Alert archive / Illinois / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 235
The Storm Prediction Center issued this severe thunderstorm watch at May 3, 2012, 11:34 PM CDT for 31 counties in Illinois. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- May 3, 2012, 11:34 PM CDT (04:34 UTC)
- Expired
- May 4, 2012, 5:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 31 counties
Bureau County, IL, Cass County, IL, Champaign County, IL, DeWitt County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Kankakee County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Schuyler County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Warren County, IL, Woodford County, IL
The radar
The Lincoln radar (KILX), 72 km from the middle of the area, began a volume at 04:36 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
- 50%
- 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
9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 12:07 AM CDT | Severe Thunderstorm Warning | ILX | Peoria, Tazewell, Woodford | 53 min |
| May 4, 12:26 AM CDT | Flash Flood Warning | DVN | Bureau, Putnam | 6 hr |
| May 4, 12:29 AM CDT | Severe Thunderstorm Warning | ILX | Marshall, Peoria | 46 min |
| May 4, 12:34 AM CDT | Severe Thunderstorm Warning | LOT | Grundy, LaSalle, Livingston | 71 min |
| May 4, 12:46 AM CDT | Flash Flood Warning | LOT | LaSalle, Livingston | 6 hr |
| May 4, 12:52 AM CDT | Severe Thunderstorm Warning | ILX | McLean, Woodford | 35 min |
| May 4, 1:26 AM CDT | Severe Thunderstorm Warning | LOT | Ford, Grundy, Iroquois, Kankakee, Livingston | 63 min |
| May 4, 2:29 AM CDT | Flash Flood Warning | ILX | Marshall | 6 hr |
| May 4, 3:07 AM CDT | Severe Thunderstorm Warning | DVN | Hancock, Henderson | 38 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, 4.6 hours before the alert went out and 112 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
- 1905 J/kg
- Mixed-layer CIN
- -30 J/kg
- Mixed-layer LCL
- 1071 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 3, 7:09 PM CDT | Tornado Watch | SPC | Adams, Brown, Pike, Rock Island | 6 hr |
| May 3, 10:29 PM CDT | Mesoscale Discussion | SPC | Cook, DeKalb, DuPage, Ford, Grundy, Iroquois and 7 more | 61 min |
| May 3, 11:18 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, DeWitt, Fulton and 22 more | 27 min |
| May 4, 12:53 AM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown | 4 hr |
| May 4, 2:16 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, DeWitt, Ford and 25 more | 119 min |
| May 4, 11:36 AM CDT | Mesoscale Discussion | SPC | Clay, Clinton, Edwards, Franklin, Gallatin, Hamilton and 17 more | 84 min |
| May 4, 1:29 PM CDT | Severe Thunderstorm Watch | SPC | Edwards, Wabash, White | 5 hr |
Nearby
Severe Thunderstorm Watches in Illinois, 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.