Alert archive / Illinois / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 350
The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2017, 2:34 AM CDT for 4 states. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 18, 2017, 2:34 AM CDT (07:34 UTC)
- Expired
- Jun 18, 2017, 5:45 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 54 counties
Alexander County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Crawford County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Jackson County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Ballard County, KY, Caldwell County, KY, Crittenden County, KY, Daviess County, KY, Hancock County, KY, Henderson County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, McCracken County, KY, McLean County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Cape Girardeau County, MO, Perry County, MO, Scott County, MO
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 40%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 3:19 AM CDT | Severe Thunderstorm Warning | PAH | Edwards, Wayne | 27 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, 7.6 hours before the alert went out and 253 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
- 606 J/kg
- Mixed-layer CIN
- -96 J/kg
- Mixed-layer LCL
- 1403 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 71 m²/s²
- 0-3 km storm-relative helicity
- 134 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 5.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 17, 8:17 PM CDT | Mesoscale Discussion | SPC | Adams, Boone, Brown, Bureau, Cass, Champaign and 52 more | 58 min |
| Jun 17, 9:50 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Champaign, Christian, Clark, Clay and 32 more | 55 min |
| Jun 17, 10:53 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Christian, Clay, Clinton, Coles and 22 more | 6 hr |
| Jun 18, 1:40 AM CDT | Mesoscale Discussion | SPC | Bond, Clay, Clinton, Crawford, Cumberland, Edwards and 18 more | 3 hr |
| Jun 18, 4:48 AM CDT | Mesoscale Discussion | SPC | Gallatin, Hardin, Johnson, Massac, Pope, Pulaski | 117 min |
| Jun 17, 8:23 PM CDT | Mesoscale Discussion | SPC | Bates, Benton, Boone, Buchanan, Caldwell, Carroll and 26 more | 2 hr |
| Jun 17, 9:34 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Boone, Camden, Carroll and 29 more | 116 min |
| Jun 17, 10:18 PM CDT | Severe Thunderstorm Watch | SPC | Barton, Benton, Camden, Cedar, Hickory, Jasper and 4 more | 6 hr |
| Jun 17, 11:55 PM CDT | Mesoscale Discussion | SPC | Barton, Cedar, Dade, Jasper, Lawrence, McDonald and 3 more | 95 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2017Severe Thunderstorm Watches in Indiana, 2017Severe Thunderstorm Watches in Kentucky, 2017Every severe thunderstorm watch in 2017
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.