Alert archive / Illinois / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 62, NWS Chicago, IL

May 21, 2004Lake County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 21, 2004, 9:49 AM CDT for Lake County, Illinois. It was in force for 26 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
May 21, 2004, 9:49 AM CDT (14:49 UTC)
Expired
May 21, 2004, 10:15 AM CDT
In force
26 min
Issued by
NWS Chicago, IL
Area
Counties, with a storm outline in the text

County Lake County, IL

The radar

The Chicago radar (KLOT), 85 km from the middle of the area, began a volume at 14:49 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.

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 May 21, 6:15 AM CDT, 3 hours 34 minutes earlier.

Area forecast discussion, May 21, 6:15 AM CDT, 3 hours 34 minutes before
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Hazardous weather outlook, May 21, 6:00 AM CDT, 3 hours 49 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CDT FRI MAY 21 2004

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-
019-221100-
BENTON-BOONE-COOK-DE KALB-DU PAGE-FORD-GRUNDY-IROQUOIS-JASPER-
KANE-KANKAKEE-KENDALL-LA SALLE-LAKE-LAKE IN-LEE-LIVINGSTON-
MCHENRY-NEWTON-OGLE-PORTER-WILL-WINNEBAGO-
600 AM CDT FRI MAY 21 2004

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH
CENTRAL AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE ENTIRE
AREA.

A FRONTAL BOUNDARY EXTENDING FROM CENTRAL IOWA TO CENTRAL INDIANA
WILL RETURN NORTHWARD AS A WARM FRONT TODAY.  THIS FRONT WILL
SEPARATE RELATIVELY COOL AIR TO THE NORTH FROM WARM AND STICKY AIR
TO THE SOUTH.  THE MAIN FOCUS FOR THUNDERSTORM DEVELOPMENT WILL BE
TO THE NORTH OF THIS FRONT.  HOWEVER...SCATTERED THUNDERSTORMS WILL
LIKELY DEVELOP LATE THIS AFTERNOON AND TONIGHT...IN THE UNSTABLE AIR
ALONG AND JUST SOUTH OF THIS BOUNDARY AS WELL.

THE PRIMARY THREAT WITH STRONGER STORMS WILL BE LARGE HAIL AND
THUNDERSTORM WIND GUSTS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS AGAIN SATURDAY AND
SATURDAY NIGHT.  IN ADDITION...A HEAVY RAINFALL POTENTIAL ALSO
EXISTS FOR SATURDAY AFTERNOON AND SATURDAY NIGHT.

THUNDERSTORMS MAY CONTINUE THROUGH SUNDAY...BEFORE A COLD FRONT
PUSHES TROUGH THE MIDWEST AND TEMPORARILY ENDS THE STORM THREAT.

THUNDERSTORMS ARE POSSIBLE AGAIN LATE MONDAY NIGHT AND TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BECOME NECESSARY TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WWW.CRH.NOAA.GOV/LOT (LOWER CASE)

LMZ740>746-766-221100-
WINTHROP HARBOR TO WILMETTE HARBOR-WILMETTE HARBOR TO NORTHERLY
ISLAND-NORTHERLY ISLAND TO CALUMET HARBOR-CALUMET HARBOR TO GARY-
GARY TO BURNS HARBOR-BURNS HARBOR TO MICHIGAN CITY-MICHIGAN CITY
TO NEW BUFFALO-LAKE MICHIGAN-
600 AM CDT FRI MAY 21 2004

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS
AND INDIANA WATERS OF LAKE MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE ENTIRE
AREA.

A FRONTAL BOUNDARY EXTENDING FROM CENTRAL IOWA TO CENTRAL INDIANA
WILL RETURN NORTHWARD AS A WARM FRONT TODAY.  THIS FRONT WILL
SEPARATE RELATIVELY COOL AIR TO THE NORTH FROM WARM AND STICKY AIR
TO THE SOUTH.  THE MAIN FOCUS FOR THUNDERSTORM DEVELOPMENT WILL BE
TO THE NORTH OF THIS FRONT.  HOWEVER...SCATTERED THUNDERSTORMS WILL
LIKELY DEVELOP LATE THIS AFTERNOON AND TONIGHT...IN THE UNSTABLE AIR
ALONG AND JUST SOUTH OF THIS BOUNDARY AS WELL.

