Alert archive / Illinois / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 441
The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2007, 9:05 PM CDT for 41 counties in Illinois. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 21, 2007, 9:05 PM CDT (02:05 UTC)
- Expired
- Jun 22, 2007, 2:33 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 41 counties
Adams County, IL, Brown County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Fulton County, IL, Greene County, IL, Jasper County, IL, Lawrence County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Richland County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL
The radar
The Lincoln radar (KILX), 35 km from the middle of the area, began a volume at 02:05 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
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 9:08 PM CDT | Severe Thunderstorm Warning | LSX | Adams | 52 min |
| Jun 21, 9:27 PM CDT | Severe Thunderstorm Warning | ILX | Marshall, Mason, Peoria, Stark, Tazewell | 48 min |
| Jun 21, 9:53 PM CDT | Severe Thunderstorm Warning | ILX | Fulton | 16 min |
| Jun 21, 10:19 PM CDT | Severe Thunderstorm Warning | ILX | Logan, Mason, Menard | 41 min |
| Jun 22, 12:32 AM CDT | Severe Thunderstorm Warning | ILX | Coles, Douglas | 43 min |
| Jun 22, 1:41 AM CDT | Severe Thunderstorm Warning | LSX | Macoupin, Montgomery | 37 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
Lincoln, IL (KILX), launched 00:00Z, 2.1 hours before the alert went out and 95 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
- 2101 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 1618 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 39 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 8:38 PM CDT | Mesoscale Discussion | SPC | Cass, DeWitt, Fulton, Knox, Logan, McLean and 9 more | 97 min |
| Jun 22, 1:41 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Hancock, Henderson, McDonough, Pike and 2 more | 64 min |
| Jun 22, 5:30 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Calhoun, Clinton, Greene and 9 more | 90 min |
Nearby
Severe Thunderstorm Watches in Illinois, 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.