Alert archive / Iowa / Tornado Watches in 2009
Tornado Watch 619
The Storm Prediction Center issued this tornado watch at Jul 24, 2009, 5:02 PM CDT for 15 counties in Illinois; 21 counties in Iowa; 5 counties in Wisconsin. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 24, 2009, 5:02 PM CDT (22:02 UTC)
- Expired
- Jul 24, 2009, 11:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 41 counties
Allamakee County, IA, Benton County, IA, Buchanan County, IA, Cedar County, IA, Chickasaw 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, Keokuk County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Winneshiek County, IA, Bureau County, IL, Carroll County, IL, Ford County, IL, Henry County, IL, Jo Daviess County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Mercer County, IL, Ogle County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL, Crawford County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI
The radar
The Quad Cities radar (KDVN), 108 km from the middle of the area, began a volume at 22:02 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
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 50%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
33 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 5:10 PM CDT | Severe Thunderstorm Warning | ARX | Fayette, Winneshiek | 65 min |
| Jul 24, 5:16 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess, Stephenson | 59 min |
| Jul 24, 5:36 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton, Fayette | 69 min |
| Jul 24, 5:39 PM CDT | Flash Flood Warning | ARX | Grant | 2 hr |
| Jul 24, 5:48 PM CDT | Severe Thunderstorm Warning | MKX | Lafayette | 72 min |
| Jul 24, 5:52 PM CDT | Flash Flood Warning | ARX | Allamakee, Clayton, Fayette, Winneshiek | 3 hr |
| Jul 24, 5:59 PM CDT | Severe Thunderstorm Warning | ARX | Grant | 61 min |
| Jul 24, 6:01 PM CDT | Flash Flood Warning | MKX | Lafayette | 3 hr |
| Jul 24, 6:07 PM CDT | Severe Thunderstorm Warning | DVN | Carroll, Jo Daviess, Stephenson | 53 min |
| Jul 24, 6:08 PM CDT | Tornado Warning | ARX | Grant | 34 min |
| Jul 24, 6:10 PM CDT | Tornado Warning | MKX | Lafayette | 38 min |
| Jul 24, 6:12 PM CDT | Severe Thunderstorm Warning | LOT | Ogle | 63 min |
| Jul 24, 6:12 PM CDT | Tornado Warning | ARX | Clayton, Fayette | 33 min |
| Jul 24, 6:20 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 70 min |
| Jul 24, 6:22 PM CDT | Severe Thunderstorm Warning | ARX | Fayette | 53 min |
| Jul 24, 6:27 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan, Delaware, Dubuque | 63 min |
| Jul 24, 6:44 PM CDT | Severe Thunderstorm Warning | ARX | Clayton, Fayette | 54 min |
| Jul 24, 6:53 PM CDT | Severe Thunderstorm Warning | DVN | Carroll, Jo Daviess, Stephenson | 82 min |
| Jul 24, 7:13 PM CDT | Severe Thunderstorm Warning | LOT | Lee, Ogle | 16 min |
| Jul 24, 7:30 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan, Delaware, Dubuque, Jackson, Jones, Linn | 60 min |
| Jul 24, 7:41 PM CDT | Severe Thunderstorm Warning | DVN | Carroll, Rock Island, Whiteside | 64 min |
| Jul 24, 7:48 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Cedar, Clinton, Jones, Linn | 62 min |
| Jul 24, 7:51 PM CDT | Flash Flood Warning | DVN | Benton, Buchanan, Delaware, Dubuque, Jackson, Jones and 1 more | 6 hr |
| Jul 24, 7:57 PM CDT | Severe Thunderstorm Warning | LOT | Lee, Ogle | 63 min |
| Jul 24, 8:43 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Cedar, Iowa, Johnson, Jones, Linn and 1 more | 62 min |
| Jul 24, 8:46 PM CDT | Severe Thunderstorm Warning | DVN | Rock Island, Whiteside | 89 min |
| Jul 24, 9:11 PM CDT | Severe Thunderstorm Warning | DVN | Henry, Mercer | 94 min |
| Jul 24, 9:18 PM CDT | Severe Thunderstorm Warning | DVN | Keokuk, Louisa, Washington | 57 min |
| Jul 24, 9:44 PM CDT | Severe Thunderstorm Warning | DVN | Bureau, Putnam | 44 min |
| Jul 24, 9:49 PM CDT | Flash Flood Warning | DVN | Henry, Rock Island, Whiteside | 4 hr |
| Jul 24, 9:54 PM CDT | Severe Thunderstorm Warning | DVN | Mercer | 43 min |
| Jul 24, 9:58 PM CDT | Severe Thunderstorm Warning | LOT | LaSalle, Livingston | 47 min |
| Jul 24, 10:43 PM CDT | Severe Thunderstorm Warning | LOT | Ford, LaSalle, Livingston | 62 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, 10.0 hours before the alert went out and 110 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
- 116 J/kg
- Mixed-layer CIN
- -40 J/kg
- Mixed-layer LCL
- 1036 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 40 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 9:51 AM CDT | Mesoscale Discussion | SPC | Jo Daviess | 54 min |
| Jul 24, 1:12 PM CDT | Tornado Watch | SPC | Rock Island | 4 hr |
| Jul 24, 3:52 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, DeKalb, Henderson, Henry, Jo Daviess and 15 more | 83 min |
| Jul 24, 10:32 AM CDT | Severe Thunderstorm Watch | SPC | Allamakee, Benton, Black Hawk, Boone, Bremer, Buchanan and 35 more | 6 hr |
| Jul 24, 2:24 PM CDT | Mesoscale Discussion | SPC | Adair, Benton, Black Hawk, Boone, Bremer, Butler and 35 more | 96 min |
| Jul 24, 6:38 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Boone, Calhoun and 28 more | 97 min |
Nearby
Tornado Watches in Iowa, 2009Tornado Watches in Illinois, 2009Tornado Watches in Wisconsin, 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.