Alert archive / Illinois / Severe Thunderstorm Warnings in 2002
Severe Thunderstorm Warning 26, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Jul 8, 2002, 8:23 PM CDT for Lee County, Ogle County, Illinois. It was in force for 37 min. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Jul 8, 2002, 8:23 PM CDT (01:23 UTC)
- Expired
- Jul 8, 2002, 9:00 PM CDT
- In force
- 37 min
- Issued by
- NWS Chicago, IL
- Area
- Counties, with a storm outline in the text
Counties Lee County, IL, Ogle County, IL
The radar
The Chicago radar (KLOT), 107 km from the middle of the area, began a volume at 01:24 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 was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 8, 8:40 PM CDT | Thunderstorm Wind 57 E | Polo, IL |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 1.4 hours before the alert went out and 103 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
- 2747 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 1414 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 103 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.1
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 8, 2:15 PM CDT, 6 hours 8 minutes earlier.
Area forecast discussion, Jul 8, 2:15 PM CDT, 6 hours 8 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 215 PM CDT MON JUL 8 2002 MODELS MAY BE A LITTLE FASTER ON MOVING SYSTEMS THAN LAST 6 HRS LOOPING WOULD INDICATE. CONVECTIVE TEMP TDA ARND 91 WHICH IS ABT WHERE TEMPS ARE NOW...BUT 18Z DVN SOUNDING INDICATING SOME SMALL CAPS AT 900 AND 770 MB AND SMALL LAPSE RATE ABOVE THE TOP INVERSION. SO THINGS NOT FIRING YET ACROSS IA OR IL. MCS OVER NRN WI THIS AM NOW WEAKENED AND DRIFTING ESE INTO CENTRAL LWR MICH. MAIN COLD FRONT OUT IN NWRN IA YET. LINEAR ADVECTION WUD SUGGEST IT APPROACHING DBQ AT 06Z WHICH WUD APPROX ETA BETTER THAN AVN. BELIEVE TSTMS LIKELY TO BLOW UP LT TNGT ALG FNT. STILL WILL PLACE FROPA THRU RFD SHRTLY AFT SUNUP...THEN THRU CHI LT MRNG...THRU REST OF CWA BY 2 OR 3 PM. STRENGTH OF PUSH WUD SUGGEST GOOD CAA HIGHLIGHTING THE LOW POST-FNTL SC IN SRN MN. WILL BE LT MRNG TO ERY AFTN CLRG OF THIS SC AT RFD BUT LT AFTN OR ERY EVE FOR SRN CWA. COOL NE WNDS OFF LK MICH SHUD BRING REFRESHING TEMPS IN MID 70S TO MOST OF NERN IL/NWRN IN WED-FRI. TAKING OUT PCPN FOR FRI AS PER LATEST MRF. GOING DRY WITH SOME TEMP RECOVERY TO MID 80S SAT THRU MON. .CHI...NONE BRUMER
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 8, 10:13 PM CDT | Special Marine Warning | LOT | 92 min | |
| Jul 8, 10:13 PM CDT | Special Marine Warning | LOT | 92 min | |
| Jul 9, 2:28 AM CDT | Flash Flood Warning | LOT | Cook, DuPage, Kane | 2 hr |
Nearby
Severe Thunderstorm Warnings in Illinois, 2002Every severe thunderstorm warning in 2002
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.