Alert archive / Iowa / Flash Flood Warnings in 2004

Flash Flood Warning 53, NWS Des Moines, IA

September 17, 2004Palo Alto County, Pocahontas County, Iowa

NWS Des Moines, IA issued this flash flood warning at Sep 17, 2004, 3:49 PM CDT for Palo Alto County, Pocahontas County, 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: Sep 17, 2004, 3:49 PM CDT (20:49 UTC)
Expired: Sep 17, 2004, 9:45 PM CDT
In force: 6 hr
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Palo Alto County, IA, Pocahontas County, IA

The radar

The Des Moines radar (KDMX), 161 km from the middle of the area, began a volume at 20:49 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

Minneapolis, MN (KMPX), launched 12:00Z, 8.8 hours before the alert went out and 228 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1449 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 414 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 KDMX 172051
FFWDMX
IAC147-151-180245-
/X.NEW.KDMX.FF.W.0005.040917T2049Z-040918T0245Z/
/0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
349 PM CDT FRI SEP 17 2004

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  PALO ALTO COUNTY IN NORTHWEST IOWA.
  POCAHONTAS COUNTY IN NORTHWEST IOWA.

* UNTIL 945 PM CDT.

* AT 345 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.     
  REPORTS FROM SPOTTERS HAVE INDICATED AROUND 2 INCHES OF RAINFALL
  SO FAR IN SOUTHERN PALO ALTO INTO NORTHERN POCAHONTAS COUNTIES. 

* SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN THE
  WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH
  FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING    
  INCLUDE...LAURENS...AYRSHIRE...CURLEW...CYLINDER...HAVELOCK...     
  MALLARD AND PLOVER.

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.

LAT...LON 4324 9491 4258 9490 4257 9447 4324 9449

$$

COGIL

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 17, 3:02 PM CDT	Severe Thunderstorm Warning	DMX	Pocahontas	43 min
Sep 17, 3:17 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto	43 min
Sep 17, 3:44 PM CDT	Severe Thunderstorm Warning	DMX	Pocahontas	46 min
Sep 17, 4:28 PM CDT	Severe Thunderstorm Warning	DMX	Pocahontas	57 min
Sep 17, 5:08 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Webster	52 min

Nearby

Flash Flood Warnings in Iowa, 2004 Every flash flood warning in 2004

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.