Alert archive / Illinois / Severe Thunderstorm Warnings in 2005

Severe Thunderstorm Warning 71, NWS Chicago, IL

June 29, 2005LaSalle County, Livingston County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jun 29, 2005, 7:15 PM CDT for LaSalle County, Livingston County, Illinois. It was in force for 27 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
Jun 29, 2005, 7:15 PM CDT (00:15 UTC)
Expired
Jun 29, 2005, 7:42 PM CDT
In force
27 min
Issued by
NWS Chicago, IL
Area
Counties, with a storm outline in the text

Counties LaSalle County, IL, Livingston County, IL

The radar

The Chicago radar (KLOT), 76 km from the middle of the area, began a volume at 00:17 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

Davenport, (KDVN), launched 00:00Z, 0.3 hours before the alert went out and 159 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, Davenport, at 00:00Z on 2005-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1049 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, Davenport, at 00:00Z on 2005-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
1049 J/kg
Mixed-layer CIN
-131 J/kg
Mixed-layer LCL
1913 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
224 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

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 Jun 29, 6:45 PM CDT, 30 minutes earlier.

Area forecast discussion, Jun 29, 6:45 PM CDT, 30 minutes before
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Hazardous weather outlook, Jun 29, 4:30 PM CDT, 2 hours 45 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
430 PM CDT WED JUN 29 2005

ILZ003>006-008-010>014-019>022-023-032-033-039-INZ001-002-010-011-
019-301100-
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DU PAGE-COOK-
LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-
LAKE IN-PORTER-NEWTON-JASPER-BENTON-
430 PM CDT WED JUN 29 2005

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

.DAY ONE...TONIGHT

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

ISOLATED THUNDERSTORMS WILL CONTINUE THIS EVENING...MAINLY ALONG AND
SOUTH OF A LINE FROM THE ROCKFORD AREA THROUGH KANKAKEE AND INTO
NORTHWEST INDIANA SOUTH OF THE KANKAKEE RIVER.  BRIEF HEVY
DOWNPOURS...FREQUENT LIGHTNING AND PERHAPS SOME SMALL HAIL ARE
POSSIBLE WITH THESE STORMS.

THERE IS A BETTER CHANCE OF ORGANIZED THUNDERSTORMS AFTER MIDNIGHT.
SOME OF THESE STORMS MAY PRODUCE DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY

THERE WILL BE AN ONGOING CHANCE OF THUNDERSTORMS INTO THURSDAY
MORNING ACROSS THE ENTIRE FORECAST AREA. THE THREAT OF THUNDERSTORMS
WILL END FROM WEST TO EAST ACROSS THE REGION BY AFTERNOON AS A COLD
FRONT USHERS DRIER AIR ACROSS THE MIDWEST.

THUNDERSTORMS MAY OCCUR FROM LATE SUNDAY NIGHT INTO TUESDAY...WITH A
RETURN OF WARM AND HUMID AIR.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATE TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)

LMZ740>745-766-301100-
WINTHROP HARBOR IL TO MICHIGAN CITY IN-
LAKE MICHIGAN-
430 PM CDT WED JUN 29 2005

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

.DAY ONE... TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS AFTER MIDNIGHT. SOME OF THESE
STORMS MAY PRODUCE BRIEF WIND GUSTS IN EXCESS OF 35 KNOTS.

.DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY

THERE WILL BE AN ONGOING CHANCE OF THUNDERSTORMS INTO THURSDAY
MORNING ACROSS SOUTHERN LAKE MICHIGAN. THE THREAT OF THUNDERSTORMS
WILL END FROM WEST TO EAST ACROSS THE LAKE BY AFTERNOON AS A COLD
FRONT USHERS DRIER AIR ACROSS WESTERN GREAT LAKES REGION.

THUNDERSTORMS ARE AGAIN POSSIBLE MONDAY AND TUESDAY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)

MERZLOCK

In the hours before

Local storm report, Jun 29, 6:29 PM CDT, 46 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 4:37 AM CDTSevere Thunderstorm WarningLOTDeKalb, DuPage, Kane, Kendall35 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2005Every severe thunderstorm warning in 2005

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.