Alert archive / Illinois / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 13, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at May 6, 1998, 2:55 PM CDT for Cook County, DuPage County, Will County, Illinois. It was in force for 15 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- May 6, 1998, 2:55 PM CDT (19:55 UTC)
- Expired
- May 6, 1998, 3:10 PM CDT
- In force
- 15 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
Counties Cook County, IL, DuPage County, IL, Will County, IL
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 7.9 hours before the alert went out and 185 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
- 23 J/kg
- Mixed-layer CIN
- -112 J/kg
- Mixed-layer LCL
- 1434 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 2 m²/s²
- 0-3 km storm-relative helicity
- -2 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, May 6, 10:37 AM CDT, 4 hours 18 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001>002-010>011-019- 071100- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO IL 1100 AM CDT/EST WED MAY 6 1998 FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST INDIANA NO SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE AREA THIS AFTERNOON OR TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AGAIN THIS AFTERNOON. MORE CONCENTRATED AREAS OF THUNDERSTORMS WILL PERSIST TO THE WEST AND SOUTH OF THE REGION. THE RISK OF STRONGER THUNDERSTORMS WILL REMAIN TO THE SOUTH OF THE ROCKFORD...CHICAGO AND GARY AREAS...FROM LIVINGSTON AND FORD COUNTIES...EASTWARD INTO NORTHWEST INDIANA...GENERALLY SOUTH OF THE KANKAKEE RIVER. MERZLOCK
Special weather statement, May 6, 1:13 PM CDT, 1 hour 42 minutes before
ILZ019>023-061857- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHICAGO IL 113 PM CDT WED MAY 6 1998 ...FUNNEL CLOUDS REPORTED... RADAR INDICATES AN AREA OF SCATTERED THUNDERSTORMS DEVELOPING QUICKLY OVER PORTIONS OF NORTHEAST ILLINOIS. THE STRONGEST STORMS HAVE MOVED INTO SOUTHERN GRUNDY COUNTY NEAR MAZON...OR ABOUT 10 MILES SOUTH OF MORRIS. A FUNNEL CLOUD WAS SIGHTED AS THIS STORM MOVED THROUGH THE DWIGHT AREA. THIS THUNDERSTORM WAS MOVING NORTH AT ABOUT 20 MPH AND WILL BE PASSING THROUGH GRUNDY AND EXTREME EASTERN LA SALLE COUNTY BY 130 PM CDT. VERY HEAVY RAIN AND SOME HAIL CAN BE EXPECTED. ELSEWHERE...SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP DURING THE AFTERNOON. ALTHOUGH SOME OF THE MORE RAPIDLY DEVELOPING STORM CELLS MAY BRIEFLY PRODUCE A FUNNEL CLOUD...ATMOSPHERIC CONDITIONS DO NOT FAVOR TORNADO DEVELOPMENT. PERSONS IN NORTHERN ILLINOIS SHOULD NOT BE UNDULY ALARMED...BUT SHOULD BE ON THE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS AND SHOULD BE PREPARED TO SEEK SAFETY IF THREATENING WEATHER DEVELOPS. MERZLOCK
Special weather statement, May 6, 1:13 PM CDT, 1 hour 42 minutes before
ILZ019>023-061857- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHICAGO IL 113 PM CDT WED MAY 6 1998 ...FUNNEL CLOUDS REPORTED... RADAR INDICATES AN AREA OF SCATTERED THUNDERSTORMS DEVELOPING QUICKLY OVER PORTIONS OF NORTHEAST ILLINOIS. THE STRONGEST STORMS HAVE MOVED INTO SOUTHERN GRUNDY COUNTY NEAR MAZON...OR ABOUT 10 MILES SOUTH OF MORRIS. A FUNNEL CLOUD WAS SIGHTED AS THIS STORM MOVED THROUGH THE DWIGHT AREA. THIS THUNDERSTORM WAS MOVING NORTH AT ABOUT 20 MPH AND WILL BE PASSING THROUGH GRUNDY AND EXTREME EASTERN LA SALLE COUNTY BY 130 PM CDT. VERY HEAVY RAIN AND SOME HAIL CAN BE EXPECTED. ELSEWHERE...SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP DURING THE AFTERNOON. ALTHOUGH SOME OF THE MORE RAPIDLY DEVELOPING STORM CELLS MAY BRIEFLY PRODUCE A FUNNEL CLOUD...ATMOSPHERIC CONDITIONS DO NOT FAVOR TORNADO DEVELOPMENT. PERSONS IN NORTHERN ILLINOIS SHOULD NOT BE UNDULY ALARMED...BUT SHOULD BE ON THE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS AND SHOULD BE PREPARED TO SEEK SAFETY IF THREATENING WEATHER DEVELOPS. MERZLOCK
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 6, 1:48 PM CDT | Flash Flood Warning | LOT | Grundy, Will | 6 hr |
| May 6, 1:48 PM CDT | Flash Flood Warning | LOT | Cook | 6 hr |
| May 6, 1:53 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Will | 37 min |
| May 6, 1:53 PM CDT | Severe Thunderstorm Warning | LOT | Kendall | 37 min |
| May 6, 2:40 PM CDT | Flash Flood Warning | LOT | Cook, DuPage, Will | 30 min |
| May 6, 2:40 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Will | 30 min |
| May 6, 2:55 PM CDT | Flash Flood Warning | LOT | Cook, DuPage, Will | 15 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 1998Every severe thunderstorm warning 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; the sounding from the Mesonet's radiosonde archive.