Alert archive / Iowa / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 534
The Storm Prediction Center issued this severe thunderstorm watch at Jul 18, 2007, 5:35 PM CDT for 31 counties in Illinois; 47 counties in Iowa; 4 counties in Wisconsin. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 18, 2007, 5:35 PM CDT (22:35 UTC)
- Expired
- Jul 18, 2007, 11:07 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 70 kt
All 82 counties
Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Clayton County, IA, Clinton County, IA, Dallas County, IA, Davis County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wright County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, DeWitt County, IL, Fulton County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Woodford County, IL, Grant County, WI, Green County, WI, Lafayette County, WI, Rock County, WI
The radar
The Quad Cities radar (KDVN), 120 km from the middle of the area, began a volume at 22:35 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 95%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 90%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
34 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 5:37 PM CDT | Flash Flood Warning | DMX | Black Hawk | 6 hr |
| Jul 18, 5:37 PM CDT | Severe Thunderstorm Warning | DMX | Story | 53 min |
| Jul 18, 5:48 PM CDT | Severe Thunderstorm Warning | DMX | Grundy, Marshall, Tama | 57 min |
| Jul 18, 5:57 PM CDT | Tornado Warning | DMX | Grundy | 21 min |
| Jul 18, 6:02 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk | 43 min |
| Jul 18, 6:17 PM CDT | Severe Thunderstorm Warning | DVN | Benton | 58 min |
| Jul 18, 6:28 PM CDT | Severe Thunderstorm Warning | DMX | Poweshiek | 62 min |
| Jul 18, 6:29 PM CDT | Severe Thunderstorm Warning | MKX | Lafayette | 46 min |
| Jul 18, 6:34 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 41 min |
| Jul 18, 6:42 PM CDT | Severe Thunderstorm Warning | DVN | Linn | 63 min |
| Jul 18, 6:46 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan | 44 min |
| Jul 18, 7:06 PM CDT | Tornado Warning | DVN | Linn | 39 min |
| Jul 18, 7:09 PM CDT | Severe Thunderstorm Warning | LOT | Winnebago | 57 min |
| Jul 18, 7:12 PM CDT | Severe Thunderstorm Warning | DVN | Johnson | 63 min |
| Jul 18, 7:15 PM CDT | Tornado Warning | DVN | Johnson | 45 min |
| Jul 18, 7:17 PM CDT | Flash Flood Warning | LOT | Boone, Lake, McHenry | 6 hr |
| Jul 18, 7:17 PM CDT | Flash Flood Warning | LOT | Boone, Lake, McHenry, Winnebago | 6 hr |
| Jul 18, 7:21 PM CDT | Flash Flood Warning | DVN | Jo Daviess | 6 hr |
| Jul 18, 7:25 PM CDT | Severe Thunderstorm Warning | DVN | Cedar, Jones | 65 min |
| Jul 18, 7:28 PM CDT | Severe Thunderstorm Warning | DMX | Poweshiek | 16 min |
| Jul 18, 7:35 PM CDT | Tornado Warning | DVN | Jones | 40 min |
| Jul 18, 7:52 PM CDT | Severe Thunderstorm Warning | DVN | Clinton | 53 min |
| Jul 18, 8:00 PM CDT | Flash Flood Warning | DVN | Stephenson | 6 hr |
| Jul 18, 8:06 PM CDT | Severe Thunderstorm Warning | DVN | Scott | 39 min |
| Jul 18, 8:12 PM CDT | Flash Flood Warning | DVN | Jackson | 6 hr |
| Jul 18, 8:30 PM CDT | Flash Flood Warning | DVN | Carroll | 6 hr |
| Jul 18, 8:45 PM CDT | Severe Thunderstorm Warning | LOT | Lee, Ogle | 60 min |
| Jul 18, 8:47 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb | 43 min |
| Jul 18, 9:03 PM CDT | Flash Flood Warning | LOT | DeKalb, Lee, Ogle | 6 hr |
| Jul 18, 9:04 PM CDT | Severe Thunderstorm Warning | DVN | Carroll | 31 min |
| Jul 18, 9:32 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb, LaSalle | 58 min |
| Jul 18, 9:39 PM CDT | Severe Thunderstorm Warning | LOT | Lee | 21 min |
| Jul 18, 9:57 PM CDT | Severe Thunderstorm Warning | DMX | Marshall | 25 min |
| Jul 18, 10:28 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall | 47 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, 10.6 hours before the alert went out and 335 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
- 1891 J/kg
- Mixed-layer CIN
- -18 J/kg
- Mixed-layer LCL
- 641 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- -61 m²/s²
- 0-3 km storm-relative helicity
- 36 m²/s²
- Significant tornado parameter
- -0.2
- Supercell composite
- -1.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 9:31 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Carroll, DeKalb, Jo Daviess, Lee, Ogle and 3 more | 6 hr |
| Jul 17, 11:24 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, DeKalb, Henderson, Henry, Jo Daviess and 15 more | 96 min |
| Jul 18, 3:35 AM CDT | Mesoscale Discussion | SPC | Boone, Carroll, DeKalb, Jo Daviess, Kane, Lee and 5 more | 85 min |
| Jul 18, 4:21 AM CDT | Mesoscale Discussion | SPC | Clark, Clay, Coles, Crawford, Cumberland, Douglas and 10 more | 54 min |
| Jul 18, 4:59 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, Champaign, Cook, DeKalb and 32 more | 91 min |
| Jul 18, 6:38 PM CDT | Mesoscale Discussion | SPC | Champaign, Cook, Douglas, DuPage, Edgar, Ford and 11 more | 97 min |
| Jul 18, 6:50 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, DeKalb, Henderson, Henry and 18 more | 85 min |
| Jul 18, 12:47 PM CDT | Mesoscale Discussion | SPC | Allamakee, Benton, Black Hawk, Bremer, Buchanan, Buena Vista and 37 more | 2 hr |
| Jul 18, 2:09 PM CDT | Severe Thunderstorm Watch | SPC | Black Hawk, Boone, Bremer, Buena Vista, Butler, Calhoun and 33 more | 4 hr |
| Jul 18, 12:17 PM CDT | Mesoscale Discussion | SPC | Barron, Burnett, Chippewa, Clark, Dunn, Eau Claire and 24 more | 118 min |
| Jul 18, 1:37 PM CDT | Severe Thunderstorm Watch | SPC | Brown, Calumet, Dodge, Door, Fond du Lac, Green Lake and 18 more | 7 hr |
| Jul 18, 3:42 PM CDT | Mesoscale Discussion | SPC | Buffalo, Chippewa, Clark, Dunn, Eau Claire, Jackson and 6 more | 63 min |
| Jul 18, 3:59 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 10 more | 5 hr |
| Jul 18, 5:46 PM CDT | Mesoscale Discussion | SPC | Brown, Calumet, Dodge, Fond du Lac, Green Lake, Manitowoc and 11 more | 119 min |
| Jul 18, 6:44 PM CDT | Mesoscale Discussion | SPC | Adams, Jackson, Juneau, La Crosse, Monroe, Trempealeau and 1 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Iowa, 2007Severe Thunderstorm Watches in Illinois, 2007Severe Thunderstorm Watches in Wisconsin, 2007Every severe thunderstorm watch in 2007
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.