Alert archive / Illinois / Tornado Watches in 2002

Tornado Watch 139

April 21, 20024 states

The Storm Prediction Center issued this tornado watch at Apr 21, 2002, 2:15 PM CDT for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 21, 2002, 2:15 PM CDT (19:15 UTC)
Expired
Apr 21, 2002, 6:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
All 62 counties

Alexander County, IL, Bond County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Massac County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Shelby County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Vigo County, IN, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Hickman County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Iron County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Perry County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 109 km from the middle of the area, began a volume at 19:19 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

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

IssuedProductOfficeCountiesLasted
Apr 21, 2:22 PM CDTSevere Thunderstorm WarningILXLawrence38 min
Apr 21, 2:27 PM CDTSevere Thunderstorm WarningILXLawrence33 min
Apr 21, 2:53 PM CDTSevere Thunderstorm WarningPAHPerry52 min
Apr 21, 3:24 PM CDTSevere Thunderstorm WarningILXEffingham51 min
Apr 21, 3:28 PM CDTSevere Thunderstorm WarningPAHFranklin32 min
Apr 21, 3:36 PM CDTSevere Thunderstorm WarningPAHJefferson14 min
Apr 21, 3:40 PM CDTTornado WarningPAHFranklin35 min
Apr 21, 3:58 PM CDTSevere Thunderstorm WarningILXClay32 min
Apr 21, 4:01 PM CDTTornado WarningPAHWayne29 min
Apr 21, 4:04 PM CDTTornado WarningPAHHamilton26 min
Apr 21, 4:07 PM CDTSevere Thunderstorm WarningPAHJackson23 min
Apr 21, 4:26 PM CDTSevere Thunderstorm WarningPAHFranklin34 min
Apr 21, 4:28 PM CDTSevere Thunderstorm WarningPAHCape Girardeau32 min
Apr 21, 4:29 PM CDTTornado WarningPAHWhite31 min
Apr 21, 4:47 PM CDTSevere Thunderstorm WarningPAHHamilton, Saline28 min
Apr 21, 4:50 PM CDTSevere Thunderstorm WarningPAHUnion40 min
Apr 21, 5:07 PM CDTSevere Thunderstorm WarningPAHGallatin, White23 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.3 hours before the alert went out and 289 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 2002-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 2002-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 504 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
1 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
417 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
504 m²/s²
0-3 km storm-relative helicity
540 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 211913
SEL9  
SPC WW 211908
ILZ000-MOZ000-212300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 139
STORM PREDICTION CENTER NORMAN OK
208 PM CDT SUN APR 21 2002

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   SOUTHERN ILLINOIS                           
   SOUTHEASTERN MISSOURI                           

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 215 PM UNTIL 600
PM CDT.

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

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 30 MILES SOUTHEAST OF POPLAR BLUFF MISSOURI TO 15
MILES WEST NORTHWEST OF MATTOON ILLINOIS.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES SEVERE
THUNDERSTORM WATCH NUMBER 136.  WATCH NUMBER 136 WILL NOT BE IN
EFFECT AFTER 215 PM CDT.  CONTINUE...WW 137...WW 138...

DISCUSSION...INCREASING TORNADO THREAT DEVELOPING NEAR AND NORTH OF
OUTFLOW BOUNDARY ACROSS CENTRAL IL...WHERE SURFACE LOW WILL LIKELY
TRACK.  SUPERCELLS WILL ALSO LIKELY DEVELOP SWD ALONG APPROACHING
COLD FRONT INTO SRN IL.


AVIATION...TORNADOES AND 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 500. 
MEAN STORM MOTION VECTOR 26040.


...EVANS

362,0912 393,0895 393,0871 362,0884

WWUS20 KWNS 211913
SEL9  
SPC WW 211908
ILZ000-MOZ000-212300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 139
STORM PREDICTION CENTER NORMAN OK
208 PM CDT SUN APR 21 2002

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   SOUTHERN ILLINOIS                           
   SOUTHEASTERN MISSOURI                           

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 215 PM UNTIL 600
PM CDT.

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

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 30 MILES SOUTHEAST OF POPLAR BLUFF MISSOURI TO 15
MILES WEST NORTHWEST OF MATTOON ILLINOIS.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES SEVERE
THUNDERSTORM WATCH NUMBER 136.  WATCH NUMBER 136 WILL NOT BE IN
EFFECT AFTER 215 PM CDT.  CONTINUE...WW 137...WW 138...

DISCUSSION...INCREASING TORNADO THREAT DEVELOPING NEAR AND NORTH OF
OUTFLOW BOUNDARY ACROSS CENTRAL IL...WHERE SURFACE LOW WILL LIKELY
TRACK.  SUPERCELLS WILL ALSO LIKELY DEVELOP SWD ALONG APPROACHING
COLD FRONT INTO SRN IL.


AVIATION...TORNADOES AND 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 500. 
MEAN STORM MOTION VECTOR 26040.


...EVANS

362,0912 393,0895 393,0871 362,0884

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 5:30 AM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Clinton, Fayette, Greene, Jackson and 9 more6 hr
Apr 21, 11:00 AM CDTSevere Thunderstorm WatchSPCAlexander, Bond, Calhoun, Clay, Clinton, Crawford and 30 more5 hr
Apr 21, 12:45 PM CDTSevere Thunderstorm WatchSPCHardin5 hr
Apr 21, 5:30 PM CDTSevere Thunderstorm WatchSPCGallatin, Hardin, Johnson, Pope5 hr
Apr 21, 1:30 PM CDTSevere Thunderstorm WatchSPCBoyd, Breathitt, Carter, Elliott, Floyd, Greenup and 8 more5 hr
Apr 21, 2:00 AM CDTSevere Thunderstorm WatchSPCAdair, Andrew, Atchison, Bates, Benton, Buchanan and 38 more6 hr

Nearby

Tornado Watches in Illinois, 2002Tornado Watches in Missouri, 2002Tornado Watches in Kentucky, 2002Every tornado 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.