Alert archive / Minnesota / Flash Flood Warnings in 2002

Flash Flood Warning 14, NWS Sioux Falls, SD

August 21, 2002Rock County, Minnesota; Minnehaha County, South Dakota

NWS Sioux Falls, SD issued this flash flood warning at Aug 21, 2002, 7:46 AM CDT for Rock County, Minnesota; Minnehaha County, South Dakota. It was in force for 119 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 21, 2002, 7:46 AM CDT (12:46 UTC)
Expired
Aug 21, 2002, 9:45 AM CDT
In force
119 min
Issued by
NWS Sioux Falls, SD
Area
Counties, with a storm outline in the text

Counties Rock County, MN, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 27 km from the middle of the area, began a volume at 12:46 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 12:00Z, 0.8 hours before the alert went out and 212 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 12:00Z on 2002-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 35 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 2002-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 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
35 J/kg
Mixed-layer CIN
-251 J/kg
Mixed-layer LCL
679 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KFSD 211246
FFWFSD
MNC133-SDC099-211445-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
743 AM CDT WED AUG 21 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ROCK COUNTY IN SOUTHWEST MINNESOTA
  SOUTHERN MINNEHAHA COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 945 AM CDT

* AT 743 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAINFALL WAS OCCURRING OVER THE WARNED AREA.

RAINFALL TOTALS OF 3 TO 5 INCHES HAVE BEEN REPORTED OVERNIGHT IN THE 
WARNED AREA...AND THE THUNDERSTORMS CURRENTLY MOVING THROUGH THE 
AREA WILL PRODUCE AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL IN THE 
NEXT HOUR. FLOODING OF STREETS...INTERSECTIONS...AND UNDERPASSES IN 
URBAN AREAS WILL BE THE PRIMARY THREAT...BUT RAPID RISES ON 
DITCHES...CREEKS...AND STREAMS IN RURAL AREAS WILL ALSO OCCUR. 

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

LAT...LON 4371 9611 4353 9611 4352 9682 4374 9683

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 CDTFlash Flood WarningFSDAurora, Davison108 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, 6:54 PM CDTSevere Thunderstorm WarningFSDGregory51 min

Nearby

Flash Flood Warnings in Minnesota, 2002Flash 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.