Alert archive / Illinois / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 549
The Storm Prediction Center issued this severe thunderstorm watch at Jun 25, 2011, 1:06 PM CDT for 26 counties in Illinois; 9 counties in Kentucky; 24 counties in Missouri. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 25, 2011, 1:06 PM CDT (18:06 UTC)
- Expired
- Jun 25, 2011, 4:06 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 59 counties
Alexander County, IL, Bond County, IL, Clinton County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Madison County, IL, Marion County, IL, Massac County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Marshall County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Perry County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Warren County, MO, Washington County, MO, Wayne County, MO
The radar
The St Louis radar (KLSX), 99 km from the middle of the area, began a volume at 18:09 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
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 2:03 PM CDT | Severe Thunderstorm Warning | LSX | Randolph | 20 min |
| Jun 25, 2:06 PM CDT | Severe Thunderstorm Warning | PAH | Perry | 31 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, 6.1 hours before the alert went out and 284 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
- 1082 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- -39 m²/s²
- 0-3 km storm-relative helicity
- 95 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 3:51 AM CDT | Mesoscale Discussion | SPC | Calhoun, Jersey, Madison, Monroe, Randolph, Saint Clair | 84 min |
| Jun 25, 11:17 AM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Calhoun, Christian, Clark, Clay and 43 more | 118 min |
| Jun 25, 2:59 PM CDT | Mesoscale Discussion | SPC | Alexander, Clinton, Franklin, Gallatin, Hamilton, Hardin and 16 more | 91 min |
| Jun 25, 1:46 AM CDT | Mesoscale Discussion | SPC | Atchison, Holt | 89 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2011Severe Thunderstorm Watches in Missouri, 2011Severe Thunderstorm Watches in Kentucky, 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.