Alert archive / Iowa / Severe Thunderstorm Watches in 2001
Severe Thunderstorm Watch 160
The Storm Prediction Center issued this severe thunderstorm watch at Apr 20, 2001, 11:15 PM CDT for 50 counties in Iowa; 11 counties in Minnesota. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2001, 11:15 PM CDT (04:15 UTC)
- Expired
- Apr 21, 2001, 4:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 61 counties
Allamakee County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clarke County, IA, Clayton County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Des Moines County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Henry County, IA, Howard County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mitchell County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Steele County, MN, Waseca County, MN, Winona County, MN
The radar
The La Crosse radar (KARX), 149 km from the middle of the area, began a volume at 04:14 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
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 11:32 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas | 43 min |
| Apr 20, 11:54 PM CDT | Severe Thunderstorm Warning | DMX | Hancock | 31 min |
| Apr 20, 11:59 PM CDT | Severe Thunderstorm Warning | DMX | Polk, Story | 46 min |
| Apr 20, 11:59 PM CDT | Severe Thunderstorm Warning | DMX | Hamilton | 46 min |
| Apr 21, 12:25 AM CDT | Severe Thunderstorm Warning | DMX | Franklin, Hardin | 40 min |
| Apr 21, 12:47 AM CDT | Severe Thunderstorm Warning | DMX | Butler | 38 min |
| Apr 21, 12:51 AM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo | 24 min |
| Apr 21, 12:57 AM CDT | Severe Thunderstorm Warning | DMX | Grundy | 38 min |
| Apr 21, 1:02 AM CDT | Severe Thunderstorm Warning | ARX | Floyd, Mitchell | 58 min |
| Apr 21, 1:13 AM CDT | Severe Thunderstorm Warning | DMX | Bremer | 42 min |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 4.3 hours before the alert went out and 206 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
- 1262 J/kg
- Mixed-layer CIN
- -84 J/kg
- Mixed-layer LCL
- 1387 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -8 m²/s²
- 0-3 km storm-relative helicity
- -15 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.2
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 8:15 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 29 more | 6 hr |
| Apr 20, 8:15 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Clarke, Decatur, Fremont, Mills, Montgomery and 4 more | 6 hr |
Nearby
Severe Thunderstorm Watches in Iowa, 2001Severe Thunderstorm Watches in Minnesota, 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.