Alert archive / Missouri / Severe Thunderstorm Watches in 2003

Severe Thunderstorm Watch 757

July 18, 200312 counties in Illinois; Ballard County, Kentucky; 38 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jul 18, 2003, 6:50 AM CDT for 12 counties in Illinois; Ballard County, Kentucky; 38 counties in Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 18, 2003, 6:50 AM CDT (11:50 UTC)
Expired
Jul 18, 2003, 12:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 51 counties

Alexander County, IL, Franklin County, IL, Jackson County, IL, Johnson County, IL, Monroe County, IL, Perry County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Williamson County, IL, Ballard County, KY, Audrain County, MO, Bollinger County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Mississippi County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, New Madrid County, MO, Osage County, MO, Perry County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Warren County, MO, Washington County, MO, Wayne County, MO

The radar

The St Louis radar (KLSX), 52 km from the middle of the area, began a volume at 11:51 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

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

IssuedProductOfficeCountiesLasted
Jul 18, 9:14 AM CDTSevere Thunderstorm WarningLSXSaint Charles, Saint Louis, City of Saint Louis46 min
Jul 18, 9:41 AM CDTSevere Thunderstorm WarningLSXMonroe, Saint Clair49 min
Jul 18, 10:23 AM CDTSevere Thunderstorm WarningPAHPerry52 min
Jul 18, 10:58 AM CDTSevere Thunderstorm WarningPAHJackson62 min
Jul 18, 11:16 AM CDTSevere Thunderstorm WarningPAHUnion44 min
Jul 18, 11:31 AM CDTSevere Thunderstorm WarningPAHCape Girardeau44 min
Jul 18, 11:48 AM CDTSevere Thunderstorm WarningPAHAlexander, Johnson, Pulaski27 min
Jul 18, 11:59 AM CDTSevere Thunderstorm WarningPAHUnion16 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, 11.8 hours before the alert went out and 292 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 00:00Z on 2003-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2256 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 00:00Z on 2003-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 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
2256 J/kg
Mixed-layer CIN
-134 J/kg
Mixed-layer LCL
1630 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 9:40 PM CDTSevere Thunderstorm WatchSPCBureau, Champaign, DeWitt, Ford, Grundy, Henry and 13 more5 hr
Jul 17, 11:41 PM CDTMesoscale DiscussionSPCBureau, Champaign, Ford, Grundy, Henry, Iroquois and 12 more94 min
Jul 18, 2:01 AM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, Cumberland, DeWitt, Douglas and 13 more59 min
Jul 18, 2:26 AM CDTMesoscale DiscussionSPCHenderson, Knox, Mercer, Rock Island, Warren3 hr
Jul 18, 4:30 AM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 38 more6 hr
Jul 18, 6:15 AM CDTMesoscale DiscussionSPCAdams, Alexander, Bond, Brown, Calhoun, Clinton and 18 more60 min
Jul 18, 9:06 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Franklin, Greene and 16 more84 min
Jul 18, 9:55 AM CDTSevere Thunderstorm WatchSPCAlexander, Clinton, Franklin, Gallatin, Hamilton, Hardin and 15 more5 hr
Jul 18, 3:23 PM CDTMesoscale DiscussionSPCAdams, Calhoun, Jersey, Monroe, Pike, Randolph97 min
Jul 18, 3:45 PM CDTSevere Thunderstorm WatchSPCCalhoun, Greene, Jersey, Monroe5 hr
Jul 18, 12:45 PM CDTMesoscale DiscussionSPCBallard, Calloway, Carlisle, Fulton, Graves, Hickman and 3 more60 min

Nearby

Severe Thunderstorm Watches in Missouri, 2003Severe Thunderstorm Watches in Illinois, 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.