Alert archive / Illinois / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 115, NWS Chicago, IL

July 15, 2003Cook County, DuPage County, Kane County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 15, 2003, 4:18 AM CDT for Cook County, DuPage County, Kane County, Illinois. It was in force for 42 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 15, 2003, 4:18 AM CDT (09:18 UTC)
Expired
Jul 15, 2003, 5:00 AM CDT
In force
42 min
Issued by
NWS Chicago, IL
Area
Counties, with a storm outline in the text

Counties Cook County, IL, DuPage County, IL, Kane County, IL

The radar

The Chicago radar (KLOT), 32 km from the middle of the area, began a volume at 09:21 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, 9.3 hours before the alert went out and 205 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 2003-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2003-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2108 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 15, 3:20 AM CDT, 58 minutes earlier.

Area forecast discussion, Jul 15, 3:20 AM CDT, 58 minutes before
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Hazardous weather outlook, Jul 14, 5:12 PM CDT, 11 hours 6 minutes before
ILZ003>006-008-010>014-019-020>023-032-033-039-INZ001-002-010-011-019
-151100-

HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE CHICAGO IL
345 PM CDT MON JUL 14 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 RISK OF SEVERE THUNDERSTORMS AFTER MIDNIGHT ACROSS
THE OUTLOOK REGION.

THUNDERSTORMS WILL FORM AHEAD OF A COLD FRONT THAT WILL MOVE INTO
INTO NORTHWEST ILLINOIS AND CENTRAL WISCONSIN BY TUESDAY MORNING.
THUNDERSTORMS WILL LIKELY MOVE INTO THE ROCKFORD AND DIXON AREAS OF
NORTH CENTRAL ILLINOIS AROUND MIDNIGHT...THEN MOVE TO APPROXIMATELY
A CHICAGO TO WATSEKA LINE DURING THE EARLY MORNING HOURS...AND INTO
NORTHWEST INDIANA AROUND SUNRISE.

THE MAIN THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY

THUNDERSTORMS WILL LINGER INTO TUESDAY MORNING...ESPECIALLY ACROSS
EASTERN PORTIONS OF THE OUTLOOK AREA. THE NEXT CHANCE OF
THUNDERSTORMS AFTER TUESDAY WILL BE FROM LATE THURSDAY NIGHT THROUGH
SATURDAY MORNING.

FLOODING CONTINUES ON THE IROQUOIS RIVER IN IROQUOIS COUNTY IN
ILLINOIS. SEE THE LATEST FLOOD STATEMENTS FOR FURTHER DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS MAY BE NEEDED OVERNIGHT TONIGHT.

&&

           NWS CHICAGO WEBPAGE

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

RATZER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 15, 3:17 AM CDTSpecial Marine WarningLOT103 min
Jul 15, 4:26 AM CDTSpecial Marine WarningLOT2 hr
Jul 15, 4:26 AM CDTSpecial Marine WarningLOT2 hr
Jul 15, 4:58 AM CDTSevere Thunderstorm WarningLOTCook, Will32 min
Jul 15, 5:25 AM CDTSevere Thunderstorm WarningLOTGrundy, Kankakee, Will35 min
Jul 15, 6:20 AM CDTSevere Thunderstorm WarningLOTIroquois25 min

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.