Alert archive / Illinois / Severe Thunderstorm Warnings in 2004
Severe Thunderstorm Warning 175, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Aug 17, 2004, 5:12 PM CDT for Will County, Illinois. It was in force for 48 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
- Aug 17, 2004, 5:12 PM CDT (22:12 UTC)
- Expired
- Aug 17, 2004, 6:00 PM CDT
- In force
- 48 min
- Issued by
- NWS Chicago, IL
- Area
- Counties, with a storm outline in the text
County Will County, IL
The radar
The Chicago radar (KLOT), 20 km from the middle of the area, began a volume at 22:11 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 17, 1:20 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 10.2 hours before the alert went out and 153 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.
- Mixed-layer CAPE
- 127 J/kg
- Mixed-layer CIN
- -124 J/kg
- Mixed-layer LCL
- 932 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 103 m²/s²
- 0-3 km storm-relative helicity
- 92 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 Aug 17, 4:30 PM CDT, 42 minutes earlier.
Area forecast discussion, Aug 17, 4:30 PM CDT, 42 minutes before
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</html>Hazardous weather outlook, Aug 17, 5:00 PM CDT, 12 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO IL 500 PM CDT TUE AUG 17 2004 ILZ003>006-008-010>014-019>022-023-032-033-039-INZ001-002-010-011-019 -181100- 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- 500 PM CDT TUE AUG 17 2004 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 WEATHER EARLY THIS EVENING. THERE WILL BE SCATTERED THUNDERSTORMS THIS EVENING SOUTHEAST OF A QUAD CITIES TO DEKALB TO WAUKEGAN LINE. SOME OF THE STORMS COULD PRODUCE STRONG WINDS OR LARGE HAIL EARLY THIS EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE IS CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. THERE IS A SLIGHT RISK OF SEVERE WEATHER WITH THESE STORMS. THERE IS ANOTHER CHANCE OF THUNDERSTORMS THURSDAY NIGHT AND FRIDAY...AND AGAIN MONDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION NECESSARY THIS EVENING...AND MAY BE NEEDED WEDNESDAY AFTERNOON AND EVENING. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WWW.CRH.NOAA.GOV/LOT (LOWER CASE) LMZ740>746-766-181100- 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- 500 PM CDT TUE AUG 17 2004 THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS AND INDIANA WATERS OF LAKE MICHIGAN. .DAY ONE...TONIGHT THERE WILL BE SCATTERED THUNDERSTORMS THIS EVENING. THERE IS A SLIGHT RISK OF SEVERE WEATHER EARLY THIS EVENING. SOME OF THE STORMS COULD PRODUCE STRONG WINDS OR LARGE HAIL. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE IS CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. THERE IS A SLIGHT RISK OF SEVERE WEATHER WITH THESE STORMS. THERE IS ANOTHER CHANCE OF THUNDERSTORMS FRIDAY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WWW.CRH.NOAA.GOV/LOT (LOWER CASE)
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 17, 4:34 PM CDT | Severe Thunderstorm Warning | LOT | LaSalle | 56 min |
| Aug 17, 5:22 PM CDT | Severe Thunderstorm Warning | LOT | Cook | 68 min |
| Aug 17, 5:45 PM CDT | Special Marine Warning | LOT | 60 min | |
| Aug 17, 5:45 PM CDT | Special Marine Warning | LOT | 60 min | |
| Aug 17, 5:45 PM CDT | Special Marine Warning | LOT | 60 min | |
| Aug 17, 6:09 PM CDT | Severe Thunderstorm Warning | LOT | Grundy | 66 min |
| Aug 17, 6:23 PM CDT | Severe Thunderstorm Warning | LOT | LaSalle | 67 min |
| Aug 17, 6:45 PM CDT | Special Marine Warning | LOT | 45 min | |
| Aug 17, 6:45 PM CDT | Special Marine Warning | LOT | 45 min | |
| Aug 17, 6:05 PM CDT | Severe Thunderstorm Warning | LOT | Lake, Porter | 55 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.