Alert archive / Illinois / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 543
The Storm Prediction Center issued this severe thunderstorm watch at Jul 31, 2012, 1:13 PM CDT for 25 counties in Illinois; 22 counties in Indiana. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 31, 2012, 1:13 PM CDT (18:13 UTC)
- Expired
- Jul 31, 2012, 7:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 47 counties
Champaign 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, Ford County, IL, Iroquois County, IL, Jasper County, IL, Lawrence County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, McLean County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Benton County, IN, Brown County, IN, Clay County, IN, Daviess County, IN, Fountain County, IN, Greene County, IN, Hendricks County, IN, Jackson County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Sullivan County, IN, Tippecanoe County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN
The radar
The Lincoln radar (KILX), 110 km from the middle of the area, began a volume at 18:16 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
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 2:23 PM CDT | Severe Thunderstorm Warning | LOT | Ford | 22 min |
| Jul 31, 3:35 PM CDT | Severe Thunderstorm Warning | IND | Daviess, Greene, Lawrence, Martin, Monroe, Owen | 40 min |
| Jul 31, 4:14 PM CDT | Severe Thunderstorm Warning | IND | Daviess, Greene, Martin | 31 min |
| Jul 31, 4:50 PM CDT | Severe Thunderstorm Warning | IND | Daviess | 25 min |
| Jul 31, 5:13 PM CDT | Severe Thunderstorm Warning | IND | Daviess, Knox | 32 min |
| Jul 31, 5:45 PM CDT | Severe Thunderstorm Warning | IND | Daviess, Knox | 16 min |
| Jul 31, 6:10 PM CDT | Severe Thunderstorm Warning | IND | Bartholomew, Brown, Johnson, Shelby | 50 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, 6.2 hours before the alert went out and 50 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
- 2241 J/kg
- Mixed-layer CIN
- -70 J/kg
- Mixed-layer LCL
- 958 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 69 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.9
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 12:39 AM CDT | Mesoscale Discussion | SPC | Lake, McHenry | 96 min |
| Jul 31, 12:11 PM CDT | Mesoscale Discussion | SPC | Champaign, Clark, Clay, Coles, Crawford, Cumberland and 16 more | 64 min |
| Jul 31, 3:35 PM CDT | Mesoscale Discussion | SPC | Champaign, Clark, Clay, Coles, Crawford, Cumberland and 16 more | 55 min |
| Jul 31, 6:42 PM CDT | Mesoscale Discussion | SPC | Crawford, Edwards, Jasper, Lawrence, Richland, Wabash and 1 more | 33 min |
| Jul 31, 4:10 PM CDT | Mesoscale Discussion | SPC | Clark, Crawford, Dubois, Floyd, Gibson, Harrison and 7 more | 65 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2012Severe Thunderstorm Watches in Indiana, 2012Every severe thunderstorm watch in 2012
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.