Alert archive / Illinois / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 20, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Jun 30, 1990, 3:01 PM CDT for Cook County, DuPage County, Illinois. It was in force for 59 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
- Jun 30, 1990, 3:01 PM CDT (20:01 UTC)
- Expired
- Jun 30, 1990, 4:00 PM CDT
- In force
- 59 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
Counties Cook County, IL, DuPage County, IL
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 30, 3:05 PM CDT | Hail 0.75 | Cook, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Green Bay/Straub, WI (KGRB), launched 12:00Z, 8.0 hours before the alert went out and 290 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
- 138 J/kg
- Mixed-layer CIN
- -220 J/kg
- Mixed-layer LCL
- 1486 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 114 m²/s²
- 0-3 km storm-relative helicity
- 95 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 5:44 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Will | 61 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 1990Every severe thunderstorm warning in 1990
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.