Alert archive / Illinois / Tornado Watches in 2004

Tornado Watch 261

May 23, 200422 counties in Illinois; Des Moines County, Lee County, Iowa; 19 counties in Missouri

The Storm Prediction Center issued this tornado watch at May 23, 2004, 1:15 PM CDT for 22 counties in Illinois; Des Moines County, Lee County, Iowa; 19 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 23, 2004, 1:15 PM CDT (18:15 UTC)
Expired
May 23, 2004, 7:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 43 counties

Des Moines County, IA, Lee County, IA, Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Henderson County, IL, Knox County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Morgan County, IL, Peoria County, IL, Pike County, IL, Schuyler County, IL, Scott County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Woodford County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Clark County, MO, Cole County, MO, Cooper County, MO, Howard County, MO, Lewis County, MO, Lincoln County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 115 km from the middle of the area, began a volume at 18:15 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

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

IssuedProductOfficeCountiesLasted
May 23, 2:53 PM CDTSevere Thunderstorm WarningLSXBoone37 min
May 23, 3:37 PM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole38 min
May 23, 4:11 PM CDTSevere Thunderstorm WarningLSXCallaway, Osage49 min
May 23, 4:36 PM CDTSevere Thunderstorm WarningLSXPike39 min
May 23, 4:45 PM CDTSevere Thunderstorm WarningLSXFranklin, Gasconade, Montgomery, Warren60 min
May 23, 5:06 PM CDTTornado WarningILXScott54 min
May 23, 5:36 PM CDTSevere Thunderstorm WarningLSXFranklin, Saint Charles, Warren39 min
May 23, 5:42 PM CDTTornado WarningILXMorgan63 min
May 23, 6:11 PM CDTSevere Thunderstorm WarningLSXFranklin, Saint Charles, Saint Louis, City of Saint Louis49 min
May 23, 6:13 PM CDTSevere Thunderstorm WarningLSXFranklin, Saint Charles, Saint Louis, City of Saint Louis47 min
May 23, 6:20 PM CDTSevere Thunderstorm WarningLSXFranklin, Warren25 min
May 23, 6:43 PM CDTTornado WarningILXMorgan32 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

Lincoln, IL (KILX), launched 12:00Z, 6.3 hours before the alert went out and 253 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 2004-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 435 joules per kilogram.LCLLFCEL10008507005003002001001 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 2004-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
435 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
621 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 231817
SEL1  
SPC WW 231815
IAZ000-ILZ000-MOZ000-240000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 261
NWS STORM PREDICTION CENTER NORMAN OK
115 PM CDT SUN MAY 23 2004

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

       EXTREME SOUTHEAST IOWA
       WEST CENTRAL ILLINOIS
       NORTHEAST AND EAST CENTRAL MISSOURI

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 115 PM UNTIL 700
PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE 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 65 STATUTE MILES EAST AND WEST
OF A LINE FROM 10 MILES SOUTH SOUTHEAST OF JEFFERSON CITY MISSOURI
TO 35 MILES NORTH NORTHWEST OF PEORIA 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...CONTINUE...WW 259...WW 260...

DISCUSSION...AIRMASS OVER NORTHEAST MO AND WEST CENTRAL IL IS SLOWLY
DESTABILIZING AHEAD OF APPROACHING SURFACE COLD FRONT. SCATTERED
THUNDERSTORMS ARE EXPECTED TO FORM ALONG THE FRONT AND TRACK
EASTWARD ACROSS CENTRAL IL THIS AFTERNOON.  VERTICAL SHEAR PROFILES
AND LOW LEVEL MOISTURE VALUES INDICATE THE POTENTIAL FOR TORNADIC
SUPERCELLS.  POTENTIAL FOR A FEW STRONG TORNADOES EXISTS IF FURTHER
SURFACE HEATING CAN OCCUR THROUGH THE AFTERNOON.

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 25035.


...HART

382,0931 410,0911 410,0884 382,0905

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 8:58 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 23 more92 min
May 23, 12:24 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 32 more66 min
May 23, 12:40 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 27 more5 hr
May 23, 1:21 AM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 6 more24 min
May 23, 1:40 AM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, Fulton, Hancock, Logan and 8 more4 hr
May 23, 4:30 AM CDTMesoscale DiscussionSPCAdams, Boone, Brown, Bureau, Carroll, Cass and 44 more60 min
May 23, 10:45 AM CDTTornado WatchSPCClark, Clay, Coles, Crawford, Cumberland, Edgar and 19 more5 hr
May 23, 12:25 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Calhoun, Carroll, Cass and 31 more95 min
May 23, 12:45 PM CDTMesoscale DiscussionSPCClark, Clay, Coles, Crawford, Cumberland, Edgar and 18 more2 hr
May 23, 2:05 PM CDTTornado WatchSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 18 more8 hr
May 23, 2:53 PM CDTMesoscale DiscussionSPCIroquois, Vermilion67 min
May 23, 3:50 PM CDTTornado WatchSPCCook, DuPage, Iroquois, Kankakee, Vermilion, Will6 hr
May 23, 4:35 PM CDTSevere Thunderstorm WatchSPCMonroe5 hr
May 23, 5:00 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 28 more2 hr
May 23, 5:10 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 17 more95 min
May 23, 5:30 PM CDTTornado WatchSPCBond, Calhoun, Christian, Clark, Clay, Clinton and 29 more6 hr
May 23, 6:30 PM CDTMesoscale DiscussionSPCCook, DuPage, Iroquois, Kankakee, Vermilion, Will2 hr
May 22, 7:11 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Clarke, Dallas and 15 more94 min
May 22, 7:23 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Dallas, Fremont and 9 more67 min
May 22, 10:40 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Benton, Cedar, Clarke and 33 more5 hr
May 22, 11:33 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Benton, Cedar, Clarke and 33 more87 min
May 23, 2:21 AM CDTMesoscale DiscussionSPCAppanoose, Buchanan, Cedar, Davis, Delaware, Des Moines and 14 more54 min

Nearby

Tornado Watches in Illinois, 2004Tornado Watches in Missouri, 2004Tornado Watches in Iowa, 2004Every tornado 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.