Alert archive / Illinois / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 137, NWS Chicago, IL

July 18, 2003Iroquois County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 18, 2003, 3:19 AM CDT for Iroquois County, Illinois. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 18, 2003, 3:19 AM CDT (08:19 UTC)
Expired
Jul 18, 2003, 4:00 AM CDT
In force
41 min
Issued by
NWS Chicago, IL
Area
Counties, with a storm outline in the text

County Iroquois County, IL

The radar

The Chicago radar (KLOT), 98 km from the middle of the area, began a volume at 08:20 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.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 8.3 hours before the alert went out and 93 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 2003-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2256 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 2003-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 square meters per square second.193958Sfc1 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
2256 J/kg
Mixed-layer CIN
-134 J/kg
Mixed-layer LCL
1630 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 18, 3:00 AM CDT, 19 minutes earlier.

Area forecast discussion, Jul 18, 3:00 AM CDT, 19 minutes before
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Hazardous weather outlook, Jul 17, 4:30 PM CDT, 10 hours 49 minutes before
ILZ003>006-008-010>014-019-020>023-032-033-039-
INZ001-002-010-011-019-181100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
430 PM CDT THU JUL 17 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST
ILLINOIS...NORTHWEST INDIANA...AND THE ADJACENT WATERS OF LAKE
MICHIGAN.

.DAY ONE... TONIGHT

THERE IS A SLIGHT CHANCE OF SEVERE THUNDERSTORMS THIS EVENING OVER
THE ENTIRE OUTLOOK AREA.

A COLD FRONT WILL SWEEP FROM THE UPPER MISSISSIPPI VALLEY ACROSS
THE OUTLOOK AREA FROM NORTH TO SOUTH THIS EVENING. VERY MOIST AND
UNSTABLE AIR IN THE OUTLOOK AREA AND INCREASINGLY FAVORABLE DYNAMICS
WILL TRIGGER THUNDERSTORM DEVELOPMENT.

LARGE HAIL AND DAMAGING WINDS ARE THE MAIN THREATS WITH THESE
STORMS. THE MOST LIKELY TIMEFRAME FOR HAZARDOUS WEATHER WILL BE
UNTIL 8PM...ALTHOUGH SEVERE WEATHER MAY OCCUR SEVERAL HOURS EITHER
SIDE OF THIS TIME WINDOW.

.DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY

THE NEXT CHANCE OF THUNDERSTORMS IS SUNDAY THROUGH MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE NEEDED THIS EVENING.

&&

           NWS CHICAGO WEBPAGE

    HTTP://WWW.CRH.NOAA.GOV/LOT (LOWER CASE)
OR  HTTP://WEATHER.NOAA.GOV/CHICAGO (LOWER CASE)

In the hours before

Local storm report, Jul 17, 11:49 PM CDT, 3 hours 30 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
1149 PM CDT THU JUL 17 2003

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0950 PM    3 N MINOOKA               IL   WIND DAMAGE
07/17/03   KENDALL                        SMALL TREE LIMBS AND
                                          POWER LINES DOWN.
                                          REPORTED BY STORM
                                          SPOTTER.

1000 PM    BOURBONNAIS               IL   .75 INCH HAIL
07/17/03   KANKAKEE                       NEAR OLIVET NAZARENE
                                          UNIVERSITY. REPORTED BY
                                          STORM SPOTTER.

1000 PM    BRADLEY                   IL   WIND DAMAGE
07/17/03   KANKAKEE                       LARGE LIMBS DOWN,
                                          NUMEROUS TREES AND
                                          POWER LINES DOWN
                                          THROUGHOUT THE VILLAGE.
                                          . REPORTED BY STORM
                                          SPOTTER.
Local storm report, Jul 17, 11:57 PM CDT, 3 hours 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
1157 PM CDT THU JUL 17 2003

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0600 PM    ELSDON                    IL   1.75 INCH HAIL
07/17/03   COOK                           54TH AND KEELER.
                                          REPORTED BY PUBLIC.

