Alert archive / Illinois / Severe Thunderstorm Watches in 2003

Severe Thunderstorm Watch 827

August 1, 200319 counties in Illinois; 4 counties in Kentucky; 16 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Aug 1, 2003, 3:20 PM CDT for 19 counties in Illinois; 4 counties in Kentucky; 16 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 1, 2003, 3:20 PM CDT (20:20 UTC)
Expired
Aug 1, 2003, 9:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 39 counties

Alexander 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, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saline County, IL, Union County, IL, Washington County, IL, Wayne County, IL, Williamson County, IL, Ballard County, KY, Carlisle County, KY, Livingston County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Iron County, MO, Madison County, MO, Mississippi County, MO, Perry County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Washington County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 124 km from the middle of the area, began a volume at 20:19 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 1, 3:49 PM CDTFlash Flood WarningLSXJefferson, Sainte Genevieve, Saint Francois5 hr
Aug 1, 4:56 PM CDTSevere Thunderstorm WarningLSXMadison, Saint Francois49 min
Aug 1, 5:06 PM CDTTornado WarningLSXMadison, Saint Francois39 min
Aug 1, 5:23 PM CDTSevere Thunderstorm WarningLSXIron22 min
Aug 1, 5:44 PM CDTSevere Thunderstorm WarningLSXIron46 min
Aug 1, 5:45 PM CDTSevere Thunderstorm WarningLSXMadison45 min
Aug 1, 6:28 PM CDTSevere Thunderstorm WarningLSXMadison62 min
Aug 1, 6:33 PM CDTSevere Thunderstorm WarningLSXIron, Reynolds42 min
Aug 1, 7:15 PM CDTSevere Thunderstorm WarningPAHWayne60 min
Aug 1, 7:21 PM CDTSevere Thunderstorm WarningLSXIron39 min
Aug 1, 8:10 PM CDTFlash Flood WarningLSXIron, Madison, Reynolds5 hr

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, 8.3 hours before the alert went out and 300 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, Lincoln, IL at 12:00Z on 2003-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1369 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, Lincoln, IL at 12:00Z on 2003-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 138 square meters per square second.193958Sfc1 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
1369 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1402 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
138 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 31, 8:19 PM CDTMesoscale DiscussionSPCBoone, Carroll, Jo Daviess, Ogle, Stephenson, Winnebago116 min
Aug 1, 10:59 AM CDTMesoscale DiscussionSPCBureau, DeKalb, Ford, Fulton, Grundy, Henderson and 20 more2 hr
Aug 1, 2:00 PM CDTSevere Thunderstorm WatchSPCAdams, Boone, Brown, Bureau, Cass, DeKalb and 35 more6 hr
Aug 1, 2:58 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 13 more2 hr
Aug 1, 5:49 PM CDTMesoscale DiscussionSPCBoone, Brown, Bureau, Cass, DeKalb, Fulton and 29 more86 min
Jul 31, 7:12 PM CDTMesoscale DiscussionSPCBarton, Cedar, Christian, Dade, Dallas, Douglas and 14 more93 min
Aug 1, 10:35 AM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Camden, Cass and 35 more2 hr
Aug 1, 2:20 PM CDTSevere Thunderstorm WatchSPCBarry, Barton, Camden, Cedar, Christian, Dade and 21 more6 hr
Aug 1, 6:08 PM CDTMesoscale DiscussionSPCBarry, Barton, Cedar, Christian, Dade, Dallas and 13 more2 hr

Nearby

Severe Thunderstorm Watches in Illinois, 2003Severe Thunderstorm Watches in Missouri, 2003Severe Thunderstorm Watches in Kentucky, 2003Every severe thunderstorm watch in 2003

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.