Alert archive / Iowa / Flash Flood Warnings in 1986

Flash Flood Warning 5, NWS Des Moines, IA

August 13, 1986Clarke County, Decatur County, Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 13, 1986, 9:28 AM CDT for Clarke County, Decatur County, Iowa. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Aug 13, 1986, 9:28 AM CDT (14:28 UTC)
Expired
Aug 13, 1986, 12:00 PM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Clarke County, IA, Decatur County, IA

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

Omaha, NE (KOAX), launched 12:00Z, 2.5 hours before the alert went out and 222 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, Omaha, NE at 12:00Z on 1986-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 1986-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 432 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3647 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
432 m²/s²
0-3 km storm-relative helicity
548 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 KDSM 131430
FFWDSM
IAC039-053-131700-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
928 AM CDT WED AUG 13 1986

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

SOUTH CENTRAL IOWA...SOUTHERN CLARKE AND DECATUR

A FLASH FLOOD WARNING MEANS FLOODING IS IMINENT OR IS OCCURRING.
TAKE NECESSARY PRECAUTIONS IMMEDIATELY.

THIS WARNING INCLUDES THE CITIES GRAND RIVER..VANWART AND LEON..
ALL APPROXMITELY 55 MILES TO THE SOUTH OF DES MOINES.

VERY HEAVY RAINS OF 2.5 TO OVER 5 INCHES FELL IN THIS AREA
BETWEEN 3 AM AND 9 AM THIS MORNING.  THESE HEAVY RAINS WILL
CAUSE MANY CREEKS TO FLOW OVER THEIR BANKS.

AT 915 AM A COUNTY ROAD 7 MILES TO THE NORTHWEST OF GRAND
RIVER WAS WASHED OUT.

PEOPLE LIVING IN FLOOD PRONE AREAS SHOULD MOVE TO HIGHER GROUND
AT ONCE.  ACT QUICKLY..AS FLOOD WATERS OFTEN RISE VERY QUICKLY.

IF YOU ARE DRIVING..DO NOT TRY TO DRIVE THROUGH FLOOD WATERS OF
UNKNOWN DEPTH.  IF YOUR VEHICLE STALLS..ABANDON IT IMMEDIATELY
AND SEEK HIGHER GROUND.

WEINBRECHT

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 13, 12:13 PM CDTFlash Flood WarningDMXDallas, Polk3 hr

Nearby

Flash Flood Warnings in Iowa, 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.