Alert archive / Iowa / Flash Flood Warnings in 1986

Flash Flood Warning 2, NWS Des Moines, IA

June 29, 1986Dallas County, Polk County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 29, 1986, 10:25 PM CDT for Dallas County, Polk County, Iowa. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Jun 29, 1986, 10:25 PM CDT (03:25 UTC)
Expired
Jun 30, 1986, 4:00 AM CDT
In force
6 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Dallas County, IA, Polk 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 00:00Z, 3.4 hours before the alert went out and 217 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 00:00Z on 1986-06-30Temperature 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 00:00Z on 1986-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 119 square meters per square second.19395878Sfc1 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
3623 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
119 m²/s²
0-3 km storm-relative helicity
262 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 300326
FFWDSM
IAC153-049-300900-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1025 PM CDT SUN JUN 29 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL 400 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

CENTRAL IOWA...EXTREME WESTERN POLK AND EXTREME EASTERN DALLAS

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

AT 1020 PM CDT REPORTS INDICATED THAT HEAVY RAINS WERE ALREADY
AFFECTING WALNUT CREEK AND WAS RUNNING OUT OF ITS BANKS.

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.

DO NOT ATTEMPT TO CROSS A FLOWING STREAM ON FOOT WHERE THE WATER
IS ABOVE YOUR KNEES.

FORSTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 7:30 PM CDTSevere Thunderstorm WarningDMXCalhoun45 min
Jun 29, 8:26 PM CDTSevere Thunderstorm WarningDMXGreene49 min
Jun 29, 9:00 PM CDTSevere Thunderstorm WarningDMXEmmet45 min
Jun 29, 10:00 PM CDTSevere Thunderstorm WarningDMXGuthrie40 min
Jun 29, 10:18 PM CDTSevere Thunderstorm WarningDMXCass42 min
Jun 29, 11:50 PM CDTTornado WarningDMXPolk25 min
Jun 30, 1:12 AM CDTSevere Thunderstorm WarningDMXIowa, Poweshiek48 min
Jun 30, 3:45 AM CDTFlash Flood WarningDMXPolk6 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.