April 4, 1981, West Bend tornado
Encyclopedia
The April 4, 1981, West Bend tornado was a fatal F4
Fujita scale
The Fujita scale , or Fujita-Pearson scale, is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation...

, anticyclonic tornado
Anticyclonic tornado
An anticyclonic tornado is a tornado which rotates in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere. It is simply a naming convention denoting the anomaly from normal rotation which is cyclonic in upwards of 98 percent of tornadoes...

 that struck the Wisconsin city of West Bend in the early morning hours of April 4, 1981. It killed 3 people, and injured another 53. The tornado was largely unexpected and the storm that produced it did not display features of a typical severe storm. Because of this the National Weather Service issued only a Severe Thunderstorm Warning
Severe thunderstorm warning
A severe thunderstorm warning is issued when trained storm spotters or a Doppler weather radar indicate a strong thunderstorm is producing dangerously large hail or high winds, capable of causing significant damage. In the United States, it does not account for lightning or flooding...

 prior to the West Bend Tornado, causing local law enforcement to not sound the tornado sirens in time.

Meteorological synopsis

During the early morning on April 4, 1981 meteorological conditions in Wisconsin were conducive for severe weather. At around 12:00am CST (0600 GMT
Greenwich Mean Time
Greenwich Mean Time is a term originally referring to mean solar time at the Royal Observatory in Greenwich, London. It is arguably the same as Coordinated Universal Time and when this is viewed as a time zone the name Greenwich Mean Time is especially used by bodies connected with the United...

) a thunderstorm
Thunderstorm
A thunderstorm, also known as an electrical storm, a lightning storm, thundershower or simply a storm is a form of weather characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere known as thunder. The meteorologically assigned cloud type associated with the...

 developed and rapidly began to grow over south central Wisconsin. The growing storm caused a downburst
Downburst
A downburst is created by an area of significantly rain-cooled air that, after reaching ground level, spreads out in all directions producing strong winds. Unlike winds in a tornado, winds in a downburst are directed outwards from the point where it hits land or water...

 near the village of Clyman
Clyman, Wisconsin
Clyman is a village in Dodge County, Wisconsin, United States. The population was 388 at the 2000 census. The village is located within the Town of Clyman.-Geography:Clyman is located at ....

 and then continued on towards West Bend. The storm however did not appear to be severe, thunderstorm tops were measured to only be 26000 feet (7,924.8 m) and a weak level 3 bow echo was observed by a radar in Neenah
Neenah, Wisconsin
Neenah is a city on Lake Winnebago in Winnebago County, Wisconsin, United States. Its population was 24,507 at the 2000 census. The city is bordered by, but is politically independent of, the Town of Neenah. Neenah is the southwestern-most of the Fox Cities of Northeast Wisconsin...

. Only a few minutes after midnight (local time) while the storm was weakening the tornado touched down. The tornado was extremely narrow, but it still managed to produce F3 and F4 damage only a few seconds after touching down. It cut a swath of destruction through the city, killing many and injuring hundreds. Post storm analysis determined that not only was the tornado an extremely rare occurrence given the storm's strength, but also that it was an anticyclonic tornado
Anticyclonic tornado
An anticyclonic tornado is a tornado which rotates in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere. It is simply a naming convention denoting the anomaly from normal rotation which is cyclonic in upwards of 98 percent of tornadoes...

. The F4 tornado is one of strongest anticyclonic tornadoes on record.

Impact

The West Bend tornado killed 3 people and injured another 53. It was the most intense tornado to strike Wisconsin in 1981, and caused $25.0 Million in damages. Following the tornado the American Red Cross
American Red Cross
The American Red Cross , also known as the American National Red Cross, is a volunteer-led, humanitarian organization that provides emergency assistance, disaster relief and education inside the United States. It is the designated U.S...

 determined that around 139 structures were damaged or destroyed by the storm. With many residents left homeless and the threat of more storms looming, Governor Lee S. Dreyfus
Lee S. Dreyfus
Lee Sherman Dreyfus was an American politician and member of the Republican Party who served as the 40th Governor of Wisconsin from January 4, 1979 to January 3, 1983....

 declared a state of emergency freeing up the area for aid. The campus of the Moraine Park Technical Institute
Moraine Park Technical College
Moraine Park Technical College is one of 16 technical colleges in the Wisconsin Technical College System and is led by its president, Dr. Sheila Ruhland, and the Moraine Park District Board....

 was severely damaged by the tornado and classes were disrupted.

Aftermath

It was determined that the West Bend police did not activate the city's siren system before or during the tornado. The National Weather Service in Milwaukee issued a Severe Thunderstorm Warning
Severe thunderstorm warning
A severe thunderstorm warning is issued when trained storm spotters or a Doppler weather radar indicate a strong thunderstorm is producing dangerously large hail or high winds, capable of causing significant damage. In the United States, it does not account for lightning or flooding...

 for the area that only mentioned a confirmed tornado touchdown. However because no Tornado Warning
Tornado warning
A tornado warning is an alert issued by government weather services to warn that severe thunderstorms with tornadoes may be imminent. It can be issued after a tornado or funnel cloud has been spotted by eye, or more commonly if there are radar indications of tornado formation...

 was issued for the storm, local police failed to activate the siren. Nearby Dodge County
Dodge County, Wisconsin
Dodge County is a county located in the U.S. state of Wisconsin. As of 2010, the population was 88,759. Its county seat is Juneau.-Geography:According to the U.S...

did activate their siren system after damage reports. The tornado showed the problems with Operational Meteorology or "nowcasting". The storm did not display the typical features of a severe storm and the tornado that was produced formed while the storm was weakening, an almost unheard of event.

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