Alert archive / Wisconsin / Tornado Watches in 2009
Tornado Watch 471
The Storm Prediction Center issued this tornado watch at Jun 18, 2009, 8:58 PM CDT for 8 counties in Iowa; 7 counties in Minnesota; 19 counties in Wisconsin. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 18, 2009, 8:58 PM CDT (01:58 UTC)
- Expired
- Jun 19, 2009, 4:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 34 counties
Allamakee County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Dodge County, MN, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Lafayette County, WI, Marquette County, WI, Monroe County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Trempealeau County, WI, Vernon County, WI
The radar
The La Crosse radar (KARX), 13 km from the middle of the area, began a volume at 02:00 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
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
28 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 9:30 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 45 min |
| Jun 18, 9:52 PM CDT | Tornado Warning | ARX | Allamakee | 38 min |
| Jun 18, 9:56 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 42 min |
| Jun 18, 10:00 PM CDT | Severe Thunderstorm Warning | ARX | Juneau, Monroe | 45 min |
| Jun 18, 10:29 PM CDT | Severe Thunderstorm Warning | MKX | Sauk | 46 min |
| Jun 18, 10:30 PM CDT | Severe Thunderstorm Warning | ARX | Crawford, Grant | 45 min |
| Jun 18, 10:36 PM CDT | Severe Thunderstorm Warning | ARX | Monroe, Vernon | 24 min |
| Jun 18, 10:38 PM CDT | Severe Thunderstorm Warning | MKX | Columbia | 52 min |
| Jun 18, 10:59 PM CDT | Severe Thunderstorm Warning | MKX | Iowa, Sauk | 61 min |
| Jun 18, 11:01 PM CDT | Severe Thunderstorm Warning | MKX | Dane | 59 min |
| Jun 18, 11:10 PM CDT | Tornado Warning | MKX | Iowa | 50 min |
| Jun 18, 11:18 PM CDT | Severe Thunderstorm Warning | MKX | Columbia | 42 min |
| Jun 18, 11:25 PM CDT | Severe Thunderstorm Warning | ARX | Grant | 35 min |
| Jun 18, 11:28 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Winneshiek | 32 min |
| Jun 18, 11:44 PM CDT | Flash Flood Warning | MKX | Dane, Iowa, Sauk | 5 hr |
| Jun 18, 11:47 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton | 28 min |
| Jun 18, 11:51 PM CDT | Severe Thunderstorm Warning | MKX | Dane, Green, Iowa, Lafayette | 54 min |
| Jun 18, 11:52 PM CDT | Flash Flood Warning | ARX | Allamakee, Clayton | 6 hr |
| Jun 19, 12:01 AM CDT | Severe Thunderstorm Warning | MKX | Dane, Dodge, Jefferson, Washington, Waukesha | 59 min |
| Jun 19, 12:14 AM CDT | Severe Thunderstorm Warning | ARX | Grant | 25 min |
| Jun 19, 12:18 AM CDT | Severe Thunderstorm Warning | MKX | Dane, Green, Jefferson, Lafayette, Rock | 72 min |
| Jun 19, 12:29 AM CDT | Severe Thunderstorm Warning | MKX | Iowa | 36 min |
| Jun 19, 12:33 AM CDT | Flash Flood Warning | MKX | Kenosha, Racine, Rock, Walworth | 4 hr |
| Jun 19, 12:51 AM CDT | Severe Thunderstorm Warning | MKX | Green, Rock, Walworth | 54 min |
| Jun 19, 12:52 AM CDT | Tornado Warning | MKX | Rock | 53 min |
| Jun 19, 1:11 AM CDT | Tornado Warning | MKX | Rock | 31 min |
| Jun 19, 1:32 AM CDT | Flash Flood Warning | MKX | Green, Lafayette | 4 hr |
| Jun 19, 3:11 AM CDT | Flash Flood Warning | ARX | Grant | 3 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 2.0 hours before the alert went out and 211 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
- 1331 J/kg
- Mixed-layer CIN
- -51 J/kg
- Mixed-layer LCL
- 1216 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 93 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 2.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 8:23 PM CDT | Mesoscale Discussion | SPC | Allamakee, Bremer, Chickasaw, Clayton, Delaware, Dubuque and 5 more | 97 min |
| Jun 19, 1:33 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 26 more | 57 min |
| Jun 19, 2:13 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 40 more | 8 hr |
| Jun 19, 5:01 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 22 more | 59 min |
| Jun 19, 6:58 AM CDT | Mesoscale Discussion | SPC | Benton, Buchanan, Cedar, Clinton, Delaware, Dubuque and 8 more | 62 min |
| Jun 19, 7:14 AM CDT | Severe Thunderstorm Watch | SPC | Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more | 7 hr |
| Jun 19, 12:37 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Benton, Black Hawk, Buchanan and 29 more | 83 min |
| Jun 19, 1:36 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Appanoose, Cass, Clarke, Dallas and 20 more | 4 hr |
| Jun 19, 1:54 PM CDT | Mesoscale Discussion | SPC | Benton, Cedar, Clinton, Delaware, Des Moines, Dubuque and 12 more | 96 min |
| Jun 19, 2:24 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Cedar, Clinton, Des Moines, Dubuque, Henry and 13 more | 8 hr |
| Jun 19, 5:37 PM CDT | Mesoscale Discussion | SPC | Clinton, Des Moines, Scott | 53 min |
| Jun 18, 7:00 PM CDT | Mesoscale Discussion | SPC | Aitkin, Anoka, Benton, Blue Earth, Brown, Carlton and 44 more | 90 min |
| Jun 18, 7:34 PM CDT | Severe Thunderstorm Watch | SPC | Aitkin, Carlton, Cass, Crow Wing, Pine | 6 hr |
| Jun 18, 10:30 PM CDT | Mesoscale Discussion | SPC | Anoka, Benton, Blue Earth, Brown, Carver, Chippewa and 28 more | 60 min |
| Jun 18, 10:53 PM CDT | Severe Thunderstorm Watch | SPC | Anoka, Blue Earth, Brown, Carver, Chisago, Dakota and 22 more | 5 hr |
| Jun 18, 11:07 PM CDT | Mesoscale Discussion | SPC | Columbia, Dane, Dodge, Fond du Lac, Green, Jefferson and 10 more | 53 min |
| Jun 18, 11:30 PM CDT | Severe Thunderstorm Watch | SPC | Dodge, Fond du Lac, Green Lake, Jefferson, Kenosha, Milwaukee and 6 more | 7 hr |
| Jun 19, 2:38 AM CDT | Mesoscale Discussion | SPC | Green, Iowa, Kenosha, Lafayette, Rock, Walworth | 97 min |
| Jun 19, 4:54 PM CDT | Severe Thunderstorm Watch | SPC | Columbia, Dane, Dodge, Fond du Lac, Green, Green Lake and 14 more | 3 hr |
Nearby
Tornado Watches in Wisconsin, 2009Tornado Watches in Iowa, 2009Tornado Watches in Minnesota, 2009Every tornado 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.