Alert archive / Missouri / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 495

June 18, 200418 counties in Illinois; 41 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2004, 1:40 PM CDT for 18 counties in Illinois; 41 counties in Missouri. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jun 18, 2004, 1:40 PM CDT (18:40 UTC)
Expired
Jun 18, 2004, 9:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
All 59 counties

Alexander County, IL, Bond County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jackson County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Washington County, IL, Audrain County, MO, Bollinger County, MO, Butler County, MO, Callaway County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Montgomery County, MO, New Madrid County, MO, Oregon County, MO, Osage County, MO, Ozark County, MO, Perry County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Wayne County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 120 km from the middle of the area, began a volume at 18:41 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

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

IssuedProductOfficeCountiesLasted
Jun 18, 2:00 PM CDTTornado WarningLSXSaint Charles45 min
Jun 18, 2:23 PM CDTTornado WarningLSXSaint Louis52 min
Jun 18, 2:28 PM CDTSevere Thunderstorm WarningLSXWashington47 min
Jun 18, 2:45 PM CDTTornado WarningLSXJefferson, Saint Louis45 min
Jun 18, 2:52 PM CDTSevere Thunderstorm WarningLSXSaint Francois38 min
Jun 18, 3:19 PM CDTTornado WarningLSXMonroe, Saint Clair41 min
Jun 18, 3:31 PM CDTSevere Thunderstorm WarningLSXIron, Madison44 min
Jun 18, 3:35 PM CDTFlash Flood WarningLSXJefferson, Saint Louis4 hr
Jun 18, 3:36 PM CDTSevere Thunderstorm WarningLSXSainte Genevieve39 min
Jun 18, 4:11 PM CDTSevere Thunderstorm WarningLSXRandolph, Saint Clair49 min
Jun 18, 4:38 PM CDTSevere Thunderstorm WarningPAHPerry37 min
Jun 18, 5:07 PM CDTSevere Thunderstorm WarningPAHPerry53 min
Jun 18, 5:12 PM CDTSevere Thunderstorm WarningPAHWayne33 min
Jun 18, 5:25 PM CDTSevere Thunderstorm WarningLSXClinton50 min
Jun 18, 5:40 PM CDTFlash Flood WarningPAHPerry3 hr
Jun 18, 5:43 PM CDTSevere Thunderstorm WarningPAHUnion62 min
Jun 18, 5:46 PM CDTSevere Thunderstorm WarningLSXMarion44 min
Jun 18, 6:01 PM CDTFlash Flood WarningPAHPerry3 hr
Jun 18, 6:44 PM CDTSevere Thunderstorm WarningPAHUnion31 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

Springfield, MO (KSGF), launched 12:00Z, 6.7 hours before the alert went out and 252 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, Springfield, MO at 12:00Z on 2004-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 686 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, Springfield, MO at 12:00Z on 2004-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 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
686 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
1042 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 18, 1:20 PM CDTMesoscale DiscussionSPCBond, Brown, Calhoun, Cass, Christian, Clinton and 27 more115 min
Jun 18, 3:49 PM CDTMesoscale DiscussionSPCClay, Crawford, Edwards, Effingham, Franklin, Gallatin and 15 more116 min
Jun 18, 6:17 PM CDTMesoscale DiscussionSPCBond, Clark, Clay, Crawford, Cumberland, Edwards and 22 more88 min
Jun 18, 10:49 AM CDTMesoscale DiscussionSPCMcDonald116 min

Nearby

Severe Thunderstorm Watches in Missouri, 2004Severe Thunderstorm Watches in Illinois, 2004Every severe thunderstorm watch in 2004

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.