Alert archive / Illinois / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 50, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at May 18, 1997, 7:42 PM CDT for Kendall County, LaSalle County, Illinois. It was in force for 63 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
- May 18, 1997, 7:42 PM CDT (00:42 UTC)
- Expired
- May 18, 1997, 8:45 PM CDT
- In force
- 63 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
Counties Kendall County, IL, LaSalle County, IL
The radar
The Chicago radar (KLOT), 50 km from the middle of the area, began a volume at 00:45 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 |
|---|---|---|---|
| May 18, 7:45 PM CDT | Thunderstorm Wind 50 | Yorkville, IL | Thunderstorm winds caused damage at a farm southeast of Yorkville. A semi-trailer was blown over, windows were broken and shingles peeled off a barn, and trees and limbs were blown down. |
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 |
|---|---|---|---|
| May 18, 5:30 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 0.7 hours before the alert went out and 147 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
- 1314 J/kg
- Mixed-layer CIN
- -31 J/kg
- Mixed-layer LCL
- 1926 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 104 m²/s²
- 0-3 km storm-relative helicity
- 292 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 8.8
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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.
In the hours before
Special weather statement, May 18, 1:48 PM CDT, 5 hours 54 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001>005-010>016-019>020- 191000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHICAGO IL 1 45 PM CDT SUN MAY 18 1997 SEVERE THUNDERSTORM WATCH NUMBER 294 IS NO LONGER IN EFFECT FOR LAKE...PORTER...JASPER...NEWTON AND BENTON COUNTIES IN EXTREME NORTHWEST INDIANA. ALTHOUGH SCATTERED THUNDERSTORMS ARE STILL OCCURRING IN THIS AREA THEY ARE NO LONGER EXPECTED TO BE SEVERE. HOWEVER THERE IS STILL A CHANCE OF SEVERE THUNDERSTORMS THIS EVENING OR EARLY TONIGHT AS A COOL FRONT APPROACHES THE AREA FROM THE NORTHWEST. MORRISON
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 18, 7:00 PM CDT | Tornado Warning | LOT | Lake, McHenry | 60 min |
| May 18, 7:09 PM CDT | Severe Thunderstorm Warning | LOT | Kane | 66 min |
| May 18, 7:19 PM CDT | Severe Thunderstorm Warning | LOT | LaSalle, Lee | 56 min |
| May 18, 7:30 PM CDT | Tornado Warning | LOT | Kane | 30 min |
| May 18, 7:47 PM CDT | Tornado Warning | LOT | DuPage, Will | 58 min |
| May 18, 8:04 PM CDT | Tornado Warning | LOT | Grundy, Kankakee, Will | 56 min |
| May 18, 8:04 PM CDT | Tornado Warning | LOT | Cook | 56 min |
| May 18, 8:52 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Kankakee | 2 hr |
| May 18, 8:52 PM CDT | Severe Thunderstorm Warning | LOT | Livingston | 2 hr |
| May 18, 9:18 PM CDT | Tornado Warning | LOT | LaSalle | 57 min |
| May 18, 9:54 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, Livingston | 66 min |
| May 18, 10:50 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois, Kankakee | 55 min |
| May 18, 11:12 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Livingston | 63 min |
| May 18, 8:15 PM CDT | Tornado Warning | LOT | Lake, Porter | 60 min |
| May 18, 8:52 PM CDT | Severe Thunderstorm Warning | LOT | Jasper, LaPorte, Pulaski, Starke, White | 2 hr |
| May 18, 8:52 PM CDT | Severe Thunderstorm Warning | LOT | Marshall, Saint Joseph | 2 hr |
| May 18, 9:19 PM CDT | Severe Thunderstorm Warning | LOT | Fulton, Kosciusko | 56 min |
| May 18, 9:19 PM CDT | Severe Thunderstorm Warning | LOT | Elkhart | 56 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 1997Every severe thunderstorm warning in 1997
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.