Alert archive / Iowa / Flash Flood Warnings in 2002

Flash Flood Warning 22, NWS Sioux Falls, SD

May 29, 2002Woodbury County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at May 29, 2002, 12:55 AM CDT for Woodbury County, Iowa. It was in force for 95 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
May 29, 2002, 12:55 AM CDT (05:55 UTC)
Expired
May 29, 2002, 2:30 AM CDT
In force
95 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), 123 km from the middle of the area, began a volume at 05:58 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, 5.9 hours before the alert went out and 123 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 2002-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2280 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, Omaha, NE at 00:00Z on 2002-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.1939Sfc1 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
2280 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1163 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
118 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 
WGUS53 KFSD 290555 CCA
FFWFSD
IAC193-290730-

BULLETIN - EAS ACTIVATION REQUESTED...CORRECTED FOR EXPIRATION...
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1255 AM CDT WED MAY 29 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

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

* UNTIL 230 AM CDT

* AT 1255 AM CDT...LAW ENFORCEMENT REPORTED STREET FLOODING IN 
DOWNTOWN SIOUX CITY.  NATIONAL WEATHER SERVICE DOPPLER RADAR 
INDICATED VERY HEAVY RAINFALL WITH THUNDERSTORMS CONTINUING TO MOVE 
ACROSS THE SIOUX CITY AREA.  THIS STORMS WILL CONTINUE THROUGH 130 
AM AND WILL RESULT IN ANOTHER INCH OF RAIN ACROSS PORTIONS OF THE 
CITY. THIS WILL RESULT IN MORE RUNOFF AND WATER ACCUMULATING IN 
STREETS AND LOW LYING AREAS. 

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.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

LAT...LON 4256 9637 4230 9635 4232 9619 4240 9619

The office that day

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

IssuedProductOfficeCountiesLasted
May 29, 12:55 AM CDTFlash Flood WarningFSDWoodbury20 min
May 29, 1:12 AM CDTFlash Flood WarningFSDPlymouth93 min
May 29, 2:25 AM CDTFlash Flood WarningFSDWoodbury3 hr
May 29, 2:41 AM CDTFlash Flood WarningFSDPlymouth3 hr

Nearby

Flash Flood Warnings in Iowa, 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.