Alert archive / Missouri / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 239

May 6, 200226 counties in Illinois; Posey County, Indiana; 36 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at May 6, 2002, 10:45 AM CDT for 26 counties in Illinois; Posey County, Indiana; 36 counties in Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 6, 2002, 10:45 AM CDT (15:45 UTC)
Expired
May 6, 2002, 4:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 63 counties

Bond County, IL, Clay County, IL, Clinton County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Shelby County, IL, Union County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Posey County, IN, Bollinger County, MO, Camden County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Hickory County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Oregon County, MO, Osage County, MO, Ozark 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, Shannon County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 96 km from the middle of the area, began a volume at 15:48 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

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

IssuedProductOfficeCountiesLasted
May 6, 11:22 AM CDTFlash Flood WarningILXCrawford, Effingham, Jasper6 hr
May 6, 2:41 PM CDTFlash Flood WarningILXClay, Lawrence, Richland6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 3.8 hours before the alert went out and 259 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 2002-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 219 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 2002-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 551 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
219 J/kg
Mixed-layer CIN
-366 J/kg
Mixed-layer LCL
1173 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
551 m²/s²
0-3 km storm-relative helicity
626 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 061533
SEL9  
SPC WW 061524
ILZ000-MOZ000-062100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 239
STORM PREDICTION CENTER NORMAN OK
1024 AM CDT MON MAY 6 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   SOUTHERN AND CENTRAL ILLINOIS                           
   SOUTHERN AND EASTERN MISSOURI                           

EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 1045 AM UNTIL 400
PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 65 STATUTE MILES
EITHER SIDE OF A LINE FROM 70 MILES WEST NORTHWEST OF WEST PLAINS
MISSOURI TO 45 MILES EAST OF SALEM ILLINOIS.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 238.  WATCH NUMBER 238 WILL NOT BE
IN EFFECT AFTER 1045 AM CDT.

DISCUSSION...MO/IL MCS IS BEING FED BY PLUME OF VERY MOIST/
UNSTABLE INFLOW ASSOCIATED WITH SSWLY LOW LEVEL JET OVER OK. 
SYSTEM ALSO APPEARS TO BE SUPPORTED BY ASCENT ON SRN FRINGE OF NRN
STREAM JET IMPULSE.  ACTIVITY MAY STRENGTHEN IN THE NEXT FEW HOURS
AS SURFACE HEATING CONTINUES...AND DEEP WLY SHEAR REMAINS AOA 45
KTS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550.  MEAN STORM
MOTION VECTOR 29035.

...CORFIDI

374,0874 361,0924 380,0932 393,0883

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 7:45 AM CDTSevere Thunderstorm WatchSPCAdams, Calhoun, Greene, Jersey, Madison, Pike and 1 more4 hr
May 6, 5:30 PM CDTSevere Thunderstorm WatchSPCBoone, Carroll, Jo Daviess, McHenry, Ogle, Stephenson and 1 more6 hr
May 6, 3:30 PM CDTSevere Thunderstorm WatchSPCFloyd, Harrison6 hr
May 5, 9:00 PM CDTSevere Thunderstorm WatchSPCAdair, Andrew, Bates, Benton, Buchanan, Caldwell and 27 more5 hr
May 6, 2:00 AM CDTSevere Thunderstorm WatchSPCAdair, Boone, Caldwell, Carroll, Cass, Chariton and 20 more5 hr

Nearby

Severe Thunderstorm Watches in Missouri, 2002Severe Thunderstorm Watches in Illinois, 2002Severe Thunderstorm Watches in Indiana, 2002Every severe thunderstorm watch in 2002

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.