Alert archive / Illinois / Flash Flood Warnings in 1986
Flash Flood Warning 2, NWS Chicago, IL
NWS Chicago, IL issued this flash flood warning at Sep 26, 1986, 2:40 PM CDT for Lake County, McHenry County, Illinois. It was in force for 3 hr.
The area
The counties it named.
The facts
- Issued
- Sep 26, 1986, 2:40 PM CDT (19:40 UTC)
- Expired
- Sep 26, 1986, 6:00 PM CDT
- In force
- 3 hr
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
Counties Lake County, IL, McHenry County, IL
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
The nearest sounding before it
Peoria Regional, IL (KPIA), launched 12:00Z, 7.7 hours before the alert went out and 221 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
- 1609 J/kg
- Mixed-layer CIN
- -83 J/kg
- Mixed-layer LCL
- 936 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 102 m²/s²
- 0-3 km storm-relative helicity
- 133 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.3
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KCHI 261940 FFWCHI ILC111-097-262300- BULLETIN - IMMEDIATE BROADCAST REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE CHICAGO IL 240 PM CDT FRI SEP 26 1986 THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 600 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF NORTHEAST ILLINOIS...MCHENRY AND LAKE AT 2 30 PM CDT THUNDERSTORMS CONTAINING VERY HEAVY RAIN WERE NEARLY STATIONARY FROM NEAR WAUKEGAN IN LAKE COUNTY TO ABOUT 20 MILES WEST OF WOODSTOCK IN MC HENRY COUNTY. THESE THUNDERSTORMS WILL PRODUCE FLOODING OF SMALL STREAMS AS WELL AS FLOODING OF VIADUCTS AND STREETS. AS OF 2 30 PM CDT THIS AFTERNOON ROUTE 41 WAS LIMITED TO ONE WAY TRAFFIC NEAR THE INTERSECTION OF 173 IN LAKE COUNTY..OR ABOUT 40 MILES NORTH NORTHWEST OF DOWNTOWN CHICAGO. PERSONS LIVING IN FLOOD PRONE AREAS SHOULD REMAIN ALERT FOR RISING WATERS. MOTORIST SHOULD BE ALERT FOR WATER ON THE ROADWAYS. YOU MAY REPORT ANY SEVERE WEAT7HER SUCH AS TORNADOES...DAMAGING WINDS...LARGE HAIL...OR FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY AND ASK THEM TO RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE. ATTN ISP 2 AND 15 MORRISON
What forecasters said that day
The local office's own words before this flash flood 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, Sep 26, 9:19 AM CDT, 5 hours 21 minutes before
NATIONAL WEATHER SERVICE ROCKFORD IL SPECIAL WEATHER STATEMENT 920 AM CDT FRI SEP 26 1986 ...STRONG THUNDERSTORMS MOVING OUT OF NORTHERN ILLINOIS... AT 910 AM CDT...STRONG THUNDERSTORMS WERE LOCATED OVER THE NORTHERN ILLINOIS COUNTIES OF DEKALB...BOONE...NORTHERN WINNEBAGO...AND NORTHEASTERN STEPHENSON. HEAVY RAINS...STRONG GUSTY WINDS...AND DANGEROUS LIGHTNING CAN BE EXPECTED WITH THESE STORMS. THE STORMS WERE MOVING TO THE NORTHEAST AT 35 MPH...AND SHOULD BE MOVING OUT OF THE AREA AND INTO SOUTHERN WISCONSIN AND NORTHEASTERN ILLINOIS WITHIN THE NEXT 1 TO 2 HOURS. ATTN:ISP DIST 2...16 SANDERS
