Alert archive / Iowa / Flash Flood Warnings in 2001

Flash Flood Warning 17, NWS Des Moines, IA

August 24, 2001Calhoun County, Carroll County, Sac County, Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 24, 2001, 6:16 PM CDT for Calhoun County, Carroll County, Sac County, Iowa. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Aug 24, 2001, 6:16 PM CDT (23:16 UTC)
Expired: Aug 24, 2001, 9:15 PM CDT
In force: 3 hr
Issued by: NWS Des Moines, IA
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Calhoun County, IA, Carroll County, IA, Sac County, IA

The radar

The Des Moines radar (KDMX), 114 km from the middle of the area, began a volume at 23:17 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 12:00Z, 11.3 hours before the alert went out and 157 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: 370 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 486 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 32 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 KDMX 242316
FFWDSM
FFWDSM
IAC025-027-161-250215-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
616 PM CDT FRI AUG 24 2001

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN CALHOUN COUNTY IN WEST CENTRAL IOWA
  NORTHERN CARROLL COUNTY IN WEST CENTRAL IOWA
  SOUTHEASTERN SAC COUNTY IN WEST CENTRAL IOWA

* UNTIL 915 PM CDT

* AT 612 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH FLASH FLOOD PRODUCING RAINS 17 MILES SOUTHEAST
  OF LAKE VIEW...OR ABOUT 43 MILES SOUTHWEST OF FORT DODGE...MOVING
  NORTHEAST AT 20 MPH.

* THUNDERSTORMS ARE CONTINUOUSLY REDEVELOPING OVER THE WARNING
  AREA...RESULTING IN EXCESSIVE RAINFALL. RAINFALL RATES WILL AVERAGE
  2 TO 3 INCHES PER HOUR. THIS WILL PRODUCE FLASH FLOODING MAINLY IN 
  RURAL LOCATIONS AND NEAR HIGHWAY 71 NORTH OF CARROLL.

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA...LIVING NEAR THE AFFECTED
WATERWAYS...YOU SHOULD TAKE IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND
PROPERTY.

LAT...LON 4236 9522 4207 9510 4206 9464 4219 9464
          4226 9479 4235 9488

KNOLLHOFF

Nearby

Flash Flood Warnings in Iowa, 2001 Every flash flood warning in 2001

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.