Alert archive / Illinois / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 349

June 17, 201728 counties in Illinois; 17 counties in Indiana; 18 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 17, 2017, 10:53 PM CDT for 28 counties in Illinois; 17 counties in Indiana; 18 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 17, 2017, 10:53 PM CDT (03:53 UTC)
Expired: Jun 18, 2017, 4:32 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 63 counties

Bond County, IL, Calhoun County, IL, Christian County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jasper County, IL, Jersey County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Pike County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Shelby County, IL, Washington County, IL, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Fountain County, IN, Grant County, IN, Hamilton County, IN, Howard County, IN, Madison County, IN, Miami County, IN, Montgomery County, IN, Parke County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Wabash County, IN, Warren County, IN, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Lincoln County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO

The radar

The Lincoln radar (KILX), 73 km from the middle of the area, began a volume at 03:57 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: 40%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 10%
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
Jun 17, 10:56 PM CDT	Severe Thunderstorm Warning	IND	Fountain, Montgomery, Tippecanoe, Warren	49 min
Jun 17, 11:04 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Boone, Callaway, Cole, Moniteau	56 min
Jun 17, 11:42 PM CDT	Severe Thunderstorm Warning	IND	Boone, Clinton, Hamilton, Tipton	33 min
Jun 17, 11:47 PM CDT	Flash Flood Warning	ILX	Christian, Sangamon	3 hr
Jun 17, 11:55 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Franklin, Gasconade, Montgomery, Osage, Warren	50 min
Jun 18, 12:39 AM CDT	Severe Thunderstorm Warning	IWX	Adams, Blackford, Grant, Huntington, Jay, Wells	51 min
Jun 18, 2:08 AM CDT	Severe Thunderstorm Warning	LSX	Randolph, Saint Clair, Washington	37 min
Jun 18, 3:03 AM CDT	Severe Thunderstorm Warning	ILX	Clay, Effingham, Jasper, Richland	42 min
Jun 18, 3:30 AM CDT	Severe Thunderstorm Warning	ILX	Crawford, Jasper, Lawrence, Richland	45 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, 3.9 hours before the alert went out and 110 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

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

Open this sounding in Storm Lab

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 18, 1:40 AM CDT	Mesoscale Discussion	SPC	Bond, Clay, Clinton, Crawford, Cumberland, Edwards and 18 more	3 hr
Jun 18, 2:34 AM CDT	Severe Thunderstorm Watch	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 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, 2017 Severe Thunderstorm Watches in Missouri, 2017 Severe Thunderstorm Watches in Indiana, 2017 Every 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; radar from the NEXRAD Level II archive.