Alert archive / Iowa / Flash Flood Warnings in 2002

Flash Flood Warning 8, NWS Sioux Falls, SD

June 20, 2002Woodbury County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Jun 20, 2002, 9:41 PM CDT for Woodbury County, Iowa. It was in force for 49 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: Jun 20, 2002, 9:41 PM CDT (02:41 UTC)
Expired: Jun 20, 2002, 10:30 PM CDT
In force: 49 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Woodbury County, IA

The radar

The Omaha radar (KOAX), 120 km from the middle of the area, began a volume at 02:40 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

Omaha, NE (KOAX), launched 00:00Z, 2.7 hours before the alert went out and 121 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1337 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1609 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KFSD 210241
FFWFSD
IAC193-210330-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
938 PM CDT THU JUN 20 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WOODBURY COUNTY IN NORTHWEST IOWA

* UNTIL 1030 PM CDT

* AT 938 PM CDT...LOCAL LAW ENFORCEMENT REPORTED FLASH FLOODING IN 
THE VICINITY OF CLIMBING HILL.  SEVERAL RURAL ROADS IN THE VICINITY 
OF CLIMBING HAVE BEEN UNDER WATER BECAUSE OF THE TWO TO TWO AND 
ONE-HALF INCHES OF RAIN IN LESS THAN AN HOUR.  ALTHOUGH THE STORM IS 
WEAKENING...HEAVY RAIN WILL CONTINUE TO FALL IN THE ANTHON AREA 
WHICH WILL PRODUCE ADDITIONAL FLOODING ACROSS ROADS IN LOW LYING 
AREAS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES...AS WELL AS
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

LAT...LON 4243 9619 4225 9615 4227 9579 4249 9582

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 8:27 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	33 min
Jun 20, 8:56 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	34 min
Jun 20, 9:05 PM CDT	Tornado Warning	FSD	Woodbury	25 min

Nearby

Flash Flood Warnings in Iowa, 2002 Every 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.