Alert archive / Illinois / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 7, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Apr 5, 1997, 4:59 PM CST for 5 counties in Illinois. It was in force for 31 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
- Apr 5, 1997, 4:59 PM CST (22:59 UTC)
- Expired
- Apr 5, 1997, 5:30 PM CST
- In force
- 31 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
Counties Boone County, IL, DeKalb County, IL, Kane County, IL, Kendall County, IL, McHenry County, IL
The radar
The Chicago radar (KLOT), 61 km from the middle of the area, began a volume at 23:00 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 |
|---|---|---|---|
| Apr 5, 5:00 PM CST | Thunderstorm Wind 52 | Burlington, IL | |
| Apr 5, 5:05 PM CST | Thunderstorm Wind 54 | Nrn Part Of Cnty, 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 |
|---|---|---|---|
| Apr 5, 4:15 PM CST | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 11.0 hours before the alert went out and 165 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
- 515 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 94 m²/s²
- 0-3 km storm-relative helicity
- 99 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.
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, Apr 5, 11:16 AM CST, 5 hours 43 minutes before
ILZ003>006-008-010>014-019>023-032-033-039-520>523-INZ001>005- 010>016-019-020-520>522-LMZ530-061000- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO IL 1108 AM CST (1208 PM EST) SAT APR 5 1997 FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST AND NORTH CENTRAL INDIANA THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA THIS AFTERNOON AND CONTINUE INTO THIS EVENING. HOWEVER THE THUNDERSTORMS ARE NOT EXPECTED TO BECOME SEVERE. A WEAK COLD FRONT IS EXPECTED TO SWEEP THROUGH THE AREA THIS EVENING BRINGING THE THREAT OF THUNDERSTORMS TO THE AREA. CONSIDERABLE CLOUDINESS AHEAD OF THE FRONT SHOULD INHIBIT HEATING THIS AFTERNOON SO THE THUNDERSTORMS SHOULD REMAIN BELOW THE SEVERE CATERGORY IN SPITE OF ABUNDANT GULF MOISTURE AND A VIGOROUS UPPER LEVEL DISTURBANCE MOVING THROUGH THE AREA. ALM
Special weather statement, Apr 5, 2:10 PM CST, 2 hours 49 minutes before
ILZ003>006-008-010>014-019>023-032-033-039-520>523-INZ001>005- 010>016-019-020-520>522-LMZ530-061000- HAZARDOUS WEATHER OUTLOOK/UPDATED NATIONAL WEATHER SERVICE CHICAGO IL 2 10 PM CST (1208 PM EST) SAT APR 5 1997 FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST AND NORTH CENTRAL INDIANA ...SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA THIS EVENING... A WEAK COLD FRONT IS EXPECTED TO SWEEP THROUGH THE AREA THIS EVENING BRINGING THE THREAT OF SEVERE THUNDERSTORMS TO THE AREA. AT 2 PM CST THIS AFTERNOON A LINE OF SEVERE THUNDERSTORMS HAD DEVELOPED IN EXTREME WEST CENTRAL ILLINOIS NEAR THE MISSISSIPPI RIVER AND EXTENDED SOUTHWARD TO NEAR ST LOUIS. THIS BAND OF THUNDERSTORMS WERE MOVING NORTHEAST AROUND 40 MPH AND SHOULD MOVE INTO NORTHEAST AND NORTH CENTAL ILLINOIS EARLY THIS EVENING THEN INTO NORTHWEST AND NORTH CENTRAL INDIANA LATER THIS EVENING. ALM
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 5, 3:45 PM CST | Severe Thunderstorm Warning | LOT | LaSalle, Lee, Livingston | 45 min |
| Apr 5, 3:45 PM CST | Severe Thunderstorm Warning | LOT | Ogle | 45 min |
| Apr 5, 4:26 PM CST | Severe Thunderstorm Warning | LOT | DeKalb, Grundy, Kendall, LaSalle | 34 min |
| Apr 5, 4:26 PM CST | Severe Thunderstorm Warning | LOT | Ford, Livingston | 34 min |
| Apr 5, 4:26 PM CST | Severe Thunderstorm Warning | LOT | Lee | 34 min |
| Apr 5, 4:59 PM CST | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Kankakee | 31 min |
| Apr 5, 4:59 PM CST | Severe Thunderstorm Warning | LOT | Grundy, Will | 31 min |
| Apr 5, 4:59 PM CST | Severe Thunderstorm Warning | LOT | DuPage | 31 min |
| Apr 5, 5:26 PM CST | Severe Thunderstorm Warning | LOT | Cook, Lake, McHenry | 34 min |
| Apr 5, 5:26 PM CST | Severe Thunderstorm Warning | LOT | DuPage, Kankakee, Will | 34 min |
| Apr 5, 5:26 PM CST | Severe Thunderstorm Warning | LOT | Iroquois | 34 min |
| Apr 5, 5:57 PM CST | Severe Thunderstorm Warning | LOT | Lake, Porter | 33 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.