Alert archive / Illinois / Tornado Warnings in 1998
Tornado Warning 7, NWS Chicago, IL
NWS Chicago, IL issued this tornado warning at Jun 18, 1998, 6:45 PM CDT for Lee County, Illinois. It was in force for 30 min. 2 reports 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
- Jun 18, 1998, 6:45 PM CDT (23:45 UTC)
- Expired
- Jun 18, 1998, 7:15 PM CDT
- In force
- 30 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
County Lee County, IL
The radar
The Chicago radar (KLOT), 102 km from the middle of the area, began a volume at 23:34 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 |
|---|---|---|---|
| Jun 18, 6:55 PM CDT | Tornado F0 | Nelson, IL | |
| Jun 18, 6:55 PM CDT | Thunderstorm Wind 50 | Dixon, 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 18, 4:00 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 11.8 hours before the alert went out and 101 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
- 2000 J/kg
- Mixed-layer CIN
- -220 J/kg
- Mixed-layer LCL
- 1205 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 112 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
373 WFUS1 KCHI 182344 RRA TORCHI ILC103-190015- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE CHICAGO IL 645 PM CDT THU JUN 18 1998 THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A * TORNADO WARNING FOR... LEE COUNTY IN NORTH CENTRAL ILLINOIS * UNTIL 715 PM CDT * AT 645PM CDT A TORNADO WAS REPORTED ON THE GROUND NEAR WHITESIDE COUNTY AIRPORT NEAR STERLING. IT IS MOVING NORTHEAST ABOUT 25 MPH * THE TORNADO WILL BE NEAR... NELSON DIXON ALONG I-88 GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR $$ SOMREK
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 3:23 PM CDT | Severe Thunderstorm Warning | LOT | Boone, DeKalb, Ogle, Winnebago | 62 min |
| Jun 18, 6:10 PM CDT | Severe Thunderstorm Warning | LOT | Ogle, Winnebago | 65 min |
| Jun 18, 6:10 PM CDT | Severe Thunderstorm Warning | LOT | Lee | 65 min |
Nearby
Tornado Warnings in Illinois, 1998Every tornado warning in 1998Tornadoes in 1998
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.