Alert archive / Illinois / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 321

June 2, 200960 counties in Illinois; Gibson County, Posey County, Vanderburgh County, Indiana; 32 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 2, 2009, 12:27 PM CDT for 60 counties in Illinois; Gibson County, Posey County, Vanderburgh County, Indiana; 32 counties in Missouri. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Jun 2, 2009, 12:27 PM CDT (17:27 UTC)
Expired: Jun 2, 2009, 8:00 PM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 95 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Lawrence County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Pike County, IL, Pope County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Union County, IL, Vermilion County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Gibson County, IN, Posey County, IN, Vanderburgh County, IN, Audrain County, MO, Bollinger County, MO, Boone County, MO, Callaway County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Madison County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Perry County, MO, Pike County, MO, Ralls County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shelby County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 86 km from the middle of the area, began a volume at 17:30 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: 10%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 40%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 10%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jun 2, 1:02 PM CDT	Severe Thunderstorm Warning	LSX	Madison, Saint Clair	43 min
Jun 2, 1:17 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	43 min
Jun 2, 1:35 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis	40 min
Jun 2, 1:44 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Warren	31 min
Jun 2, 1:54 PM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Saint Louis	51 min
Jun 2, 2:09 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	29 min
Jun 2, 2:19 PM CDT	Severe Thunderstorm Warning	LSX	Madison, Monroe, Saint Clair	41 min
Jun 2, 3:14 PM CDT	Severe Thunderstorm Warning	LSX	Adams	46 min
Jun 2, 3:29 PM CDT	Severe Thunderstorm Warning	LSX	Macoupin, Montgomery	31 min
Jun 2, 3:52 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Fayette, Marion	38 min
Jun 2, 3:55 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Douglas, Moultrie, Piatt	50 min
Jun 2, 3:58 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	47 min
Jun 2, 4:01 PM CDT	Flash Flood Warning	LSX	Lewis, Marion, Shelby	3 hr
Jun 2, 4:14 PM CDT	Tornado Warning	LSX	Adams, Brown	31 min
Jun 2, 4:25 PM CDT	Severe Thunderstorm Warning	LSX	Fayette, Marion	50 min
Jun 2, 4:44 PM CDT	Severe Thunderstorm Warning	ILX	Cass, Morgan, Schuyler	48 min
Jun 2, 4:44 PM CDT	Tornado Warning	LSX	Brown	46 min
Jun 2, 6:11 PM CDT	Severe Thunderstorm Warning	ILX	Lawrence	17 min
Jun 2, 7:18 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	57 min
Jun 2, 7:54 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Jersey, Madison	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, 5.5 hours before the alert went out and 155 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1021 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 125 m²/s²
0-3 km storm-relative helicity: 164 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 1, 8:57 PM CDT	Mesoscale Discussion	SPC	Champaign, DeWitt, Ford, Fulton, Iroquois, McDonough and 6 more	63 min
Jun 2, 11:58 AM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Christian, Clark, Clay, Clinton and 40 more	92 min
Jun 2, 3:47 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 34 more	88 min
Jun 2, 6:22 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 32 more	83 min
Jun 2, 2:18 PM CDT	Severe Thunderstorm Watch	SPC	Bartholomew, Boone, Brown, Clark, Clay, Daviess and 41 more	8 hr
Jun 2, 6:13 PM CDT	Mesoscale Discussion	SPC	Bartholomew, Brown, Clark, Clay, Crawford, Daviess and 30 more	62 min
Jun 1, 9:27 PM CDT	Mesoscale Discussion	SPC	Atchison, Gentry, Harrison, Holt, Mercer, Nodaway and 2 more	63 min
Jun 2, 2:14 PM CDT	Mesoscale Discussion	SPC	Bates, Benton, Carroll, Cass, Chariton, Clay and 15 more	2 hr

Nearby

Severe Thunderstorm Watches in Illinois, 2009 Severe Thunderstorm Watches in Missouri, 2009 Severe Thunderstorm Watches in Indiana, 2009 Every severe thunderstorm watch in 2009

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.