Special weather statement, Sep 26, 12:28 PM CDT, 2 hours 12 minutes before
SPECIAL WEATHER AND MARINE STATEMENT NATIONAL WEATHER SERVICE CHICAGO ILLINOIS 1130 AM CDT FRI SEP 26 1986 SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS MOST OF NORTHEAST ILLINOIS LATE THIS MORNING AND WILL CONTINUE INTO THIS AFTERNOON. A FEW OF THE THUNDERSTORMS WILL BE HEAVY AND WILL PRODUCE BRIEF HEAVY DOWNPOURS OF RAIN WITH REDUCED VISIBILITY..FREQUENT LIGHTNING STRIKES AND POSSIBLY SOME ISOLATED AREAS MAY EXPERIENCE SOME HAIL. LOCAL STREET FLOODING MAY BE POSSIBLE IN PLACES. AT 1112 AM THE COOK COUNTY SHERIFF REPORTED VERY HEAVY RAIN WITH GUSTY WINDS AND SMALL PEA SIZE HAIL AT MAYWOOD 12 MILES WEST OF DOWNTOWN CHICAGO. A WEATHER OBSERVER IN DARIEN IN SOUTHWEST COOK COUNTY ESTIMATED WIND GUSTS TO 45 MPH AND VERY HEAVY RAIN. SINCE 800 AM 1.7 INCHES OF RAIN WAS REPORTED AT NAPERVILLE IN SOUTH DUPAGE COUNTY ABOUT 30 WEST SOUTHWEST OF CHICAGOS LOOP. OPERATORS OF SMALL BOATS ON LAKE MICHIGAN SHOULD MOVE TO SAFE PORT BECAUSE BZRIEF STRONG GUSTY WINDS..LIGHTNING AND LOCALLY ROUGH SEAS. THE THUNDERSTORMS WERE MOVING NORTHEAST AT 35 MPH. LEBDA
Special weather statement, Sep 26, 12:30 PM CDT, 2 hours 10 minutes before
SPECIAL WEATHER AND MARINE STATEMENT NATIONAL WEATHER SERVICE CHICAGO ILLINOIS 1130 AM CDT FRI SEP 26 1986 SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS MOST OF NORTHEAST ILLINOIS LATE THIS MORNING AND WILL CONTINUE INTO THIS AFTERNOON. A FEW OF THE THUNDERSTORMS WILL BE HEAVY AND WILL PRODUCE BRIEF HEAVY DOWNPOURS OF RAIN WITH REDUCED VISIBILITY..FREQUENT LIGHTNING STRIKES AND ISOLATED AREAS MAY EXPERIENCE SOME HAIL. LOCAL STREET FLOODING MAY BE POSSIBLE IN PLACES. AT 1112 AM THE COOK COUNTY SHERIFF REPORTED VERY HEAVY RAIN WITH GUSTY WINDS AND SMALL PEA SIZE HAIL AT MAYWOOD 12 MILES WEST OF DOWNTOWN CHICAGO. A WEATHER OBSERVER IN DARIEN IN SOUTHWEST COOK COUNTY ESTIMATED WIND GUSTS TO 45 MPH AND VERY HEAVY RAIN. SINCE 800 AM 1.7 INCHES OF RAIN WAS REPORTED AT NAPERVILLE IN SOUTH DUPAGE COUNTY ABOUT 30 WEST SOUTHWEST OF CHICAGOS LOOP. OPERATORS OF SMALL BOATS ON LAKE MICHIGAN SHOULD MOVE TO SAFE PORT BECAUSE BRIEF STRON_G GUSTY WINDS..LIGHTNING AND LOCALLY ROUGH SEAS. THE THUNDERSTORMS WERE MOVING NORTHEAST AT 35 MPH. LEBDA
Special weather statement, Sep 26, 12:35 PM CDT, 2 hours 5 minutes before
SPECIAL WEATHER AND MARINE STATEMENT NATIONAL WEATHER SERVICE CHICAGO ILLINOIS 1130 AM CDT FRI SEP 26 1986 SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS MOST OF NORTHEAST ILLINOIS LATE THIS MORNING AND WILL CONTINUE INTO THIS AFTERNOON. A FEW OF THE THUNDERSTORMS WILL BE HEAVY AND WILL PRODUCE BRIEF HEAVY DOWNPOURS OF RAIN WITH REDUCED VISIBILITY..GUSTY WINDS..FREQUENT LIGHTNING STRIKES AND ISOLATED AREAS MAY EXPERIENCE SOME HAIL. LOCAL STREET FLOODING MAY BE POSSIBLE IN PLACES. AT 1112 