Alert archive / Iowa / Severe Thunderstorm Watches in 1997
Severe Thunderstorm Watch 486
The Storm Prediction Center issued this severe thunderstorm watch at Jun 20, 1997, 4:15 AM CDT for 59 counties in Iowa; Burt County, Nebraska. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 1997, 4:15 AM CDT (09:15 UTC)
- Expired
- Jun 20, 1997, 10:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 60 counties
Allamakee County, IA, Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin 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, Iowa County, IA, Jasper County, IA, Johnson County, IA, Kossuth County, IA, Linn County, IA, Lyon County, IA, Marshall County, IA, Mitchell County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Burt County, NE
The radar
The Des Moines radar (KDMX), 125 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
9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 5:02 AM CDT | Severe Thunderstorm Warning | DMX | Webster | 33 min |
| Jun 20, 5:17 AM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Wright | 33 min |
| Jun 20, 5:48 AM CDT | Severe Thunderstorm Warning | DMX | Franklin, Hardin | 32 min |
| Jun 20, 5:54 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 31 min |
| Jun 20, 6:09 AM CDT | Severe Thunderstorm Warning | DMX | Butler, Grundy | 36 min |
| Jun 20, 6:29 AM CDT | Severe Thunderstorm Warning | FSD | Sioux | 36 min |
| Jun 20, 6:45 AM CDT | Severe Thunderstorm Warning | DMX | Black Hawk | 45 min |
| Jun 20, 7:25 AM CDT | Severe Thunderstorm Warning | DMX | Butler | 35 min |
| Jun 20, 8:28 AM CDT | Severe Thunderstorm Warning | FSD | O'Brien, Osceola | 32 min |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 9.3 hours before the alert went out and 230 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
- 1320 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 2762 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 37 m²/s²
- 0-3 km storm-relative helicity
- 58 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
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 |
|---|---|---|---|---|
| Jun 19, 9:30 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Buena Vista, Calhoun, Carroll, Cherokee, Clay and 21 more | 5 hr |
| Jun 20, 1:00 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 21 more | 5 hr |
| Jun 20, 5:00 AM CDT | Severe Thunderstorm Watch | SPC | Buena Vista, Cherokee, Clay, Dickinson, Emmet, Lyon and 6 more | 5 hr |
| Jun 20, 3:30 PM CDT | Tornado Watch | SPC | Arthur, Banner, Box Butte, Chase, Cherry, Cheyenne and 26 more | 7 hr |
Nearby
Severe Thunderstorm Watches in Iowa, 1997Severe Thunderstorm Watches in Nebraska, 1997Every severe thunderstorm watch in 1997
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.