Alert archive / Illinois / Tornado Warnings in 1991
Tornado Warning 7, NWS Chicago, IL
NWS Chicago, IL issued this tornado warning at Mar 27, 1991, 4:07 PM CST for Cook County, Illinois. It was in force for 28 min. 3 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
- Mar 27, 1991, 4:07 PM CST (22:07 UTC)
- Expired
- Mar 27, 1991, 4:35 PM CST
- In force
- 28 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
County Cook County, IL
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Mar 27, 4:07 PM CST | Tornado F3 | Cook, IL | |
| Mar 27, 4:13 PM CST | Hail 1 | Cook, IL | |
| Mar 27, 4:30 PM CST | Thunderstorm Wind 0 | 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, 10.1 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1516 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 59 m²/s²
- 0-3 km storm-relative helicity
- -11 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 |
|---|---|---|---|---|
| Mar 26, 11:48 PM CST | Severe Thunderstorm Warning | LOT | Grundy, LaSalle | 42 min |
| Mar 26, 11:48 PM CST | Severe Thunderstorm Warning | LOT | Livingston | 57 min |
| Mar 26, 11:48 PM CST | Severe Thunderstorm Warning | LOT | Will | 57 min |
| Mar 27, 1:00 AM CST | Severe Thunderstorm Warning | LOT | Grundy, LaSalle, Livingston | 60 min |
| Mar 27, 2:17 AM CST | Severe Thunderstorm Warning | LOT | Cook, Will | 43 min |
| Mar 27, 7:41 AM CST | Severe Thunderstorm Warning | LOT | Cook, Lake | 34 min |
| Mar 27, 7:45 AM CST | Tornado Warning | LOT | Cook, Lake | 30 min |
| Mar 27, 2:13 PM CST | Severe Thunderstorm Warning | LOT | McHenry | 62 min |
| Mar 27, 2:32 PM CST | Tornado Warning | LOT | LaSalle | 28 min |
| Mar 27, 3:00 PM CST | Tornado Warning | LOT | Grundy, Kendall, LaSalle | 45 min |
| Mar 27, 3:04 PM CST | Severe Thunderstorm Warning | LOT | Lake | 26 min |
| Mar 27, 3:23 PM CST | Severe Thunderstorm Warning | LOT | Cook, Lake | 52 min |
| Mar 27, 3:33 PM CST | Tornado Warning | LOT | DuPage, Will | 42 min |
| Mar 27, 3:53 PM CST | Tornado Warning | LOT | Grundy, Kendall, LaSalle | 52 min |
| Mar 27, 4:09 PM CST | Tornado Warning | LOT | Kankakee, Will | 36 min |
| Mar 27, 4:44 PM CST | Tornado Warning | LOT | Lake, Porter | 31 min |
Nearby
Tornado Warnings in Illinois, 1991Every tornado warning in 1991Tornadoes in 1991
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.