A destructive
derecho event struck the states of
Iowa,
Illinois,
Michigan, and
Ohio on July 11, 2011 and was the most damaging portion of a much larger derecho event known as The Cross Country Derecho of July 2011. It started on the morning of July 11, 2011 when a powerful long-lasting straight-line windstorm, known as a derecho, developed over central Iowa and carved a path of extensive damage across east central Iowa. The storms first took shape as a cluster of low end severe storms over
Southern Nebraska during the late afternoon of July 10. The system continued northeastward and entered western Iowa at 1:00 a.m, still only as a marginal line of severe storms. As the system passed through the
Northern Des Moines metro area at 3:30 a.m., it interacted with an outflow boundary from the storms to the north and rapidly intensified as it accelerated eastward. Over the next hour and a half the storm plowed eastward through
Story,
Marshall, and
Tama Counties, blasting the area with winds of up to . The storm continued to track eastward, plowing through eastern Iowa and the
Southern Great Lakes region before dissipating in
West Virginia in the mid-afternoon. Thousands of trees were downed in western Iowa alone, and numerous structures were either damaged or destroyed. The peak winds were estimated to be in the range of , equal to a
Category 4 hurricane
Category, plural categories, may refer to:
Philosophy and general uses
*Categorization, categories in cognitive science, information science and generally
*Category of being
* ''Categories'' (Aristotle)
*Category (Kant)
*Categories (Peirce)
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. One man was killed in
Grand Rapids, Michigan due to a falling tree.
Shortly after this complex, a
major heat wave would affect the eastern half of the continent, with another significant derecho event occurring on July 17, 2011 over
Ontario,
Quebec and
Northern New England.
Iowa
The derecho started around 3:20 a.m. on Monday morning just north of
Des Moines
Des Moines () is the capital and the most populous city in the U.S. state of Iowa. It is also the county seat of Polk County. A small part of the city extends into Warren County. It was incorporated on September 22, 1851, as Fort Des Moines, ...
and ended around 18 hours later somewhere in the
Atlantic Ocean. In
Iowa, wind speeds topped out at around
Vinton and
Garrison
A garrison (from the French ''garnison'', itself from the verb ''garnir'', "to equip") is any body of troops stationed in a particular location, originally to guard it. The term now often applies to certain facilities that constitute a mil ...
.
In Garrison, straight line wind of produced widespread damage to structures. Many roofs were partially or fully removed and the walls of some buildings collapsed, including the fire station and town library. Nearly every tree was significantly damaged or snapped off. Power outages were widespread.
At Vinton, straight line wind in excess of caused damage to numerous roof structures and some exterior walls, including a downtown apartment building. Nearly every tree was significantly damaged or snapped off.
The
Iowa Braille and Sight Saving School was also severely damaged. The local high school was utilized as an emergency shelter for two or three days after the storm until power was restored throughout the community. The building which housed several newspapers produced locally was damaged and forced the operation to be relocated for several months. In the Dudgeon Lake Wildlife Management Area across the
Cedar River north of Vinton, extensive damage was left in the wake of the derecho with more than half of the trees badly damaged. Some estimated it would take 500 years for the area to fully recover.
Illinois
During the morning hours of July 11, 2011, the line of severe thunderstorms moved very quickly across
Northern Illinois and
Southern Lake Michigan, producing widespread wind damage. In addition, the strong thunderstorm winds with this system generated a classic
seiche event on the lake. A seiche is a situation where lake water ahead of the storms is piled up along the downwind shore (in this case
Indiana and
Michigan) and then sloshes back and forth across the lake for several hours.
In
Chicago, this derecho injured six people in the collapse of a festival tent and left more than 860,000 people without electricity.
[Janssen, Kim, Mitch Dudek and Stefano Esposito]
"Storm could break ComEd record with 860,000-plus losing power,"
''Chicago Sun-Times'', July 11, 2011.
Confirmed tornadoes
See also
*
List of derecho events
The following is a list of derecho events.
North America
Europe
South America
Asia
See also
* Bow echo
* Line echo wave pattern
* List of deadliest Storm Prediction Center days by outlook risk level
* List of microbursts
...
*
Tornadoes of 2011
*
June 2012 North American derecho
*
August 2020 Midwest derecho
Notes
References
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2011-07 Midwest
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F0 and F1 tornadoes
Tornadoes in Iowa
Derecho, 07
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Midwest derecho