Alert archive / Wisconsin / Severe Thunderstorm Watches in 2009
Severe Thunderstorm Watch 682
The Storm Prediction Center issued this severe thunderstorm watch at Aug 9, 2009, 10:21 AM CDT for 14 counties in Illinois; 15 counties in Iowa; 19 counties in Wisconsin. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 9, 2009, 10:21 AM CDT (15:21 UTC)
- Expired
- Aug 9, 2009, 6:00 PM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 70 kt
All 48 counties
Allamakee County, IA, Benton County, IA, Buchanan County, IA, Cedar County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Iowa County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Winneshiek County, IA, Boone County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Jo Daviess County, IL, Kane County, IL, Lake County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Jefferson County, WI, Kenosha County, WI, Lafayette County, WI, Milwaukee County, WI, Ozaukee County, WI, Racine County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI
The radar
The Quad Cities radar (KDVN), 115 km from the middle of the area, began a volume at 15:20 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
22 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 11:31 AM CDT | Severe Thunderstorm Warning | DVN | Benton, Buchanan, Linn | 59 min |
| Aug 9, 12:13 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque, Jones, Linn | 77 min |
| Aug 9, 12:34 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 86 min |
| Aug 9, 12:38 PM CDT | Severe Thunderstorm Warning | ARX | Grant | 62 min |
| Aug 9, 12:55 PM CDT | Severe Thunderstorm Warning | MKX | Lafayette | 95 min |
| Aug 9, 1:29 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess, Stephenson | 61 min |
| Aug 9, 1:44 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Buchanan, Delaware, Jones, Linn | 61 min |
| Aug 9, 1:57 PM CDT | Flash Flood Warning | MKX | Green, Lafayette | 3 hr |
| Aug 9, 2:03 PM CDT | Flash Flood Warning | DVN | Jo Daviess | 6 hr |
| Aug 9, 2:25 PM CDT | Flash Flood Warning | MKX | Rock | 3 hr |
| Aug 9, 2:31 PM CDT | Flash Flood Warning | DVN | Buchanan, Delaware, Dubuque | 6 hr |
| Aug 9, 2:39 PM CDT | Severe Thunderstorm Warning | DVN | Dubuque | 42 min |
| Aug 9, 2:40 PM CDT | Severe Thunderstorm Warning | MKX | Rock | 50 min |
| Aug 9, 2:45 PM CDT | Severe Thunderstorm Warning | ARX | Grant | 45 min |
| Aug 9, 3:01 PM CDT | Severe Thunderstorm Warning | MKX | Iowa, Lafayette, Sauk | 59 min |
| Aug 9, 3:16 PM CDT | Severe Thunderstorm Warning | MKX | Jefferson, Walworth, Waukesha | 44 min |
| Aug 9, 3:40 PM CDT | Severe Thunderstorm Warning | MKX | Kenosha, Milwaukee, Racine, Walworth, Waukesha | 50 min |
| Aug 9, 3:48 PM CDT | Severe Thunderstorm Warning | MKX | Dane, Green, Iowa, Lafayette | 57 min |
| Aug 9, 4:21 PM CDT | Severe Thunderstorm Warning | MKX | Dane, Jefferson, Rock | 54 min |
| Aug 9, 4:22 PM CDT | Flash Flood Warning | MKX | Jefferson, Milwaukee, Racine, Walworth, Waukesha | 105 min |
| Aug 9, 4:47 PM CDT | Severe Thunderstorm Warning | MKX | Jefferson, Walworth, Waukesha | 58 min |
| Aug 9, 5:01 PM CDT | Severe Thunderstorm Warning | MKX | Kenosha, Milwaukee, Racine, Waukesha | 59 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 3.4 hours before the alert went out and 114 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
- 2218 J/kg
- Mixed-layer CIN
- -151 J/kg
- Mixed-layer LCL
- 1047 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 252 m²/s²
- 0-3 km storm-relative helicity
- 276 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 2.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 9:55 AM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Henry, Jo Daviess, Lee, Mercer and 5 more | 35 min |
| Aug 9, 5:52 PM CDT | Severe Thunderstorm Watch | SPC | Bureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 11 more | 8 hr |
| Aug 9, 5:01 AM CDT | Mesoscale Discussion | SPC | Harrison, Monona, Pottawattamie | 59 min |
| Aug 9, 5:16 AM CDT | Severe Thunderstorm Watch | SPC | Harrison, Monona, Pottawattamie, Shelby | 6 hr |
| Aug 9, 6:30 AM CDT | Mesoscale Discussion | SPC | Audubon, Black Hawk, Boone, Bremer, Butler, Calhoun and 30 more | 2 hr |
| Aug 9, 6:54 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Audubon, Black Hawk, Boone, Bremer, Buena Vista and 36 more | 7 hr |
| Aug 9, 11:16 AM CDT | Mesoscale Discussion | SPC | Harrison, Pottawattamie, Shelby | 29 min |
| Aug 9, 1:18 PM CDT | Mesoscale Discussion | SPC | Fremont, Mills, Montgomery, Page, Taylor | 27 min |
| Aug 9, 1:40 PM CDT | Mesoscale Discussion | SPC | Adair, Audubon, Black Hawk, Boone, Bremer, Butler and 23 more | 35 min |
| Aug 9, 3:44 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 32 more | 6 hr |
| Aug 9, 5:49 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Clarke, Davis, Decatur and 18 more | 86 min |
| Aug 8, 8:52 PM CDT | Mesoscale Discussion | SPC | Barron, Dunn, Polk, Saint Croix | 83 min |
| Aug 8, 11:06 PM CDT | Mesoscale Discussion | SPC | Barron, Brown, Calumet, Chippewa, Clark, Dunn and 22 more | 84 min |
Nearby
Severe Thunderstorm Watches in Wisconsin, 2009Severe Thunderstorm Watches in Iowa, 2009Severe Thunderstorm Watches in Illinois, 2009Every severe thunderstorm watch in 2009
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.