn. and Carrington, N.D.; 7.7 inches at Duluth; 4.1 inches Williston; 4 inches at Minot and 3.4 inches at Bismarck--- all in North Dakota . </P>

What is the largest wave ever recorded on lake superior