Alert archive / Wisconsin / Tornado Watches in 2009
Tornado Watch 715
The Storm Prediction Center issued this tornado watch at Aug 19, 2009, 4:49 PM CDT for 4 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 19, 2009, 4:49 PM CDT (21:49 UTC)
- Expired
- Aug 19, 2009, 9:50 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 59 counties
Allamakee 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, Muscatine County, IA, Scott County, IA, Winneshiek County, IA, Bureau County, IL, Carroll County, IL, Henry County, IL, Jo Daviess County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL, Fillmore County, MN, Houston County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Barron County, WI, Buffalo County, WI, Burnett County, WI, Chippewa County, WI, Clark County, WI, Crawford County, WI, Dunn County, WI, Eau Claire County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Lafayette County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Price County, WI, Richland County, WI, Rusk County, WI, Saint Croix County, WI, Sauk County, WI, Sawyer County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Washburn County, WI
The radar
The La Crosse radar (KARX), 46 km from the middle of the area, began a volume at 21:53 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 5:13 PM CDT | Tornado Warning | MPX | Barron, Dunn, Polk, Saint Croix | 47 min |
| Aug 19, 5:20 PM CDT | Tornado Warning | ARX | Allamakee | 31 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
Minneapolis, MN (KMPX), launched 12:00Z, 9.8 hours before the alert went out and 196 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
- 368 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 615 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 121 m²/s²
- 0-3 km storm-relative helicity
- 68 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 3.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 11:51 AM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Bureau, Calhoun, Cass and 45 more | 114 min |
| Aug 19, 12:49 PM CDT | Tornado Watch | SPC | Adams, Brown, Bureau, Cass, Champaign, Christian and 52 more | 6 hr |
| Aug 19, 3:05 PM CDT | Tornado Watch | SPC | Champaign, Christian, Coles, Douglas, Edgar, Moultrie and 2 more | 2 hr |
| Aug 19, 3:19 PM CDT | Mesoscale Discussion | SPC | Champaign, Christian, Clark, Coles, Cumberland, DeWitt and 22 more | 86 min |
| Aug 19, 5:11 PM CDT | Tornado Watch | SPC | Clark, Clay, Crawford, Cumberland, Effingham, Jasper and 2 more | 5 hr |
| Aug 19, 4:34 PM CDT | Mesoscale Discussion | SPC | Allamakee, Clayton, Delaware, Dubuque, Jackson, Jones and 1 more | 56 min |
| Aug 19, 5:19 PM CDT | Mesoscale Discussion | SPC | Adams, Buena Vista, Cass, Cherokee, Crawford, Fremont and 14 more | 26 min |
| Aug 19, 5:32 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 43 more | 6 hr |
Nearby
Tornado Watches in Wisconsin, 2009Tornado Watches in Iowa, 2009Tornado Watches in Illinois, 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.