Alert archive / Illinois / Tornado Watches in 2004

Tornado Watch 444

June 11, 200421 counties in Illinois

The Storm Prediction Center issued this tornado watch at Jun 11, 2004, 11:00 PM CDT for 21 counties in Illinois. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jun 11, 2004, 11:00 PM CDT (04:00 UTC)
Expired
Jun 12, 2004, 4:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 21 counties

Bureau County, IL, Carroll County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, Ogle County, IL, Putnam County, IL, Stark County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL

The radar

The Chicago radar (KLOT), 86 km from the middle of the area, began a volume at 03:59 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

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

IssuedProductOfficeCountiesLasted
Jun 11, 11:09 PM CDTSevere Thunderstorm WarningLOTGrundy, Kendall, Will41 min
Jun 11, 11:25 PM CDTFlash Flood WarningLOTCook, DuPage, Grundy, Kane, Kendall, Will4 hr
Jun 12, 12:10 AM CDTFlash Flood WarningDVNStephenson5 hr
Jun 12, 1:36 AM CDTSevere Thunderstorm WarningLOTIroquois24 min
Jun 12, 2:07 AM CDTFlash Flood WarningLOTIroquois4 hr
Jun 12, 2:31 AM CDTFlash Flood WarningLOTOgle3 hr
Jun 12, 2:49 AM CDTFlash Flood WarningLOTLaSalle3 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 00:00Z, 4.0 hours before the alert went out and 174 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 2004-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3388 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 00:00Z on 2004-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
3388 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1075 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 120358
SEL4  
SPC WW 120400
ILZ000-LMZ000-120900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 444
NWS STORM PREDICTION CENTER NORMAN OK
1100 PM CDT FRI JUN 11 2004

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

       NORTHERN ILLINOIS
       LAKE MICHIGAN

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 1100 PM
UNTIL 400 AM CDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 65 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 50 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 85 MILES WEST NORTHWEST OF MARSEILLES
ILLINOIS TO 65 MILES EAST SOUTHEAST OF MARSEILLES 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 TORNADO
WATCH NUMBER 440. WATCH NUMBER 440 WILL NOT BE IN EFFECT AFTER
1100 PM CDT. CONTINUE...WW 439...WW 441...WW 443...

DISCUSSION...SCATTERED THUNDERSTORMS/POSSIBLE SUPERCELLS EXPECTED TO
PERSIST INVOF WARM/STATIONARY FRONT TONIGHT...WHERE MOIST INFLOW/LOW
LCLS AND ENHANCED LOW LEVEL SHEAR WILL REMAIN FAVORABLE FOR POSSIBLE
TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 55 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 27030.


...CORFIDI

423,0901 414,0873 401,0873 410,0901

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 9:35 PM CDTSevere Thunderstorm WatchSPCHenderson, Mercer4 hr
Jun 11, 10:04 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, Grundy, Jo Daviess and 10 more56 min
Jun 12, 1:48 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 19 more87 min
Jun 12, 3:08 AM CDTMesoscale DiscussionSPCCook, DeKalb, DuPage, Grundy, Iroquois, Kane and 7 more97 min
Jun 12, 10:48 AM CDTMesoscale DiscussionSPCGallatin, Hardin, Massac, Pope2 hr
Jun 12, 3:45 PM CDTSevere Thunderstorm WatchSPCHenderson, Mercer, Rock Island, Warren5 hr
Jun 12, 3:51 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 11 more84 min
Jun 12, 4:15 PM CDTSevere Thunderstorm WatchSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more5 hr
Jun 12, 6:08 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more37 min

Nearby

Tornado Watches in Illinois, 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.