Alert archive / Illinois / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 57, NWS Chicago, IL

July 5, 2003Iroquois County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 5, 2003, 2:45 PM CDT for Iroquois County, Illinois. It was in force for 45 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 5, 2003, 2:45 PM CDT (19:45 UTC)
Expired: Jul 5, 2003, 3:30 PM CDT
In force: 45 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 19:46 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 12:00Z, 7.8 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2306 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 771 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: 39 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 5, 12:45 PM CDT, 2 hours earlier.

Area forecast discussion, Jul 5, 12:45 PM CDT, 2 hours before

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Hazardous weather outlook, Jul 5, 6:00 AM CDT, 8 hours 45 minutes before

ILZ003>006-008-010>014-019-020>023-032-033-039-INZ001-002-010-011-019
-061100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CDT SAT JUL 5 2003

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF
NORTHERN ILLINOIS AND NORTHWEST INDIANA TONIGHT.

A BAND OF STRONG BUT WEAKING THUNDERSTORMS WITH LOCALLY STRONG WINDS
AND VERY HEAVY RAIN WILL MOVE OUT OF THE AREA BEFORE 800 AM. MOST OF
THE DAY SHOULD BE DRY BUT HUMID AGAIN. ANOTHER BAND OF THUNDERSTORMS
IS EXPECTED TO DEVELOP TO OUR WEST AND AFFECT NORTHERN ILLINOIS AND
NORTHWEST INDIANA AGAIN TONIGHT.  A FEW OF THESE MAY BE SEVERE WITH
THE PRIMARY THREAT FROM WIND.

.DAYS TWO THROUGH SEVEN... SUNDAY THROUGH FRIDAY

PERIODS OF THUNDERSTORMS ARE LIKELY INTO WEDNESDAY MORNING.  SOME OF
THESE MAY BE SEVERE.  DRIER AND COOLER AIR IS EXPECTED LATER
WEDNESDAY THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED FOR THE NEXT COUPLE HOURS AND
AGAIN TONIGHT.

&&

           NWS CHICAGO WEBPAGE

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

KL

In the hours before

Local storm report, Jul 5, 9:14 AM CDT, 5 hours 31 minutes before

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Local storm report, Jul 5, 9:55 AM CDT, 4 hours 50 minutes before

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  <link rel="stylesheet" href="index.css">
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<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 3:47 AM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle, Winnebago	58 min
Jul 5, 4:27 AM CDT	Severe Thunderstorm Warning	LOT	Boone, McHenry	48 min
Jul 5, 5:02 AM CDT	Severe Thunderstorm Warning	LOT	Cook, Kane, Lake	43 min
Jul 5, 5:07 AM CDT	Special Marine Warning	LOT		83 min
Jul 5, 5:07 AM CDT	Special Marine Warning	LOT		83 min
Jul 5, 5:07 AM CDT	Special Marine Warning	LOT		83 min
Jul 5, 5:59 AM CDT	Severe Thunderstorm Warning	LOT	Lake, Porter	46 min
Jul 5, 6:31 AM CDT	Flash Flood Warning	LOT	Jasper, Newton	3 hr
Jul 5, 3:14 PM CDT	Severe Thunderstorm Warning	LOT	Benton	46 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2003 Every 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.