Alert archive / Illinois / Tornado Watches in 2008

Tornado Watch 479

June 7, 200832 counties in Illinois; 9 counties in Iowa

The Storm Prediction Center issued this tornado watch at Jun 7, 2008, 2:01 PM CDT for 32 counties in Illinois; 9 counties in Iowa. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 7, 2008, 2:01 PM CDT (19:01 UTC)
Expired
Jun 7, 2008, 7:46 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 41 counties

Cedar County, IA, Clinton County, IA, Des Moines County, IA, Dubuque County, IA, Jackson County, IA, Jones County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, McHenry County, IL, Mercer County, IL, Ogle County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL

The radar

The Quad Cities radar (KDVN), 64 km from the middle of the area, began a volume at 19:02 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 7, 2:25 PM CDTSevere Thunderstorm WarningDVNRock Island, Whiteside47 min
Jun 7, 2:28 PM CDTFlash Flood WarningDVNMercer, Rock Island93 min
Jun 7, 2:52 PM CDTSevere Thunderstorm WarningDVNCarroll, Jo Daviess, Stephenson, Whiteside53 min
Jun 7, 3:10 PM CDTSevere Thunderstorm WarningLOTLee, Ogle65 min
Jun 7, 3:25 PM CDTSevere Thunderstorm WarningDVNJo Daviess, Stephenson50 min
Jun 7, 3:35 PM CDTTornado WarningILXMarshall25 min
Jun 7, 3:38 PM CDTTornado WarningLOTLaSalle, Livingston41 min
Jun 7, 3:48 PM CDTTornado WarningLOTLaSalle, Livingston57 min
Jun 7, 3:57 PM CDTSevere Thunderstorm WarningLOTWinnebago31 min
Jun 7, 4:28 PM CDTTornado WarningLOTGrundy, Livingston47 min
Jun 7, 5:07 PM CDTSevere Thunderstorm WarningLOTCook, Lake32 min
Jun 7, 5:21 PM CDTTornado WarningLOTCook, Will54 min
Jun 7, 5:45 PM CDTTornado WarningLOTKankakee, Will60 min
Jun 7, 6:08 PM CDTTornado WarningLOTCook, Will67 min
Jun 7, 6:32 PM CDTTornado WarningLOTCook50 min
Jun 7, 6:36 PM CDTSevere Thunderstorm WarningLOTCook, DuPage24 min
Jun 7, 7:27 PM CDTSevere Thunderstorm WarningLOTLake33 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 12:00Z, 7.0 hours before the alert went out and 58 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 12:00Z on 2008-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2173 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 12:00Z on 2008-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 173 square meters per square second.19395878Sfc1 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
2173 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
173 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 7, 2:31 AM CDTMesoscale DiscussionSPCClark, Coles, Crawford, Cumberland, Douglas, Edgar and 4 more119 min
Jun 7, 10:35 AM CDTMesoscale DiscussionSPCCarroll, Jo Daviess, Rock Island, Stephenson, Whiteside85 min
Jun 7, 1:50 PM CDTMesoscale DiscussionSPCCarroll, Henderson, Henry, Jo Daviess, Mercer, Ogle and 5 more55 min
Jun 7, 6:34 PM CDTMesoscale DiscussionSPCBoone, Cook, DeKalb, DuPage, Jo Daviess, Kane and 5 more56 min
Jun 7, 12:10 PM CDTMesoscale DiscussionSPCBoone, Buena Vista, Calhoun, Carroll, Cherokee, Clay and 16 more95 min
Jun 7, 12:17 PM CDTTornado WatchSPCAllamakee, Audubon, Benton, Black Hawk, Boone, Bremer and 37 more8 hr
Jun 7, 3:29 PM CDTMesoscale DiscussionSPCAdams, Audubon, Cass, Fremont, Harrison, Mills and 4 more3 hr
Jun 7, 4:25 PM CDTTornado WatchSPCBuena Vista, Cherokee, Clay, Fremont, Harrison, Ida and 7 more7 hr
Jun 7, 1:35 PM CDTMesoscale DiscussionSPCCalumet, Columbia, Dane, Dodge, Fond du Lac, Grant and 16 more85 min

Nearby

Tornado Watches in Illinois, 2008Tornado Watches in Iowa, 2008Every tornado watch in 2008

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.