Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 3, NWS Des Moines, IA

February 20, 2011Webster County, Iowa

NWS Des Moines, IA issued this flash flood warning at Feb 20, 2011, 6:09 PM CST for Webster 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: Feb 20, 2011, 6:09 PM CST (00:09 UTC)
Expired: Feb 21, 2011, 12:00 AM CST
In force: 6 hr
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Flood severity: None

County Webster County, IA

The radar

The Des Moines radar (KDMX), 92 km from the middle of the area, began a volume at 00:10 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 00:00Z, 0.2 hours before the alert went out and 266 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: 700 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 523 m²/s²
0-3 km storm-relative helicity: 620 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.

833 
WGUS53 KDMX 210009
FFWDMX
IAC187-210600-
/O.NEW.KDMX.FF.W.0003.110221T0009Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
609 PM CST SUN FEB 20 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR ICE JAM FLOODING IN...
  CENTRAL WEBSTER COUNTY IN CENTRAL IOWA...

* UNTIL MIDNIGHT CST

* AT 605 PM CST...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING   
ACROSS THE WARNED AREA. A TRAINED SPOTTER REPORTS THAT WATER IS 
RISING QUICKLY IN THE BREEN HOUSING ADDITION...LOCATED NORTH OR NEAR 
RIVERDALE DRIVE IN THE PAST 20 MINUTES. ROAD ACCESS CONTINUES TO BE 
A PROBLEM AND ROADS ARE ONCE AGAIN BLOCKED DUE TO WATER AND ICE 
FLOWS. IT IS LIKELY THAT THE WATER WILL CONTINUE TO RISE IF THE ICE 
JAM CONTINUES TO HOLD FOR SEVERAL MORE HOURS. 

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...FORT DODGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY AUTOMOBILE.

&&

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

VACHALEK

6 follow-up statements

182 
WGUS73 KDMX 210105
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
705 PM CST SUN FEB 20 2011

IAC187-210600-
/O.CON.KDMX.FF.W.0003.000000T0000Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
705 PM CST SUN FEB 20 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT FOR
CENTRAL WEBSTER COUNTY UNTIL MIDNIGHT CST...

AT 658 PM CST...WEATHER SPOTTERS REPORTED THAT FLASH FLOODING WAS 
OCCURRING ON THE DES MOINES RIVER NEAR THE FORT DODGE AIRPORT.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH  FLOODING INCLUDE...FORT
DODGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AT 600 PM CST...A TRAINED WEATHER SPOTTER REPORTED THAT WATER WAS 
RISING RAPIDLY ON THE DES MOINES RIVER NEAR THE FORT DODGE AIRPORT 
DUE TO ICE JAMMING. HOMES WERE BEING THREATENED ON RIVERDALE 
DRIVE...AND IN THE BREEN ADDITION JUST NORTHWEST OF THE AIRPORT.

AT 620 PM CST...WATER WAS REPORTED OVER THE ROADS IN SOME OF THESE 
AREAS...AND ALSO ON PARTS OF MADISON AVENUE NEAR COUNTY HIGHWAY D 14.

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

LEE

854 
WGUS73 KDMX 210157
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
757 PM CST SUN FEB 20 2011

IAC187-210600-
/O.CON.KDMX.FF.W.0003.000000T0000Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
757 PM CST SUN FEB 20 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT FOR
CENTRAL WEBSTER COUNTY UNTIL MIDNIGHT CST...

AT 756 PM CST...WEATHER SPOTTERS REPORTED THAT FLASH FLOODING WAS 
OCCURRING ON THE DES MOINES RIVER NEAR THE FORT DODGE 
AIRPORT...MAINLY BETWEEN RIVERDALE DRIVE AND THE BREEN ADDITION.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH  FLOODING INCLUDE...FORT
DODGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

LEE

120 
WGUS73 KDMX 210304
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
904 PM CST SUN FEB 20 2011

IAC187-210600-
/O.CON.KDMX.FF.W.0003.000000T0000Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
904 PM CST SUN FEB 20 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT FOR
CENTRAL WEBSTER COUNTY UNTIL MIDNIGHT CST...