0640 PM    STEGER                    IL   WIND DAMAGE
07/17/03   WILL                           LARGE TREES
                                          DOWN/UPROOTED NEAR RT 1
                                          AND COOK/WILL COUNTY
                                          LINE. . REPORTED BY
                                          STORM SPOTTER.
Local storm report, Jul 18, 12:41 AM CDT, 2 hours 38 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
1242 PM CDT FRI JUL 18 2003

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1030 PM    8 NE MARSEILLES           IL   .75 INCH HAIL
07/17/03   LASALLE                        STREET FLOODING,
                                          TRAFFIC STOPPED ON
                                          I-80. REPORTED BY STORM
                                          SPOTTER.

1030 PM    ST CHARLES                IL   1.5 INCH HAIL
07/17/03   KANE                           REPORTED BY PUBLIC.
Special weather statement, Jul 18, 12:50 AM CDT, 2 hours 29 minutes before
>ILZ032-ILZ033-ILZ039-180800-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
1250 AM CDT FRI JUL 18 2003

ILZ032-033-180800-
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS CLEARED A PORTION OF
SEVERE THUNDERSTORM WATCH 755. COUNTIES CLEARED INCLUDE:

IN ILLINOIS:
IROQUOIS...LIVINGSTON...

THIS INCLUDES THE CITIES OF...PONTIAC...WATSEKA...

ILZ039-180800-
SEVERE THUNDERSTORM WATCH 755 REMAINS VALID UNTIL 300 AM CDT
FRIDAY FOR THE FOLLOWING COUNTIES:

IN ILLINOIS:
FORD...

THIS INCLUDES THE CITY OF GIBSON CITY...
Special weather statement, Jul 18, 12:52 AM CDT, 2 hours 27 minutes before
>ILZ010-ILZ039-180800-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
1252 AM CDT FRI JUL 18 2003

ILZ010-180800-
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS CLEARED A PORTION OF
SEVERE THUNDERSTORM WATCH 755. COUNTIES CLEARED INCLUDE:

IN ILLINOIS:
LEE...

THIS INCLUDES THE CITY OF DIXON...

ILZ039-180800-
SEVERE THUNDERSTORM WATCH 755 REMAINS VALID UNTIL 300 AM CDT
FRIDAY FOR THE FOLLOWING COUNTIES:

IN ILLINOIS:
FORD...

THIS INCLUDES THE CITY OF GIBSON CITY...
Local storm report, Jul 18, 1:09 AM CDT, 2 hours 10 minutes before
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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 7:58 PM CDTSevere Thunderstorm WarningLOTCook, DuPage62 min
Jul 17, 8:21 PM CDTSevere Thunderstorm WarningLOTKane24 min
Jul 17, 8:51 PM CDTSevere Thunderstorm WarningLOTDeKalb, DuPage, Kane, Kendall, LaSalle, Will39 min
Jul 17, 8:55 PM CDTSevere Thunderstorm WarningLOTDuPage, Kane, Will35 min
Jul 17, 10:03 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Kankakee42 min
Jul 17, 10:31 PM CDTSevere Thunderstorm WarningLOTLaSalle59 min
Jul 17, 10:41 PM CDTSevere Thunderstorm WarningLOTIroquois49 min
Jul 17, 10:56 PM CDTSevere Thunderstorm WarningLOTFord, Livingston64 min
Jul 18, 1:21 AM CDTSevere Thunderstorm WarningLOTFord24 min
Jul 18, 2:56 AM CDTSevere Thunderstorm WarningLOTFord, Livingston49 min
Jul 17, 7:00 PM CDTTornado WarningLOTLake, Newton30 min
Jul 17, 7:01 PM CDTTornado WarningLOTLake, Newton29 min
Jul 17, 7:17 PM CDTFlash Flood WarningLOTLake4 hr
Jul 17, 7:30 PM CDTSevere Thunderstorm WarningLOTJasper, Newton45 min
Jul 17, 8:00 PM CDTSevere Thunderstorm WarningLOTLake, Porter45 min
Jul 17, 8:22 PM CDTSevere Thunderstorm WarningLOTBenton23 min
Jul 17, 10:45 PM CDTFlash Flood WarningLOTLake4 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2003Every severe thunderstorm warning 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.