Alert archive / Illinois / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 553
The Storm Prediction Center issued this severe thunderstorm watch at Jun 25, 2011, 9:30 PM CDT for 10 counties in Illinois. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 25, 2011, 9:30 PM CDT (02:30 UTC)
- Expired
- Jun 26, 2011, 2:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Christian County, IL, Clay County, IL, Crawford County, IL, Cumberland County, IL, Effingham County, IL, Jasper County, IL, Lawrence County, IL, Richland County, IL, Sangamon County, IL, Shelby County, IL
The radar
The Lincoln radar (KILX), 120 km from the middle of the area, began a volume at 02:31 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
- 20%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 60%
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 25, 9:57 PM CDT | Severe Thunderstorm Warning | ILX | Clay, Effingham, Jasper | 63 min |
| Jun 25, 10:02 PM CDT | Severe Thunderstorm Warning | ILX | Christian, Shelby | 58 min |
| Jun 25, 11:07 PM CDT | Flash Flood Warning | ILX | Clay, Cumberland, Effingham, Jasper, Shelby | 6 hr |
| Jun 25, 11:27 PM CDT | Flash Flood Warning | ILX | Clark, Crawford, Cumberland, Jasper | 6 hr |
| Jun 25, 11:31 PM CDT | Severe Thunderstorm Warning | ILX | Clay | 59 min |
| Jun 25, 11:54 PM CDT | Flash Flood Warning | ILX | Clay, Lawrence, Richland | 12 hr |
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, 2.5 hours before the alert went out and 107 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1094 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 8 m²/s²
- 0-3 km storm-relative helicity
- 189 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 7:36 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Bond, Calhoun, Clinton, Edwards, Fayette and 27 more | 6 hr |
| Jun 25, 10:22 PM CDT | Mesoscale Discussion | SPC | Gallatin, Hardin, Pope, Saline, Wabash, White and 1 more | 53 min |
| Jun 26, 1:21 AM CDT | Mesoscale Discussion | SPC | Alexander, Clinton, Edwards, Franklin, Gallatin, Hamilton and 20 more | 84 min |
| Jun 26, 1:58 AM CDT | Severe Thunderstorm Watch | SPC | Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 12 more | 4 hr |
| Jun 26, 4:14 AM CDT | Mesoscale Discussion | SPC | Massac | 91 min |
| Jun 26, 2:24 PM CDT | Severe Thunderstorm Watch | SPC | Monroe, Randolph | 5 hr |
| Jun 26, 6:22 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Greene, Hancock and 9 more | 83 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.