Alert archive / Illinois / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 263

May 8, 200218 counties in Illinois

The Storm Prediction Center issued this severe thunderstorm watch at May 8, 2002, 11:30 PM CDT for 18 counties in Illinois. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 8, 2002, 11:30 PM CDT (04:30 UTC)
Expired
May 9, 2002, 4:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Champaign County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Ford County, IL, Iroquois County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, McLean County, IL, Menard County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Sangamon County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 9, 12:02 AM CDTSevere Thunderstorm WarningILXWoodford43 min
May 9, 12:17 AM CDTFlash Flood WarningILXMarshall, Peoria, Tazewell, Woodford6 hr
May 9, 12:23 AM CDTSevere Thunderstorm WarningILXChristian, Macon, Shelby52 min
May 9, 2:04 AM CDTSevere Thunderstorm WarningILXMoultrie26 min
May 9, 2:27 AM CDTSevere Thunderstorm WarningILXChampaign, Coles, Douglas63 min
May 9, 2:52 AM CDTSevere Thunderstorm WarningILXVermilion53 min
May 9, 3:14 AM CDTSevere Thunderstorm WarningILXClark, Crawford, Edgar, Jasper61 min

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 4.5 hours before the alert went out and 46 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 2002-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1076 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 2002-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 175 square meters per square second.1939587897Sfc1 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
1076 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
1020 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
175 m²/s²
0-3 km storm-relative helicity
229 m²/s²
Significant tornado parameter
1.2
Supercell composite
9.2

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 090412
SEL3  
SPC WW 090409
ILZ000-090900-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 263
STORM PREDICTION CENTER NORMAN OK
1109 PM CDT WED MAY 8 2002

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

   EAST CENTRAL ILLINOIS                           

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1130 PM
UNTIL 400 AM 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 50 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF PEORIA
ILLINOIS TO 10 MILES NORTH OF DANVILLE 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...  CONTINUE...WW 259...WW 260...WW
261...WW 262...

DISCUSSION...BOW ECHO NEAR SPI WILL LIKELY CONTINUE TRACKING EAST-
NORTHEASTWARD AROUND 40 KNOTS...WITH ISOLATED CELLS DEVELOPING
AHEAD OF FEATURE.  DAMAGING WINDS WILL REMAIN LIKELY WITH APEX OF
BOW FOR A FEW MORE HOURS.

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 500.  MEAN STORM
MOTION VECTOR 24035.

...HART

405,0895 410,0873 393,0873 393,0895

WWUS20 KWNS 090412
SEL3  
SPC WW 090409
ILZ000-090900-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 263
STORM PREDICTION CENTER NORMAN OK
1109 PM CDT WED MAY 8 2002

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

   EAST CENTRAL ILLINOIS                           

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1130 PM
UNTIL 400 AM 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 50 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF PEORIA
ILLINOIS TO 10 MILES NORTH OF DANVILLE 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...  CONTINUE...WW 259...WW 260...WW
261...WW 262...

DISCUSSION...BOW ECHO NEAR SPI WILL LIKELY CONTINUE TRACKING EAST-
NORTHEASTWARD AROUND 40 KNOTS...WITH ISOLATED CELLS DEVELOPING
AHEAD OF FEATURE.  DAMAGING WINDS WILL REMAIN LIKELY WITH APEX OF
BOW FOR A FEW MORE HOURS.

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 500.  MEAN STORM
MOTION VECTOR 24035.

...HART

405,0895 410,0873 393,0873 393,0895

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 8, 8:30 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 6 more6 hr
May 8, 9:00 PM CDTSevere Thunderstorm WatchSPCHancock, Henderson, Jo Daviess, McDonough, Mercer, Rock Island and 1 more5 hr
May 9, 2:30 AM CDTSevere Thunderstorm WatchSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 9 more6 hr

Nearby

Severe Thunderstorm Watches in Illinois, 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.