Alert archive / Illinois / Severe Thunderstorm Watches in 2002
Severe Thunderstorm Watch 627
The Storm Prediction Center issued this severe thunderstorm watch at Aug 21, 2002, 2:25 PM CDT for 20 counties in Illinois; 15 counties in Iowa; 18 counties in Wisconsin. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 21, 2002, 2:25 PM CDT (19:25 UTC)
- Expired
- Aug 21, 2002, 8:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 53 counties
Cedar County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Lee County, IL, Marshall County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jefferson County, WI, Lafayette County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Vernon County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI
The radar
The Quad Cities radar (KDVN), 35 km from the middle of the area, began a volume at 19:24 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
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 3:35 PM CDT | Severe Thunderstorm Warning | DVN | Iowa, Johnson, Washington | 40 min |
| Aug 21, 4:53 PM CDT | Severe Thunderstorm Warning | DVN | Cedar | 52 min |
| Aug 21, 5:10 PM CDT | Severe Thunderstorm Warning | MKX | Iowa, Lafayette | 65 min |
| Aug 21, 5:16 PM CDT | Severe Thunderstorm Warning | MKX | Fond du Lac, Green Lake | 29 min |
| Aug 21, 5:18 PM CDT | Tornado Warning | MKX | Fond du Lac, Green Lake | 57 min |
| Aug 21, 5:25 PM CDT | Severe Thunderstorm Warning | MKX | Columbia, Sauk | 50 min |
| Aug 21, 5:27 PM CDT | Severe Thunderstorm Warning | DVN | Jackson | 33 min |
| Aug 21, 5:54 PM CDT | Severe Thunderstorm Warning | MKX | Columbia, Dane, Marquette | 51 min |
| Aug 21, 6:03 PM CDT | Severe Thunderstorm Warning | DVN | Muscatine | 42 min |
| Aug 21, 6:05 PM CDT | Severe Thunderstorm Warning | DVN | Muscatine | 40 min |
| Aug 21, 6:13 PM CDT | Tornado Warning | DVN | Muscatine | 32 min |
| Aug 21, 6:17 PM CDT | Severe Thunderstorm Warning | MKX | Fond du Lac, Green Lake | 43 min |
| Aug 21, 6:24 PM CDT | Severe Thunderstorm Warning | MKX | Green | 51 min |
| Aug 21, 6:25 PM CDT | Flash Flood Warning | MKX | Fond du Lac | 4 hr |
| Aug 21, 6:39 PM CDT | Tornado Warning | DVN | Scott | 66 min |
| Aug 21, 6:42 PM CDT | Severe Thunderstorm Warning | MKX | Rock | 48 min |
| Aug 21, 6:59 PM CDT | Severe Thunderstorm Warning | LOT | Winnebago | 46 min |
| Aug 21, 7:16 PM CDT | Severe Thunderstorm Warning | MKX | Dane, Jefferson | 59 min |
| Aug 21, 7:29 PM CDT | Severe Thunderstorm Warning | MKX | Walworth | 61 min |
| Aug 21, 7:48 PM CDT | Severe Thunderstorm Warning | MKX | Waukesha | 27 min |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 7.4 hours before the alert went out and 33 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
- 1748 J/kg
- Mixed-layer CIN
- -90 J/kg
- Mixed-layer LCL
- 760 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 173 m²/s²
- 0-3 km storm-relative helicity
- 150 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 7:30 PM CDT | Tornado Watch | SPC | Clay, Dickinson, Lyon, O'Brien, Osceola, Sioux | 6 hr |
Nearby
Severe Thunderstorm Watches in Illinois, 2002Severe Thunderstorm Watches in Wisconsin, 2002Severe Thunderstorm Watches in Iowa, 2002Every severe thunderstorm watch in 2002
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.