THE PRIMARY THREATS WITH STRONGER STORMS WILL BE LARGE HAIL...
THUNDERSTORM WIND GUSTS ABOVE 35 KNOTS...AND FREQUENT LIGHTNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS AGAIN SATURDAY AND
SATURDAY NIGHT.  IN ADDITION...A HEAVY RAINFALL POTENTIAL ALSO
EXISTS FOR SATURDAY AFTERNOON AND SATURDAY NIGHT.

THUNDERSTORMS MAY CONTINUE THROUGH SUNDAY...BEFORE A COLD FRONT
PUSHES TROUGH THE MIDWEST AND TEMPORARILY ENDS THE STORM THREAT.

THUNDERSTORMS ARE POSSIBLE AGAIN LATE MONDAY NIGHT AND TUESDAY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WWW.CRH.NOAA.GOV/LOT (LOWER CASE)

MERZLOCK

In the hours before

Local storm report, May 21, 9:31 AM CDT, 18 minutes before
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Local storm report, May 21, 9:49 AM CDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 7:00 PM CDTSevere Thunderstorm WarningLOTWinnebago60 min
May 20, 7:03 PM CDTSpecial Marine WarningLOT87 min
May 20, 7:03 PM CDTSpecial Marine WarningLOT87 min
May 20, 7:20 PM CDTFlash Flood WarningLOTBoone, McHenry3 hr
May 20, 7:31 PM CDTFlash Flood WarningLOTDeKalb, Kane, Lee, Ogle3 hr
May 20, 7:49 PM CDTSevere Thunderstorm WarningLOTLake41 min
May 20, 8:03 PM CDTFlash Flood WarningLOTCook, DuPage3 hr
May 20, 8:07 PM CDTSevere Thunderstorm WarningLOTDeKalb, Kane53 min
May 20, 8:09 PM CDTSevere Thunderstorm WarningLOTCook, DuPage51 min
May 20, 8:19 PM CDTSpecial Marine WarningLOT116 min
May 20, 8:19 PM CDTSpecial Marine WarningLOT116 min
May 20, 8:57 PM CDTSevere Thunderstorm WarningLOTCook, DuPage48 min
May 20, 8:58 PM CDTSevere Thunderstorm WarningLOTDeKalb, Kane47 min
May 20, 9:02 PM CDTSevere Thunderstorm WarningLOTMcHenry43 min
May 20, 9:44 PM CDTSevere Thunderstorm WarningLOTCook, Lake31 min
May 20, 10:00 PM CDTSevere Thunderstorm WarningLOTLaSalle, Livingston60 min
May 20, 10:08 PM CDTSpecial Marine WarningLOT52 min
May 20, 10:08 PM CDTSpecial Marine WarningLOT52 min
May 20, 10:20 PM CDTFlash Flood WarningLOTCook, DeKalb, DuPage, Kane, LaSalle, Lee and 1 more3 hr
May 20, 10:42 PM CDTSevere Thunderstorm WarningLOTGrundy48 min
May 20, 10:59 PM CDTSevere Thunderstorm WarningLOTLivingston31 min
May 20, 11:41 PM CDTSevere Thunderstorm WarningLOTKankakee34 min
May 21, 8:25 AM CDTSpecial Marine WarningLOT95 min
May 21, 8:25 AM CDTSpecial Marine WarningLOT95 min
May 21, 9:00 AM CDTSevere Thunderstorm WarningLOTBoone, Winnebago30 min
May 21, 9:43 AM CDTSevere Thunderstorm WarningLOTCook, DuPage, Kane47 min
May 21, 9:52 AM CDTSpecial Marine WarningLOT83 min
May 21, 9:52 AM CDTSpecial Marine WarningLOT83 min
May 21, 5:46 PM CDTSpecial Marine WarningLOT2 hr
May 21, 5:46 PM CDTSpecial Marine WarningLOT2 hr
May 21, 12:00 AM CDTSevere Thunderstorm WarningLOTPorter30 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2004Every severe thunderstorm warning 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; radar from the NEXRAD Level II archive.