Alert archive / Illinois / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 461
The Storm Prediction Center issued this severe thunderstorm watch at Jun 10, 2011, 6:08 PM CDT for 19 counties in Illinois. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 10, 2011, 6:08 PM CDT (23:08 UTC)
- Expired
- Jun 11, 2011, 12:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Cass County, IL, Christian County, IL, DeWitt County, IL, Fulton County, IL, Knox County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Morgan County, IL, Peoria County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Stark County, IL, Tazewell County, IL, Woodford County, IL
The radar
The Lincoln radar (KILX), 43 km from the middle of the area, began a volume at 23:09 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
- 30%
- 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
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 10, 6:20 PM CDT | Severe Thunderstorm Warning | ILX | Cass, Morgan, Scott | 55 min |
| Jun 10, 6:38 PM CDT | Tornado Warning | ILX | Schuyler | 67 min |
| Jun 10, 7:15 PM CDT | Tornado Warning | ILX | Cass, Fulton, Mason, Schuyler | 45 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 12:00Z, 11.1 hours before the alert went out and 100 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
- 581 J/kg
- Mixed-layer CIN
- -228 J/kg
- Mixed-layer LCL
- 670 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 101 m²/s²
- 0-3 km storm-relative helicity
- 130 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 10, 12:10 PM CDT | Mesoscale Discussion | SPC | Champaign, Clark, Clay, Coles, Crawford, Cumberland and 11 more | 95 min |
| Jun 10, 1:02 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Clark, Clay, Clinton, Coles, Crawford and 13 more | 7 hr |
| Jun 10, 3:48 PM CDT | Mesoscale Discussion | SPC | Clark, Clay, Crawford, Cumberland, Edwards, Effingham and 6 more | 87 min |
| Jun 10, 4:57 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Bond, Brown, Calhoun, Clinton, Fayette and 9 more | 7 hr |
| Jun 10, 5:55 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Cass, Champaign, Christian, DeWitt and 20 more | 65 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2011Every severe thunderstorm watch in 2011
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.