July 2011 Midwest derecho
 Radar loop of the derecho (Click to animate) | |
| Date(s) | July 11, 2011 |
|---|---|
| Duration | 18 hours |
| Peak wind gust (measured) | 130 mph (209 km/h; 58.1 m/s) (Vinton, Iowa) |
| Tornado count | 1 |
| Strongest tornado1 | EF0 tornado |
| Fatalities | 1[1] |
| Areas affected | Iowa, Illinois, Michigan, Ohio |
| 1Most severe tornado damage; see Enhanced Fujita scale | |
A destructive
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 and ended around 18 hours later somewhere in the Atlantic Ocean. In Iowa, wind speeds topped out at 130 miles per hour (210 km/h) around Vinton and Garrison.[3]
In Garrison, straight line wind of 110–130 miles per hour (180–210 km/h) 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.[4]
At Vinton, straight line wind in excess of 110 miles per hour (180 km/h) caused damage to numerous roof structures and some exterior walls, including a downtown apartment building. Nearly every tree was significantly damaged or snapped off.
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.[5]
In Chicago, this derecho injured six people in the collapse of a festival tent and left more than 860,000 people without electricity.[1][6]
Confirmed tornadoes
| EFU | EF0 | EF1 | EF2 | EF3 | EF4 | EF5 | Total |
|---|---|---|---|---|---|---|---|
| 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
July 11 event
| EF# | Location | County / Parish | State | Start Coord. | Time (UTC) | Path length | Max width | Summary |
|---|---|---|---|---|---|---|---|---|
| EF0 | SE of Moorland | Webster | IA | 42°25′N 94°17′W / 42.42°N 94.28°W | 07:52–07:56 | 2.21 miles (3.56 km) | 50 yards (46 m) | Intermittent tornado touchdown with damage to crops.[7] |
See also
- List of derecho events
- Tornadoes of 2011
- June 2012 North American derecho
- August 2020 Midwest derecho
Notes
- ^ All dates are based on the local time zone where the tornado touched down; however, all times are in Coordinated Universal Time for consistency.
References
- ^ a b c "The Cross-Country Derecho of July 2011". NOAA.
- ^ "July 11, 2011 East Central Iowa Derecho". NOAA.
- ^ "Rare "Derecho" left mark on Iowa Monday". Radio Iowa. July 12, 2011.
- ^ a b "July 11, 2011 East Central Iowa Derecho and Severe Wind". NOAA.
- ^ "11 July 2011 Severe Weather Summary". NOAA.
- ^ Janssen, Kim, Mitch Dudek and Stefano Esposito, "Storm could break ComEd record with 860,000-plus losing power," Chicago Sun-Times, July 11, 2011.
- ^ "Iowa Event Report: EF0 Tornado". National Weather Service. National Centers for Environmental Information. Retrieved August 19, 2020.