Alert archive / Iowa / Severe Thunderstorm Watches in 2001
Severe Thunderstorm Watch 129
The Storm Prediction Center issued this severe thunderstorm watch at Apr 11, 2001, 4:00 AM CDT for 27 counties in Iowa; Doniphan County, Kansas; 16 counties in Missouri. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 11, 2001, 4:00 AM CDT (09:00 UTC)
- Expired
- Apr 11, 2001, 9:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 44 counties
Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Greene County, IA, Guthrie County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Ringgold County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Wayne County, IA, Doniphan County, KS, Andrew County, MO, Buchanan County, MO, Caldwell County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Linn County, MO, Livingston County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Sullivan County, MO, Worth County, MO
The radar
The Des Moines radar (KDMX), 127 km from the middle of the area, began a volume at 09:17 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.
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 11, 4:12 AM CDT | Severe Thunderstorm Warning | DMX | Adams, Cass, Taylor | 38 min |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 9.0 hours before the alert went out and 189 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
- 18 J/kg
- Mixed-layer CIN
- -145 J/kg
- Mixed-layer LCL
- 493 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 131 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
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 |
|---|---|---|---|---|
| Apr 11, 2:00 AM CDT | Tornado Watch | SPC | Crawford, Fremont, Harrison, Mills, Monona, Pottawattamie and 1 more | 5 hr |
| Apr 11, 10:45 AM CDT | Tornado Watch | SPC | Adams, Cass, Crawford, Fremont, Harrison, Mills and 8 more | 5 hr |
| Apr 11, 12:00 PM CDT | Tornado Watch | SPC | Adair, Appanoose, Audubon, Benton, Black Hawk, Boone and 46 more | 5 hr |
| Apr 11, 4:00 PM CDT | Tornado Watch | SPC | Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 40 more | 6 hr |
| Apr 10, 8:30 PM CDT | Severe Thunderstorm Watch | SPC | Cheyenne, Decatur, Finney, Gove, Grant, Gray and 18 more | 5 hr |
| Apr 10, 10:15 PM CDT | Severe Thunderstorm Watch | SPC | Ellis, Graham, Hodgeman, Jewell, Mitchell, Ness and 9 more | 6 hr |
| Apr 11, 12:00 AM CDT | Tornado Watch | SPC | Barber, Barton, Clark, Cloud, Comanche, Edwards and 20 more | 4 hr |
| Apr 11, 3:15 AM CDT | Tornado Watch | SPC | Allen, Anderson, Butler, Chase, Chautauqua, Coffey and 13 more | 5 hr |
| Apr 11, 9:30 AM CDT | Tornado Watch | SPC | Doniphan, Johnson, Leavenworth, Miami, Wyandotte | 6 hr |
| Apr 10, 7:00 PM CDT | Severe Thunderstorm Watch | SPC | Audrain, Franklin, Jefferson, Lincoln, Montgomery, Saint Charles and 4 more | 5 hr |
| Apr 11, 6:15 AM CDT | Tornado Watch | SPC | Barry, McDonald, Newton, Stone | 6 hr |
| Apr 11, 10:00 AM CDT | Severe Thunderstorm Watch | SPC | Butler, Carter, Douglas, Howell, Oregon, Ozark and 2 more | 5 hr |
| Apr 11, 1:00 PM CDT | Tornado Watch | SPC | Adair, Audrain, Boone, Callaway, Clark, Cole and 20 more | 6 hr |
Nearby
Severe Thunderstorm Watches in Iowa, 2001Severe Thunderstorm Watches in Missouri, 2001Severe Thunderstorm Watches in Kansas, 2001Every severe thunderstorm watch in 2001
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.