- Western Wisconsin Derecho
The Western Wisconsin Derecho was a
derecho , or severe weather system, that occurred through several counties of WesternWisconsin onJuly 15 1980 . It caused nearly $160M in damage (1980 dollars) and one person was killed. At the time, it was considered the worstnatural disaster in Wisconsin history, and likely still is. To this day, the storm is still referred to as "The July 15th (1980) Storm," "July 15th, 1980," or simply "The Storm."The system formed in central
Minnesota during the early evening ofJuly 15 and intensified that evening in the eastern part of the state. It was a rapidly-moving storm, roaring through the Twin Cities at 60 mph (97 km/h), and picked up speed as it entered Wisconsin.Prelude
The
15 July storm developed during the devastating heat wave of 1980. Eight of the previous nine days in the Twin Cities had highs above 90°F (32°C). The high on11 July was 100°F (38°C). On14 July , the day before the storm, the high was 99°F (37°C); the overnight low was a sticky 79°F (26°C). Conditions for severe weather had clearly been developing for days.The storm
At 2:00 pm on the afternoon of
July 15 , a weak area of low pressure was stationed over easternSouth Dakota , adjacent to a warm front that extended southeast through southern Minnesota into easternIowa . Ahead (north) of the warm front was an area of hot, dry air: the high temperature for the day at Eau Claire was 94°F (34°C) and 95°F (35°C) in the Twin Cities. South of the front was very humid, hot air:Cedar Rapids, Iowa had a high temperature of 98°F (37°C).As the afternoon progressed, the warm front moved into the dryer air to the north, pulling with it the moist air over the dry air. Regional meteorologists were aware of the potential for thunderstorms because of the low pressure system and the intense heat and moisture, but no one could have predicted the storm that would develop that night.
As the storm raced through St Croix, Pierce, Dunn, Eau Claire, Chippewa, and Clark counties, it caused a band of damage more than 20 miles (30 km) wide. A maximum wind speed of 110 mph (177 km/h) was recorded at the
Chippewa Valley Regional Airport , while 100 mph wind was recorded in the city of Eau Claire. At 9:39 p.m., WEAU-TV broadcast an alert from theNational Weather Service about one of several tornado warnings that evening for Eau Claire County; moments later, the station lost power and wentoff-the-air .By 10:00 p.m., with the most intense part of the storm winding down, the area of low pressure was directly over western Wisconsin. Behind the low, air had cooled considerably, with the Twin Cities reporting temperatures in the upper 60s. In addition to being tremendously destructive, the storm was considerably long-lived. Remnants of the storm continued through western
Michigan ; only in theDetroit area did it finally dissipate.Tornadoes
Although much of the storm's damage was caused by straight-line winds (see
downburst ), severaltornadoes were reported.Tornado Chart
Total = 10
F0 = 2
F1 = 4
F2 = 3
F3 = 1
F4 = 0
F5 = 0
Enhanced=noJuly 15 event
Aftermath
One area of Eau Clare that was hit hardest was the Mill Run subdivision, then a part of the Town of Union, now a neighborhood on the city's north side. Many homes in the neighborhood were destroyed. Across US-12 from Mill Run are the headquarters of the home improvement retailer
Menards , which also sustained major damage.Farm losses
Farm property was hit very hard, with Dunn County receiving the worst damage. It was estimated that more than $27M of damage was done just to farm buildings in that county, and $8M in crops. More than 10,000 farms were initially without power after the storm.
Political controversy
Four counties affected by the storm were declared
federal disaster area s on24 July by President Carter. Approximately $3.3M of public property in Eau Claire County was damaged in the storm.FEMA would have covered that entire amount in theory. But at some point that year, the rule was changed on what FEMA would cover – which amounted to only 75%. That left better than $800,000 for Wisconsin to pay. No one notified the states when the rule was changed.Theories for the change in coverage include the massive influx of Cubans into the country; the Mount St Helens eruption of
18 May ; the severe tornadoes inGrand Island, Nebraska in June; and flooding in westernPennsylvania during August. The federal government's budget was badly impacted by these and other disasters. In all, there were 22 major disaster declarations in 1980.Compounding problems for the state was that the storm occurred in an election year. Frustrated Wisconsin officials, including Governor Lee Dreyfus, were not prepared for the difficulty in dealing with the federal government during such a time.
Property damage (1980 estimates)
* Total damage was estimated at $159,522,650. This highly localized damage estimate significantly exceeds all more recent natural disasters, such as the
2007 Midwest flooding , which affected six Midwestern states.
** Eau Claire County: $60,983,650
** Dunn County: $38,572,000
** Pierce County: $29,557,000
** Chippewa County: $10,675,000
**Public property : $7,359,500
** Timber Losses: $14,518,000See also
*
List of derecho events External links
* [http://climate.umn.edu University of Minnesota Climatology Working Group]
* [http://www.fema.gov/news/disasters.fema?year=1980 1980 Federal Disaster Declarations (FEMA)]
* [http://www.tornadoproject.com/alltorns/witorn.htm Tornado Project Online]
* [http://www.lukaslight.com "The Storm of 1980"] by Lukas Hoffland
*"The Storm" (television program) aired 21 July 1980 onWEAU-TV
*"The Storm: One Year Later" (television program) aired 15 July 1981 onWEAU-TV
* [http://www.chippewa.com/articles/2005/07/06/news/news1.txt 1980 storm's ferocity unforgettable] - newspaper article
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