Alert archive / Illinois / Tornado Watches in 2008
Tornado Watch 234
The Storm Prediction Center issued this tornado watch at Apr 25, 2008, 3:41 PM CDT for 40 counties in Illinois; 10 counties in Iowa. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2008, 3:41 PM CDT (20:41 UTC)
- Expired
- Apr 25, 2008, 8:00 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 50 counties
Cedar County, IA, Clinton County, IA, Des Moines County, IA, Dubuque County, IA, Jackson County, IA, Jones County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Cass County, IL, DeKalb County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kendall 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, McHenry County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Morgan County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Sangamon County, IL, Schuyler County, IL, Scott 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), 51 km from the middle of the area, began a volume at 20:43 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
- 30%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 3:41 PM CDT | Severe Thunderstorm Warning | DVN | Carroll | 64 min |
| Apr 25, 4:07 PM CDT | Tornado Warning | DVN | Carroll, Whiteside | 38 min |
| Apr 25, 4:09 PM CDT | Severe Thunderstorm Warning | LOT | Ogle, Winnebago | 36 min |
| Apr 25, 4:17 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, LaSalle, Livingston | 58 min |
| Apr 25, 4:19 PM CDT | Tornado Warning | DVN | Rock Island | 41 min |
| Apr 25, 4:26 PM CDT | Severe Thunderstorm Warning | LOT | Boone, McHenry | 32 min |
| Apr 25, 4:27 PM CDT | Severe Thunderstorm Warning | DVN | Carroll, Jo Daviess, Stephenson | 63 min |
| Apr 25, 4:37 PM CDT | Severe Thunderstorm Warning | ILX | Cass, Mason, Morgan, Schuyler, Scott | 38 min |
| Apr 25, 5:14 PM CDT | Severe Thunderstorm Warning | ILX | Cass, Mason, Morgan, Scott | 46 min |
| Apr 25, 5:16 PM CDT | Severe Thunderstorm Warning | DVN | Carroll, Jo Daviess, Stephenson | 35 min |
| Apr 25, 5:30 PM CDT | Severe Thunderstorm Warning | ILX | Mason | 32 min |
| Apr 25, 5:36 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 24 min |
| Apr 25, 5:37 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb, LaSalle | 15 min |
| Apr 25, 5:38 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb, Lee, Ogle | 37 min |
| Apr 25, 5:51 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Kane, Lake, McHenry | 45 min |
| Apr 25, 5:59 PM CDT | Severe Thunderstorm Warning | ILX | Morgan, Sangamon | 46 min |
| Apr 25, 6:37 PM CDT | Severe Thunderstorm Warning | ILX | DeWitt, Logan | 38 min |
| Apr 25, 6:43 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, Kendall, Will | 47 min |
| Apr 25, 6:45 PM CDT | Severe Thunderstorm Warning | ILX | DeWitt, Logan, Macon, Sangamon | 30 min |
| Apr 25, 6:51 PM CDT | Tornado Warning | ILX | DeWitt, Logan | 15 min |
| Apr 25, 7:14 PM CDT | Severe Thunderstorm Warning | ILX | Christian, Logan, Macon, Sangamon | 27 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, 8.7 hours before the alert went out and 45 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
- 1215 J/kg
- Mixed-layer CIN
- -45 J/kg
- Mixed-layer LCL
- 678 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 157 m²/s²
- 0-3 km storm-relative helicity
- 204 m²/s²
- Significant tornado parameter
- 1.1
- Supercell composite
- 7.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 4:22 AM CDT | Mesoscale Discussion | SPC | Henderson, Mercer, Rock Island | 23 min |
| Apr 25, 4:51 AM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Carroll, Hancock, Henderson, Henry and 8 more | 5 hr |
| Apr 25, 9:10 AM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Jo Daviess, Lee, Ogle, Rock Island and 3 more | 65 min |
| Apr 25, 12:21 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Carroll, Fulton, Hancock, Henderson and 10 more | 54 min |
| Apr 25, 1:27 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Boone, Brown, Bureau, Calhoun, Carroll and 38 more | 7 hr |
| Apr 25, 3:28 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Henry, Jo Daviess, Knox, Lee and 7 more | 62 min |
| Apr 25, 5:18 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Henry, Jo Daviess, Knox, Lee and 7 more | 57 min |
| Apr 25, 6:01 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Henry, Jo Daviess, Knox, Lee and 7 more | 59 min |
| Apr 25, 12:07 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Cass, Clarke, Dallas, Decatur and 15 more | 7 hr |
| Apr 25, 12:55 AM CDT | Mesoscale Discussion | SPC | Page | 35 min |
| Apr 25, 1:13 AM CDT | Tornado Watch | SPC | Fremont, Montgomery, Page | 5 hr |
| Apr 25, 2:24 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Cass, Clarke, Dallas, Decatur and 14 more | 66 min |
| Apr 25, 3:18 AM CDT | Mesoscale Discussion | SPC | Fremont, Montgomery, Page | 57 min |
Nearby
Tornado Watches in Illinois, 2008Tornado Watches in Iowa, 2008Every tornado watch in 2008
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.