Alert archive / Illinois / Flash Flood Warnings in 1986

Flash Flood Warning 7, NWS Quad Cities, IA

July 10, 1986Mercer County, Illinois

NWS Quad Cities, IA issued this flash flood warning at Jul 10, 1986, 9:30 PM CDT for Mercer County, Illinois. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Jul 10, 1986, 9:30 PM CDT (02:30 UTC)
Expired
Jul 10, 1986, 10:30 PM CDT
In force
60 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Mercer 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

Salem-Leckrone, IL (KSLO), launched 00:00Z, 2.5 hours before the alert went out and 325 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.

Skew-T log-pSkew-T log-p diagram, Salem-Leckrone, IL at 00:00Z on 1986-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 933 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salem-Leckrone, IL at 00:00Z on 1986-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
933 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1223 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KMLI 110230
FFWMLI
IAC163-139-ILC161-131-073-195-110500-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOLINE IL
930 PM CDT THU JUL 10 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING 
EFFECTIVE UNTIL 1200 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

EXTREME EAST IOWA...SCOTT AND EASTERN MUSCATINE
NORTHWEST ILLINOIS...ROCK-ISLAND...MERCER...HENRY AND SOUTHERN 
 WHITESIDE

SLOW MOVING STRONG THUNDERSTORMS AND VERY HEAVY RAIN ALONG
WITH SATURATED GROUND CONDITIONS HAVE COMBINED TO PRODUCE
EXTENSIVE LOWLAND AND URBAN FLOODING IN THESE AREAS.

ADDITIONAL HEAVY RAIN WAS MOVING INTO THESE AREAS AND WILL
LIKELY EXCEED TWO INCHES IN LOCALIZED AREAS..ENOUGH TO CAUSE
FLASH FLOODING UNDER THESE CONDITIONS.

 FLASH FLOOD WARNING MEANS FLASH FLOODING IS OCCURRING OR IS
 IMMINENT IN THE SPECIFIED AREA.

 DO NOT TRY TO DRIVE THROUGH FLOODED AREAS.

 PERSONS ALONG OR NEAR STREAMS SUBJECT TO FLASH FLOODING SHOULD
 BE PREPARED TO MOVE TO A PLACE OF SAFETY IMMEDIATELY.

 ATTN ISP 7 AND 1.

WIGGINS/FOBERT

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, Jul 10, 5:06 PM CDT, 4 hours 24 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOLINE IL
505 PM CDT THU JUL 10 1986

...SHOWERS AND THUNDERSTORMS MOVING INTO EASTERN IOWA...

AT 5 PM CDT..RADAR SHOWED SCATTERED SHOWERS DEVELOPING ATND
MOVING INTO EASTERN IOWA.

THE STRONGEST WAS SOUTHWEST OF IOWA CITY  AND ANOTHER STRONG
ONE WAS IN EXTREME SOUTHEAST IOWA NEAR KEOSAUQUA.

SHOWERS AND THUNDERSTORMS WERE MOVING MAINLY EAST ABOUT 35 MPH.

WIGGINS
Special weather statement, Jul 10, 7:39 PM CDT, 1 hour 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOLINE IL
740 PM CDT THU JUL 10 1986

...STRONG THUNDERSTORMS APPROACHING EXTREME SOUTHEAST IOWA...

AT 730PM CDT..RADAR SHOWED STRONG THUNDERSTORMS LOCATED OVER
NORTHEAST MISSOURI BETWEEN KIRKSVILLE MISSOURI AND QUINCY
ILLINOIS. KIRKSVILLE REPORTED WIND GUSTS UP TO 48 MPH SHORTLY
BEFORE 7PM AND QUINCY REPORTED GUSTS OVER 60 MPH AROUND 7PM.

THESE STORMS WERE MOVING TO THE EAST NORTHEAST AT 30 MILES AN HOUR
AND WILL PASS OVER PARTS OF SOUTHERN LEE COUNTY IOWA BETWEEN 745 AND
845 PM.

STRONG GUSTY WINDS..HAIL AND VERY HEAVY RAIN ARE POSSIBLE WITH THESE
STORMS. PERSONS SHOULD MONITOR RADIO AND TV AND LISTEN FOR FURTHER
STATEME#NTS OR WARNINGS AND BE PREPARED TO SEEK SHELTER IF SEVERE
WEATHER OCCURS.
FOBERT

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 10, 9:30 PM CDTFlash Flood WarningDVNHenry, Rock Island, Whiteside60 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.