Alert archive / Illinois / Flash Flood Warnings in 1986
Flash Flood Warning 1, NWS Lincoln, IL
NWS Lincoln, IL issued this flash flood warning at Sep 20, 1986, 12:33 AM CDT for DeWitt County, Logan County, Illinois. It was in force for 5 hr.
The area
The counties it named.
The facts
- Issued
- Sep 20, 1986, 12:33 AM CDT (05:33 UTC)
- Expired
- Sep 20, 1986, 6:00 AM CDT
- In force
- 5 hr
- Issued by
- NWS Lincoln, IL
- Area
- Whole counties
Counties DeWitt County, IL, Logan 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 00:00Z, 5.6 hours before the alert went out and 70 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
- 1948 J/kg
- Mixed-layer CIN
- -53 J/kg
- Mixed-layer LCL
- 878 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 316 m²/s²
- 0-3 km storm-relative helicity
- 450 m²/s²
- Significant tornado parameter
- 4.6
- Supercell composite
- 34.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KSPI 200533 FFWSPI ILC107-039-201100- BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE SPRINGFIELD IL 1233 AM CDT SAT SEP 20 1986 THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 600 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF CENTRAL ILLINOIS...LOGAN AND DE-WITT AT 12 25 AM CDT EMERGENCY SERVICE AND DISASTER AGENCY REPORT FLOODING IN MUCH OF DE-WITT COUNTY WHE'RE IN EXCESS OF 4 INCHES OF RAIN HAS ALREADY FALLEN AND STILL RAINING MODERATE TO HEAVY AT TIMES..REPORTS FROM STATE POLICE IN LOGAN COUNTY HAS FLOODING OF STREETS..LOW LYING AREAS AND SMALL STREAMS. ATTN ISP DIST...6 AND 9 HILLIARD
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 19, 10:08 PM CDT, 2 hours 25 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PEORIA IL 10 PM CDT FRI SEP 19 1986 THE SEVERE THUNDERSTORM WARNING FOR MCLEAN COUNTY EXPIRED AT 10 PM. NO FURTHER REPORTS HAVE BEEN RECEIVED OF STORMS NEAR SEVERE INTENSITY. THUNDERSTORMS EXTEND IN A LINE ACROSS ILLINOIS FROM BURLINGTON IOWA THROUGH PEORIA AND BLOOMINGTON TO WEST CENTRAL INDIANA. THE STORMS DEVELOP AND MOVE EAST ALONG THE LINE, CONTINUING TO POUR HEAVY RAIN ON THE AREA. THIS GIVES THE POTENTIAL FOR HEAVY RAINFALL AMOUNTS AND POSSIBLE FLOODING ACROSS THE AREA TONIGHT. AN ADDITIONAL 0.75 INCH OF RAIN HAS FALLEN AT THE AIRPORT THIS EVENING... MAKING THE TOTAL 1.66 INCHES FOR THE DAY... UP UNTIL 10 PM. STARK
Special weather statement, Sep 19, 10:16 PM CDT, 2 hours 17 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPRINGFIELD IL
1010 PM CDT FRI SEP 19 1986
...HEAVY THUNDERSTORMS ENTERING NORTHERN PIATT AND NORTHWESTERN
CHAMPAIGN COUNTIES...
AT 1010 PM CDT THE SOUTHERN EDGE OF AN AVERAGE 30 MILE WIDE AREA OF
RAINSHOWERS AND THUNDERSTORMS EXTENDED FROM THE INDIANA BORDER...JUST [
NORTH OF DANVILLE TO THE CHAMPAIGN AREA TO 20 MILES SOUTH OF BLOOMING-
TON.
THUNDERSTORMS PRODUCING HEAVY RAIN...GUSTY WINDS...AND SMALL HAIL WERE
JUST ENTERING NORTHWEST CHAMPAIGN COUNTY AND NORTHERN PIATT COUNTY.
MOVEMENT WAS TOWARD THE EAST AND SOUTHEAST AT 20 TO 25 MPH.
PERSONS IN THE AFFECTED AREAS SHOULD BE ON THE ALERT FOR WEATHER
DEVELOPMENTS.
FSSpecial weather statement, Sep 20, 12:06 AM CDT, 27 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SPRINGFIELD IL 1205 AM CDT SAT SEP 20 1986 ...HEAVY THUNDERSTORMS ENTERING NORTHERN SANGAMON COUNTY... ...SOME FLOODING IN LOGAN AND DE WITT COUNTIES... AT 1205 AM CDT THE SOUTHERN EDGE OF AN AVERAGE 30 MILE WIDE AREA OF RAINSHOWERS AND THUNDERSTORMS EXTENDED 20 MILES NORTHWEST OF SPRINGFIELD [ TO 10 MILES NORTH AND NORTHEAST OF SPRINGFIELD AND ON TO DECATUR AND 20 MILES SOUTH OF CHAMPAIGN. THUNDERSTORMS PRODUCING HEAVY RAIN...GUSTY WINDS...AND SMALL HAIL WERE REPORTED WITH THIS WEATHER SYSTEM. MOVEMENT HAS TURNED TOWARD THE SOUTHEAST AND SOUTH AT 15 TO 20 MPH TOWARD MACON AND SANGAMON COUNTIES. SOME LOCAL FLOODING OF STREETS...LOW LYING AREAS AND VIADUCTS HAS BEEN REPORTED IN LOGAN AND DE WITT COUNTIES. PERSONS IN THE AFFECTED AREAS SHOULD BE ALERT TO DEVELOPING WEATHER CONDITIONS. FS
The office that day
Everything else NWS Lincoln, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 19, 9:02 PM CDT | Severe Thunderstorm Warning | ILX | McLean | 58 min |
| Sep 20, 2:46 AM CDT | Flash Flood Warning | ILX | Sangamon | 4 hr |
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.