Alert archive / Illinois / Severe Thunderstorm Watches in 2005
Severe Thunderstorm Watch 729
The Storm Prediction Center issued this severe thunderstorm watch at Aug 18, 2005, 9:25 AM CDT for 14 counties in Illinois; Lake County, Porter County, Indiana; Berrien County, Michigan. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 18, 2005, 9:25 AM CDT (14:25 UTC)
- Expired
- Aug 18, 2005, 3:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
Counties Boone County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Marshall County, IL, McHenry County, IL, Putnam County, IL, Will County, IL, Lake County, IN, Porter County, IN, Berrien County, MI
The radar
The Chicago radar (KLOT), 34 km from the middle of the area, began a volume at 14:24 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.
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 18, 10:14 AM CDT | Severe Thunderstorm Warning | LOT | DeKalb, Lee | 19 min |
| Aug 18, 10:53 AM CDT | Severe Thunderstorm Warning | ILX | Marshall | 40 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, 2.4 hours before the alert went out and 193 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
- 757 J/kg
- Mixed-layer CIN
- -54 J/kg
- Mixed-layer LCL
- 763 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 212 m²/s²
- 0-3 km storm-relative helicity
- 226 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 5.9
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 9:00 AM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, Cook, DeKalb, DeWitt and 34 more | 2 hr |
| Aug 18, 1:16 PM CDT | Mesoscale Discussion | SPC | Ford, Grundy, Iroquois, Kankakee, Kendall, LaSalle and 2 more | 89 min |
| Aug 18, 2:09 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, Henry, Jo Daviess, Lee and 6 more | 96 min |
| Aug 18, 4:49 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Hancock, Pike, Schuyler | 116 min |
| Aug 18, 5:35 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Cass, Fulton, Greene, Hancock and 9 more | 6 hr |
Nearby
Severe Thunderstorm Watches in Illinois, 2005Severe Thunderstorm Watches in Indiana, 2005Severe Thunderstorm Watches in Michigan, 2005Every severe thunderstorm watch in 2005
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.