Alert archive / South Dakota / Flash Flood Warnings in 1991

Flash Flood Warning 13, NWS Aberdeen, SD

June 20, 1991Codington County, Hamlin County, South Dakota

NWS Aberdeen, SD issued this flash flood warning at Jun 20, 1991, 11:27 PM CDT for Codington County, Hamlin County, South Dakota. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Jun 20, 1991, 11:27 PM CDT (04:27 UTC)
Expired
Jun 21, 1991, 1:30 AM CDT
In force
2 hr
Issued by
NWS Aberdeen, SD
Area
Whole counties

Counties Codington County, SD, Hamlin County, SD

The nearest sounding before it

Aberdeen, SD (KHON), launched 00:00Z, 4.5 hours before the alert went out and 96 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, Aberdeen, SD at 00:00Z on 1991-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3448 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, Aberdeen, SD at 00:00Z on 1991-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
3448 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
1642 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.6
Supercell composite
10.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KHON 210427
FFWHON
SDC029-057-210630-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
FLASH FLOOD WARNING 
NATIONAL WEATHER SERVICE HURON SD 
1127 PM CDT THU JUN 20 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING 
EFFECTIVE UNTIL 130 AM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE EAST CENTRAL PART OF SOUTH DAKOTA
      CODINGTON...HAMLIN

SOME OF THE COMMUNITIES INCLUDED IN THIS WARNING ARE WATERTOWN,
FLORENCE, SOUTH SHORE, AND WAVERLY.

 THIS AREA RECEIVED 2 TO 4 INCHES OF RAIN LAST NIGHT...AND HAS
RECEIVED AN ADDITIONAL 2 TO 4 INCHES AGAIN TONIGHT CAUSING
STREET FLOODING AND FLOODING BASEMENTS...AS WELL AS BLOCKING
INTERSTATE 29 AT WAVERLY. MORE THUNDERSTORMS ARE MOVING INTO
THIS ALREADY SATURATED AREA

A FLASH FLOOD WARNING MEANS FLASH FLOODING IS OCCURING OR IS
IMMINENT. ACT QUICKLY TO SAVE YOURSELF. GET OUT OF LOWLAND AREAS
SUBJECT TO FLOODING. AVOID ALREADY FLOODED AREAS. DO NOT ATTEMPT TO
FORD INUNDATED ROADS. WHEN YOU ARE OUT OF IMMEDIATE DANGER TUNE IN
AREA RADIO AND TELEVISION STATIONS FOR ADDITIONAL INFORMATION.

The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 7:01 PM CDTSevere Thunderstorm WarningABRSpink59 min
Jun 20, 7:08 PM CDTSevere Thunderstorm WarningABRBeadle, Sanborn67 min
Jun 20, 7:17 PM CDTSevere Thunderstorm WarningABRClark58 min
Jun 20, 7:50 PM CDTSevere Thunderstorm WarningABRClark25 min
Jun 20, 8:16 PM CDTSevere Thunderstorm WarningABRCodington, Grant59 min
Jun 20, 8:23 PM CDTSevere Thunderstorm WarningABRClark, Codington, Hamlin67 min
Jun 20, 8:51 PM CDTSevere Thunderstorm WarningABRKingsbury, Miner69 min
Jun 20, 8:54 PM CDTSevere Thunderstorm WarningABRBeadle66 min
Jun 20, 9:13 PM CDTSevere Thunderstorm WarningABRCodington, Deuel, Hamlin62 min
Jun 20, 9:28 PM CDTFlash Flood WarningABRCodington, Hamlin2 hr
Jun 20, 9:57 PM CDTSevere Thunderstorm WarningABRHamlin, Kingsbury63 min
Jun 20, 10:08 PM CDTSevere Thunderstorm WarningABRDay, Marshall37 min
Jun 20, 11:18 PM CDTSevere Thunderstorm WarningABRHamlin57 min
Jun 21, 12:36 AM CDTSevere Thunderstorm WarningABRMiner69 min

Nearby

Flash Flood Warnings in South Dakota, 1991Every flash flood warning in 1991

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.