Alert archive / Iowa / Flash Flood Warnings in 2002

Flash Flood Warning 12, NWS Des Moines, IA

August 23, 20024 counties in Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 23, 2002, 12:15 AM CDT for 4 counties in Iowa. It was in force for 6 hr. 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 23, 2002, 12:15 AM CDT (05:15 UTC)
Expired
Aug 23, 2002, 6:15 AM CDT
In force
6 hr
Issued by
NWS Des Moines, IA
Area
Counties, with a storm outline in the text

Counties Audubon County, IA, Dallas County, IA, Guthrie County, IA, Polk County, IA

The radar

The Des Moines radar (KDMX), 29 km from the middle of the area, began a volume at 05:19 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, 5.3 hours before the alert went out and 197 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 2002-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3464 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, Omaha, NE at 00:00Z on 2002-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
3464 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
856 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
2.0
Supercell composite
11.3

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KDMX 230519
FFWDSM
IAC009-049-077-153-231115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1215 AM CDT FRI AUG 23 2002

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DALLAS COUNTY IN CENTRAL IOWA
  POLK COUNTY IN CENTRAL IOWA
  THIS INCLUDES THE CITY OF DES MOINES
  SOUTHERN AUDUBON COUNTY IN WEST CENTRAL IOWA
  GUTHRIE COUNTY IN WEST CENTRAL IOWA

* UNTIL 615 AM

* AT 1215 AM...WEATHER SERVICE DOPPLER RADAR INDICATED NUMEROUS 
THUNDERSTORMS PRODUCING VERY HEAVY RAIN...IN THESE COUNTIES. THE 
MOST LIKELY AREAS TO SEE SIGNIFICANT FLOODING WOULD BE IN THE CITIES 
AS WELL AS SMALL STREAMS AND RIVERS. THE HEAVY RAINS WILL CONTINUE 
FOR THE NEXT 2 TO 3 HOURS AND CONDITIONS SHOULD IMPROVE AS THE RAIN 
TAPERS OFF.

*

OTHER WARNING LOCATIONS INCLUDE...
ADEL...ALLEMAN...ALTOONA...ANKENY...AUDUBON...BAGLEY...BONDURANT...
BOUTON...BRAYTON...CLIVE...DALLAS CENTER...DAWSON...DE SOTO...
ELKHART...EXIRA...GRANGER...GRAY...GRIMES...GUTHRIE CENTER...
JAMAICA...JOHNSTON...KIMBALLTON...LINDEN...MINBURN...MITCHELLVILLE...
PANORA...PERRY...PLEASANT HILL...POLK CITY...REDFIELD...
SAYLORVILLE...URBANDALE...VAN METER...WAUKEE...WEST DES MOINES...
WINDSOR HEIGHTS AND YALE

FLASH FLOODS OCCUR QUICKLY...MOVE TO HIGHER GROUND. AVOID WATER
COVERED ROADS...THE ROAD MAY BE WASHED OUT. LESS THAN ONE FOOT OF
FAST FLOWING WATER CAN SWEEP AN AUTOMOBILE OFF THE ROAD.

LAT...LON 4184 9335 4151 9336 4152 9513 4185 9514

BARLOW

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 23, 12:15 AM CDTFlash Flood WarningDMXAudubon, Dallas, Guthrie, Polk18 hr
Aug 23, 12:28 AM CDTSevere Thunderstorm WarningDMXPolk47 min
Aug 23, 12:54 AM CDTSevere Thunderstorm WarningDMXJasper51 min

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.