Alert archive / Illinois / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 596
The Storm Prediction Center issued this severe thunderstorm watch at Aug 14, 2007, 2:45 AM CDT for 33 counties in Illinois; 18 counties in Iowa. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 14, 2007, 2:45 AM CDT (07:45 UTC)
- Expired
- Aug 14, 2007, 7:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 70 kt
All 51 counties
Benton County, IA, Cedar County, IA, Clinton County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, Cass 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, Menard County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Schuyler County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Woodford County, IL
The radar
The Quad Cities radar (KDVN), 31 km from the middle of the area, began a volume at 07:49 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
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 3:09 AM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 66 min |
| Aug 14, 4:03 AM CDT | Severe Thunderstorm Warning | LOT | Ogle | 42 min |
| Aug 14, 4:44 AM CDT | Severe Thunderstorm Warning | LOT | Ogle | 28 min |
| Aug 14, 5:00 AM CDT | Severe Thunderstorm Warning | LOT | DeKalb, Lee | 35 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 00:00Z, 7.8 hours before the alert went out and 35 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
- 396 J/kg
- Mixed-layer CIN
- -144 J/kg
- Mixed-layer LCL
- 1368 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 184 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 1:23 AM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, DeKalb, Henry, Jo Daviess and 9 more | 67 min |
| Aug 14, 5:13 AM CDT | Severe Thunderstorm Watch | SPC | Grundy, Kane, Kankakee, Kendall, Will | 86 min |
| Aug 14, 5:43 AM CDT | Mesoscale Discussion | SPC | Brown, Bureau, Cass, DeWitt, DuPage, Ford and 28 more | 62 min |
| Aug 13, 9:45 PM CDT | Severe Thunderstorm Watch | SPC | Allamakee, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 11 more | 6 hr |
| Aug 13, 11:35 PM CDT | Mesoscale Discussion | SPC | Allamakee | 85 min |
| Aug 14, 3:32 AM CDT | Mesoscale Discussion | SPC | Allamakee, Black Hawk, Bremer, Buchanan, Butler, Chickasaw and 7 more | 28 min |
| Aug 14, 3:05 PM CDT | Mesoscale Discussion | SPC | Adair, Audubon, Benton, Black Hawk, Boone, Calhoun and 28 more | 85 min |
| Aug 14, 6:54 PM CDT | Mesoscale Discussion | SPC | Adair, Appanoose, Audubon, Boone, Calhoun, Carroll and 35 more | 66 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2007Severe Thunderstorm Watches in Iowa, 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.