Alert archive / South Dakota / Flash Flood Warnings in 2002

Flash Flood Warning 13, NWS Sioux Falls, SD

August 20, 2002Aurora County, Davison County, South Dakota

NWS Sioux Falls, SD issued this flash flood warning at Aug 20, 2002, 9:42 PM CDT for Aurora County, Davison County, South Dakota. It was in force for 108 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 20, 2002, 9:42 PM CDT (02:42 UTC)
Expired
Aug 20, 2002, 11:30 PM CDT
In force
108 min
Issued by
NWS Sioux Falls, SD
Area
Counties, with a storm outline in the text

Counties Aurora County, SD, Davison County, SD

The radar

The Sioux Falls radar (KFSD), 123 km from the middle of the area, began a volume at 02:44 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.7 hours before the alert went out and 133 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 2002-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 2002-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 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
1 J/kg
Mixed-layer CIN
-265 J/kg
Mixed-layer LCL
857 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KFSD 210242
FFWFSD
SDC003-035-210430-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
941 PM CDT TUE AUG 20 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN AURORA COUNTY IN SOUTHEAST SOUTH DAKOTA
  DAVISON COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 1130 PM CDT

* AT 941 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS WERE PRODUCING VERY HEAVY RAINFALL OVER EASTERN  
  AURORA COUNTY MOVING INTO DAVISON COUNTY. PREVIOUS STORMS HAVE
  PRODUCED UP TO 4 INCHES OF RAIN...AND ADDTIONAL HEAVY RAINS ARE
  EXPECTED. 

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS AND STREAMS AND OTHER
LOW LYING AREAS ARE SUBJECT TO FLASH FLOODING.

LAT...LON 4383 9802 4352 9800 4352 9858 4384 9862

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 7:17 PM CDTSevere Thunderstorm WarningFSDDavison, Sanborn43 min
Aug 20, 7:25 PM CDTSevere Thunderstorm WarningFSDAurora35 min
Aug 20, 7:48 PM CDTSevere Thunderstorm WarningFSDGregory42 min
Aug 20, 8:25 PM CDTSevere Thunderstorm WarningFSDHanson50 min
Aug 20, 8:31 PM CDTSevere Thunderstorm WarningFSDDavison29 min
Aug 20, 8:47 PM CDTSevere Thunderstorm WarningFSDLake, Miner43 min
Aug 20, 9:02 PM CDTSevere Thunderstorm WarningFSDMcCook43 min
Aug 20, 9:10 PM CDTTornado WarningFSDHanson35 min
Aug 20, 9:10 PM CDTTornado WarningFSDHanson35 min
Aug 20, 9:17 PM CDTSevere Thunderstorm WarningFSDAurora43 min
Aug 20, 9:25 PM CDTSevere Thunderstorm WarningFSDDouglas50 min
Aug 20, 9:42 PM CDTSevere Thunderstorm WarningFSDMinnehaha63 min
Aug 20, 9:44 PM CDTSevere Thunderstorm WarningFSDMcCook46 min
Aug 20, 10:11 PM CDTSevere Thunderstorm WarningFSDHutchinson49 min
Aug 21, 7:46 AM CDTFlash Flood WarningFSDMinnehaha119 min
Aug 21, 6:54 PM CDTSevere Thunderstorm WarningFSDGregory51 min

Nearby

Flash Flood Warnings in South Dakota, 2002Every flash flood warning in 2002

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; radar from the NEXRAD Level II archive.