Alert archive / Iowa / Mesoscale Discussions in 2011
Mesoscale Discussion 846
The Storm Prediction Center issued this mesoscale discussion at May 21, 2011, 8:55 PM CDT for 74 counties in Iowa; Atchison County, Missouri; 18 counties in Nebraska. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- May 21, 2011, 8:55 PM CDT (01:55 UTC)
- Expired
- May 21, 2011, 10:00 PM CDT
- In force
- 65 min
- Issued by
- the Storm Prediction Center
All 93 counties
Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clarke County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Dickinson County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Fremont County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Howard County, IA, Humboldt County, IA, Ida County, IA, Jasper County, IA, Keokuk County, IA, Kossuth County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Mitchell County, IA, Monona County, IA, Monroe County, IA, Montgomery County, IA, O'Brien County, IA, Osceola County, IA, Page County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Atchison County, MO, Burt County, NE, Cass County, NE, Dodge County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thurston County, NE, Washington County, NE
The radar
The Des Moines radar (KDMX), 97 km from the middle of the area, began a volume at 01:55 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 1.9 hours before the alert went out and 128 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1436 J/kg
- Mixed-layer CIN
- -10 J/kg
- Mixed-layer LCL
- 1205 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 145 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 5.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 22, 4:41 AM CDT | Mesoscale Discussion | SPC | Allamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 28 more | 2 hr |
| May 22, 10:53 AM CDT | Mesoscale Discussion | SPC | Allamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 39 more | 2 hr |
| May 22, 12:07 PM CDT | Tornado Watch | SPC | Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more | 7 hr |
| May 22, 12:51 PM CDT | Tornado Watch | SPC | Appanoose, Benton, Black Hawk, Bremer, Buchanan, Butler and 35 more | 10 hr |
| May 22, 2:59 PM CDT | Mesoscale Discussion | SPC | Allamakee, Benton, Black Hawk, Bremer, Buchanan, Chickasaw and 10 more | 2 hr |
| May 22, 5:47 PM CDT | Mesoscale Discussion | SPC | Cedar, Clinton, Des Moines, Dubuque, Jackson, Johnson and 4 more | 88 min |
| May 21, 7:18 PM CDT | Mesoscale Discussion | SPC | Andrew, Buchanan, Caldwell, Carroll, Chariton, Clay and 23 more | 57 min |
| May 22, 5:18 AM CDT | Mesoscale Discussion | SPC | Dunklin, Pemiscot | 57 min |
| May 22, 1:06 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Benton, Camden, Cedar, Christian and 24 more | 114 min |
| May 22, 1:27 PM CDT | Tornado Watch | SPC | Barry, Barton, Benton, Camden, Cedar, Christian and 23 more | 8 hr |
| May 22, 3:48 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Camden, Cedar and 27 more | 117 min |
| May 22, 6:10 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Camden, Cedar and 27 more | 65 min |
Nearby
Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Nebraska, 2011Mesoscale Discussions in Missouri, 2011Every mesoscale discussion in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.