Alert archive / Illinois / Tornado Watches in 2003

Tornado Watch 930

September 26, 200324 counties in Illinois; 17 counties in Indiana

The Storm Prediction Center issued this tornado watch at Sep 26, 2003, 4:50 PM CDT for 24 counties in Illinois; 17 counties in Indiana. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Sep 26, 2003, 4:50 PM CDT (21:50 UTC)
Expired
Sep 26, 2003, 10:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 41 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Jasper County, IL, Logan County, IL, Macon County, IL, Madison County, IL, Menard County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Sangamon County, IL, Shelby County, IL, Vermilion County, IL, Boone County, IN, Clay County, IN, Clinton County, IN, Fountain County, IN, Greene County, IN, Hendricks County, IN, Lawrence County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Sullivan County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN

The radar

The Lincoln radar (KILX), 90 km from the middle of the area, began a volume at 21:53 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

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

IssuedProductOfficeCountiesLasted
Sep 26, 7:23 PM CDTFlash Flood WarningINDFountain, Tippecanoe2 hr

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 12:00Z, 9.8 hours before the alert went out and 54 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 2003-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2003-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2018 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
246 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 262148
SEL0  
SPC WW 262150
ILZ000-INZ000-270300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 930 
NWS STORM PREDICTION CENTER NORMAN OK 
450 PM CDT FRI SEP 26 2003

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

       CENTRAL ILLINOIS
       WEST CENTRAL INDIANA

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 450 PM UNTIL 1000
PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF SPRINGFIELD
ILLINOIS TO 35 MILES NORTH NORTHEAST OF BLOOMINGTON INDIANA.

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...CONTINUE...WW 928...WW 929...


DISCUSSION...LINE OF SEVERE STORMS WILL CONTINUE TO TRACK EASTWARD
ACROSS CENTRAL IL INTO CENTRAL IND THIS EVENING.  VERY STRONG LOW
LEVEL WIND FIELDS HAVE DEVELOPED IN THIS REGION...ALONG AND NORTH OF
RETREATING SURFACE WARM FRONT. ISOLATED SUPERCELLS HAVE INTENSIFIED
WITHIN SQUALL LINE...AND OTHER ROTATING STORMS MAY DEVELOP AHEAD OF
LINE IN REGION OF STRONG LOW LEVEL WARM ADVECTION.  DAMAGING WINDS
AND HAIL ARE THE MAIN THREAT...BUT POTENTIAL FOR ISOLATED TORNADOES
ALSO EXISTS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 26035.


...HART

401,0895 402,0862 384,0862 383,0895 

WWUS20 KWNS 262148
SEL0  
SPC WW 262150
ILZ000-INZ000-270300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 930 
NWS STORM PREDICTION CENTER NORMAN OK 
450 PM CDT FRI SEP 26 2003

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

       CENTRAL ILLINOIS
       WEST CENTRAL INDIANA

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 450 PM UNTIL 1000
PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF SPRINGFIELD
ILLINOIS TO 35 MILES NORTH NORTHEAST OF BLOOMINGTON INDIANA.

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...CONTINUE...WW 928...WW 929...


DISCUSSION...LINE OF SEVERE STORMS WILL CONTINUE TO TRACK EASTWARD
ACROSS CENTRAL IL INTO CENTRAL IND THIS EVENING.  VERY STRONG LOW
LEVEL WIND FIELDS HAVE DEVELOPED IN THIS REGION...ALONG AND NORTH OF
RETREATING SURFACE WARM FRONT. ISOLATED SUPERCELLS HAVE INTENSIFIED
WITHIN SQUALL LINE...AND OTHER ROTATING STORMS MAY DEVELOP AHEAD OF
LINE IN REGION OF STRONG LOW LEVEL WARM ADVECTION.  DAMAGING WINDS
AND HAIL ARE THE MAIN THREAT...BUT POTENTIAL FOR ISOLATED TORNADOES
ALSO EXISTS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 26035.


...HART

401,0895 402,0862 384,0862 383,0895

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 26, 12:21 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Christian, DeWitt and 23 more114 min
Sep 26, 1:20 PM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 26 more6 hr
Sep 26, 4:32 PM CDTMesoscale DiscussionSPCChampaign, Christian, Clark, Clay, Coles, Crawford and 19 more88 min
Sep 26, 5:06 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 26 more84 min
Sep 26, 6:10 PM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more7 hr
Sep 26, 6:59 PM CDTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Coles and 17 more91 min
Sep 26, 5:45 PM CDTMesoscale DiscussionSPCBartholomew, Blackford, Brown, Dearborn, Decatur, Delaware and 22 more2 hr

Nearby

Tornado Watches in Illinois, 2003Tornado Watches in Indiana, 2003Every tornado 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.