AT 904 PM CST...WEATHER SPOTTERS REPORTED THAT FLASH FLOODING WAS 
OCCURRING ON THE DES MOINES RIVER NEAR THE FORT DODGE 
AIRPORT...MAINLY BETWEEN RIVERDALE DRIVE AND THE BREEN ADDITION.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH  FLOODING INCLUDE...FORT
DODGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

LEE

396 
WGUS73 KDMX 210359
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
959 PM CST SUN FEB 20 2011

IAC187-210600-
/O.CON.KDMX.FF.W.0003.000000T0000Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
959 PM CST SUN FEB 20 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT FOR
CENTRAL WEBSTER COUNTY UNTIL MIDNIGHT CST...

AT 957 PM CST...WEATHER SPOTTERS REPORTED THAT FLASH FLOODING WAS 
OCCURRING ON THE DES MOINES RIVER NEAR THE FORT DODGE 
AIRPORT...MAINLY BETWEEN RIVERDALE DRIVE AND THE BREEN ADDITION.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...FORT 
DODGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

LEE

684 
WGUS73 KDMX 210459
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1059 PM CST SUN FEB 20 2011

IAC187-210600-
/O.CON.KDMX.FF.W.0003.000000T0000Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
1059 PM CST SUN FEB 20 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT FOR
CENTRAL WEBSTER COUNTY UNTIL MIDNIGHT CST...

AT 1055 PM CST...NO CHANGES TO THE EXTENT OF FLOODING HAS BEEN NOTED 
FOR THE PAST HOUR.  WEATHER SPOTTERS REPORTED THAT FLASH FLOODING 
WAS OCCURRING ON THE DES MOINES RIVER NEAR THE FORT DODGE AIRPORT... 
MAINLY BETWEEN RIVERDALE DRIVE AND THE BREEN ADDITION. WATER IS 
REPORTED OVER THE ROADS IN SOME OF THESE AREAS...AND ALSO NORTH AND 
SOUTH OF COUNTY HIGHWAY D14 ALONG MADISON AVENUE. SEVERAL HOMES IN 
TWO NEIGHBORHOODS REMAIN IMPACTED FROM THE BACK UP OF RIVER FLOW 
THIS EVENING. 

SOME LOCATIONS THAT MAY EXPERIENCE FLASH FLOODING INCLUDE...FORT 
DODGE. IF THE ICE JAM BREAKS SUDDENLY OVERNIGHT...A QUICK RISE IN 
RIVER LEVEL MAY BE SEEN DOWNSTREAM INTO FORT DODGE AND THEN SOUTH OF 
THE CITY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

VACHALEK

830 
WGUS73 KDMX 210602
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1202 AM CST MON FEB 21 2011

IAC187-210613-
/O.EXP.KDMX.FF.W.0003.000000T0000Z-110221T0600Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
1202 AM CST MON FEB 21 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL WEBSTER
COUNTY WILL BE ALLOWED TO EXPIRE AT MIDNIGHT CST...

NO ADDITIONAL RAPID RISES HAVE OCCURRED IN THE WARNED AREA...THOUGH 
SOME FLOODING IS STILL OCCURRING.  IF ANY FLASH FLOODING 
ADDITIONALLY IS OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW 
ENFORCEMENT AGENCY.

LAT...LON 4257 9419 4248 9415 4242 9404 4241 9412
      4246 9420 4256 9424

$$

VACHALEK

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 20, 8:39 PM CST	River Flood Warning	DMX	Boone, Hamilton, Webster	71 hr
Feb 21, 9:46 AM CST	River Flood Warning	DMX	Webster	11 days

Nearby

Flash Flood Warnings in Iowa, 2011 Every flash flood warning in 2011

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.