National Weather Service United States Department of Commerce

April 27, 1984 Killer Tornado Outbreak

During the late afternoon of April 27, 1984, multiple supercell thunderstorms developed ahead of a strong cold front that moved across Wisconsin. Ten tornadoes were reported across the state, including three killer tornadoes: One in northern Wisconsin near St. Germain, one west of Appleton, and the third in southeast Wisconsin in Waukesha County. This outbreak of killer tornadoes was one of the bigger outbreaks in northeast Wisconsin since accurate tornado records began in 1950.

Map of Wisconsin tornadoes on April 27, 1984 - Click for large image Newspaper

The Fox Valley Tornado
Around 3:20 pm, a tornado formed near the town of Butte des Morts in northern Winnebago County and quickly intensified into a destructive tornado. The violent storm moved northeast across the town of Clayton, killing one person and destroying many houses. The tornado continued to track northeast toward the northwest side of the city of Appleton. By about 3:40 pm, the tornado wreaked havoc across the western edge of the Outagamie County Airport and near the town of Greenville. The tornado finally dissipated near Freedom.

Fox Valley tornado track map - Click for larger image
Tornado path near Appleton. Appleton-area tornado. Photo by Richard Walbrun.

An estimated two dozen homes were destroyed and many more were damaged across the Fox Valley that afternoon. The storm killed one person and injured 19 more. Total cost of the destruction over the Fox Valley was $2.5 million ($15 million in today’s dollars). The tornado traveled on the ground at about 40 mph and, for a short time, was over one quarter mile wide. The twister was on the ground for 17 miles. It was classified as an F4 tornado, now referred to as an EF4 on today’s Enhanced Fujita Scale (wind speeds of 166-200 mph). 

Other Tornadoes in Northeast Wisconsin that Day
In addition to the Fox Valley tornado, five other tornadoes were reported across central and northeast Wisconsin that day. An F3 tornado, with winds estimated near 140 mph, tore through Oneida and Vilas counties, killing one person south of St. Germain and injuring eight others. Another F3 tornado was reported across Waupaca, Shawano, and Menominee counties causing considerable damage. Other tornados were observed over Wood, Portage, and Langlade counties.