Alert archive / Illinois / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 561

June 26, 201141 counties in Illinois; Jefferson County, Lee County, Van Buren County, Iowa; 5 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 26, 2011, 7:12 PM CDT for 41 counties in Illinois; Jefferson County, Lee County, Van Buren County, Iowa; 5 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 26, 2011, 7:12 PM CDT (00:12 UTC)
Expired
Jun 27, 2011, 1:33 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
65 kt
All 49 counties

Jefferson County, IA, Lee County, IA, Van Buren County, IA, Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Washington County, IL, Clark County, MO, Knox County, MO, Lewis County, MO, Marion County, MO, Scotland County, MO

The radar

The Lincoln radar (KILX), 135 km from the middle of the area, began a volume at 00:12 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
70%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 26, 7:53 PM CDTSevere Thunderstorm WarningDVNLee, Van Buren67 min
Jun 26, 8:14 PM CDTFlash Flood WarningDVNJefferson, Lee, Van Buren9 hr
Jun 26, 8:30 PM CDTFlash Flood WarningLSXKnox, Lewis12 hr
Jun 26, 8:31 PM CDTSevere Thunderstorm WarningDVNHancock, Henderson59 min
Jun 26, 8:34 PM CDTSevere Thunderstorm WarningLSXAdams41 min
Jun 26, 9:16 PM CDTSevere Thunderstorm WarningLSXAdams, Brown59 min
Jun 26, 9:23 PM CDTSevere Thunderstorm WarningILXSchuyler52 min
Jun 26, 9:37 PM CDTFlash Flood WarningDVNHancock, Henderson, McDonough9 hr
Jun 26, 10:09 PM CDTSevere Thunderstorm WarningLSXBrown36 min
Jun 26, 10:11 PM CDTFlash Flood WarningILXFulton, Schuyler12 hr
Jun 26, 10:11 PM CDTFlash Flood WarningLSXAdams, Brown11 hr
Jun 26, 10:15 PM CDTSevere Thunderstorm WarningILXSchuyler30 min
Jun 26, 11:11 PM CDTSevere Thunderstorm WarningILXLogan, Mason, Peoria, Tazewell, Woodford64 min
Jun 26, 11:21 PM CDTSevere Thunderstorm WarningILXLogan, Menard, Sangamon54 min
Jun 26, 11:33 PM CDTSevere Thunderstorm WarningILXDeWitt, Logan, McLean, Tazewell, Woodford57 min
Jun 26, 11:35 PM CDTSevere Thunderstorm WarningDVNHenry, Jefferson, Van Buren, Washington55 min
Jun 27, 12:09 AM CDTSevere Thunderstorm WarningILXChristian, DeWitt, Macon, Moultrie, Piatt66 min
Jun 27, 12:11 AM CDTSevere Thunderstorm WarningLSXKnox19 min
Jun 27, 12:25 AM CDTSevere Thunderstorm WarningILXChampaign, Douglas, Edgar, Macon, Vermilion65 min
Jun 27, 12:26 AM CDTSevere Thunderstorm WarningLSXAdams49 min
Jun 27, 12:55 AM CDTTornado WarningLSXMarion, Monroe, Ralls, Shelby20 min
Jun 27, 1:02 AM CDTSevere Thunderstorm WarningDVNHancock, McDonough58 min
Jun 27, 1:08 AM CDTTornado WarningLSXAdams, Calhoun, Pike37 min
Jun 27, 1:13 AM CDTSevere Thunderstorm WarningLSXAdams, Brown62 min
Jun 27, 1:27 AM CDTSevere Thunderstorm WarningLSXCalhoun63 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

Davenport, (KDVN), launched 00:00Z, 0.2 hours before the alert went out and 176 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-pSkew-T log-p diagram, Davenport, at 00:00Z on 2011-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2011-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
15 J/kg
Mixed-layer CIN
-398 J/kg
Mixed-layer LCL
1115 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 10:02 PM CDTSevere Thunderstorm WatchSPCHancock, Henderson, McDonough, Mercer, Rock Island, Warren5 hr
Jun 27, 12:58 AM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 48 more92 min
Jun 27, 1:32 AM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 43 more7 hr
Jun 27, 3:14 AM CDTMesoscale DiscussionSPCAlexander, Bond, Champaign, Clark, Clay, Clinton and 39 more91 min
Jun 27, 5:38 AM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 35 more97 min
Jun 27, 11:30 AM CDTMesoscale DiscussionSPCHardin, Massac, Pope90 min
Jun 26, 8:48 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Calhoun, Carroll and 17 more117 min
Jun 26, 10:06 PM CDTMesoscale DiscussionSPCAdair, Andrew, Audrain, Boone, Buchanan, Caldwell and 29 more84 min
Jun 27, 3:54 PM CDTMesoscale DiscussionSPCBarry, Barton, Camden, Cedar, Christian, Dade and 21 more2 hr

Nearby

Severe Thunderstorm Watches in Illinois, 2011Severe Thunderstorm Watches in Missouri, 2011Severe Thunderstorm Watches in Iowa, 2011Every severe thunderstorm watch in 2011

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.