AM THE COOK COUNTY SHERIFF REPORTED VERY HEAVY RAIN WITH GUSTY WINDS AND SMALL PEA SIZE HAIL AT MAYWOOD 12 MILES WEST OF DOWNTOWN CHICAGO. A WEATHER OBSERVER IN DARIEN IN SOUTHWEST COOK COUNTY ESTIMATED WIND GUSTS TO 45 MPH AND VERY HEAVY RAIN. SINCE 800 AM 1.7 INCHES OF RAIN WAS REPORTED AT NAPERVILLE IN SOUTH DUPAGE COUNTY ABOUT 30 WEST SOUTHWEST OF CHICAGOS LOOP. OPERATORS OF SMALL BOATS ON LAKE MICHIGAN SHOULD MOVE TO SAFE PORT BECAUSE BRaIEF STRONG GUSTY WINDS..LIGHTNING AND LOCALLY ROUGH SEAS. THE THUNDERSTORMS WERE MOVING NORTHEAST AT 35 MPH. LEBDA
Special weather statement, Sep 26, 12:55 PM CDT, 1 hour 45 minutes before
SPECIAL WEATHER AND MARINE STATEMENT...CORRECTION ADD 1 HOUR TO TIMES.. NATIONAL WEATHER SERVICE CHICAGO ILLINOIS 1230 AM CDT FRI SEP 26 1986 SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS MOST OF NORTHEAST ILLINOIS LATE THIS MORNING AND WILL CONTINUE INTO THIS AFTERNOON. A FEW OF THE THUNDERSTORMS WILL BE HEAVY AND WILL PRODUCE BRIEF HEAVY DOWNPOURS OF RAIN WITH REDUCED VISIBILITY..GUSTY WINDS..FREQUENT LIGHTNING STRIKES AND ISOLATED AREAS MAY EXPERIENCE SOME HAIL. LOCAL STREET FLOODING MAY BE POSSIBLE IN PLACES. AT 1212 AM THE COOK COUNTY SHERIFF REPORTED VERY HEAVY RAIN WITH GUSTY WINDS AND SMALL PEA SIZE HAIL AT MAYWOOD 12 MILES WEST OF DOWNTOWN CHICAGO. A WEATHER OBSERVER IN DARIEN IN SOUTHWEST COOK COUNTY ESTIMATED WIND GUSTS TO 45 MPH AND VERY HEAVY RAIN. SINCE 800 AM 1.7 INCHES OF RAIN WAS REPORTED AT NAPERVILLE IN SOUTH DUPAGE COUNTY ABOUT 30 WEST SOUTHWEST OF CHICAGOS LOOP. OPERATORS OF SMALL BOATS ON LAKE MICHIGAN SHOULD MOVE TO SAFE PORT BECAUSE BRIEF STRONG GUSTY WINDS..LIGHTNING AND LOCALLY ROUGH SEAS. THE THUNDERSTORMS WERE MOVING NORTHEAST AT 35 MPH. LEBDA
Special weather statement, Sep 26, 1:08 PM CDT, 1 hour 32 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHICAGO ILLINOIS 1 05 PM CDT FRI SEP 26 1986 ...STRONG THUNDERSTORMS CONTINUE TO DEVELOP ACROSS MUCH OF CENTRAL AND NORTHEAST ILLINOIS THIS EARLY AFTERNOON.... AT 1 PM CDT THIS AFTERNOON THE STRONGEST THUNDERSTORM ACTIVITY WAS LOCATED IN A LINE FROM THE SOUTHERN PORTION OF THE CHICAGO METROPOLITAN AREA..OVER SOUTHERN COOK COUNTY...AND EXTENDED SOUTH SOUTHWESTWARD NEAR KANKAKEE TO WESTERN IROQUOIS COUUNTY..OR JUST WEST OF WATSEKA. MOVEMENT OF THIS LINE WAS EASTWARD AT 30 MPH. VERY HEAVY DOWNPOURS OF RAIN HAS BEEN REPORTED IN THIS LINE ALONG WITH GUSTY WINDS OF 40 TO 45 MPH AND HAIL. AT 1 PM THIS AFTERNOON GOLF BALL SIZED HAIL WAS REPORTED ABOUT 20 MILES EAST OF PONTIAC. MORRISON
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 26, 1:19 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Will | 31 min |
| Sep 26, 1:19 PM CDT | Severe Thunderstorm Warning | LOT | Kankakee | 31 min |
Nearby
Flash Flood Warnings in Illinois, 1986Every flash flood warning in 1986
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.