Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 2, NWS Des Moines, IA

February 19, 2011Webster County, Iowa

NWS Des Moines, IA issued this flash flood warning at Feb 19, 2011, 3:43 AM 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 19, 2011, 3:43 AM CST (09:43 UTC)
Expired
Feb 19, 2011, 9:30 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 09:45 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, 9.7 hours before the alert went out and 225 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 2011-02-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-02-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2198 m above ground
0-6 km bulk shear
78 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
248 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.

822 
WGUS53 KDMX 190943
FFWDMX
IAC187-191530-
/O.NEW.KDMX.FF.W.0002.110219T0943Z-110219T1530Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
343 AM CST SAT FEB 19 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR ICE JAM FLOODING ALONG THE DES MOINES      
  RIVER IN...
  CENTRAL WEBSTER COUNTY IN CENTRAL IOWA...

* UNTIL 930 AM CST

* AT 339 AM CST...AN ICE JAM WAS REPORTED ALONG THE DES MOINES RIVER 
IN FORT DODGE AND WAS CAUSING RAPID RISES UPSTREAM OF THE JAM. THIS 
JAM COULD CAUSE THE DES MOINES RIVER TO RISE NEARLY 2 FEET ABOVE 
FLOOD STAGE OVER A SHORT PERIOD OF TIME.

* 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 THE DES MOINES RIVER THAT TYPICALLY HAVE 
FLOODING PROBLEMS DUE TO ICE JAMS SHOULD TAKE ACTION NOW.  
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

$$

DONAVON
4 follow-up statements
630 
WGUS73 KDMX 191151
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
551 AM CST SAT FEB 19 2011

IAC187-191530-
/O.CON.KDMX.FF.W.0002.000000T0000Z-110219T1530Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
551 AM CST SAT FEB 19 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT ALONG 
THE DES MOINES RIVER IN CENTRAL WEBSTER COUNTY UNTIL 930 AM CST...

AT 546 AM CST...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED THAT THE 
DES MOINES RIVER WAS BEGINNING TO FLOW IN FORT DODGE THOUGH IS 
POSSIBLY STILL ICED OVER SOUTH OF TOWN. ADDITIONAL JAMS REMAIN 
POSSIBLE AS THIS ICE FLOW MOVES SOUTH. AT 5 AM...THE RIVER STAGE IN 
FORT DODGE WAS 12.1 FT WHICH IS AN INCREASE OVER THE 2 AM STAGE OF 
8.4 FT. FLOOD STAGE IS 10.5 FT. THE WATER IS EXPECTED TO DROP BELOW 
FLOOD STAGE ONCE THE ICE JAM RELEASES DOWN STREAM.

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

$$

DONAVON
574 
WGUS73 KDMX 191327
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
727 AM CST SAT FEB 19 2011

IAC187-191530-
/O.CON.KDMX.FF.W.0002.000000T0000Z-110219T1530Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
727 AM CST SAT FEB 19 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING ALONG THE DES MOINES 
RIVER REMAINS IN EFFECT FOR CENTRAL WEBSTER COUNTY UNTIL 930 AM 
CST...

AT 724 AM CST...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED THAT THE 
DES MOINES RIVER WAS BEGINNING TO FLOW IN FORT DODGE THOUGH IS 
POSSIBLY STILL ICED OVER SOUTH OF TOWN. ADDITIONAL JAMS REMAIN 
POSSIBLE AS THIS ICE FLOW MOVES SOUTH. AT 7 AM...THE RIVER STAGE IN 
FORT DODGE REMAINED ABOVE FLOOD STAGE NEAR 12.1 FT. FLOOD STAGE IS 
10.5 FT. THE WATER IS EXPECTED TO DROP BELOW FLOOD STAGE ONCE THE 
ICE JAM RELEASES DOWN STREAM LATER TODAY.

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

$$

DONAVON
577 
WGUS73 KDMX 191502
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
902 AM CST SAT FEB 19 2011

IAC187-191530-
/O.CON.KDMX.FF.W.0002.000000T0000Z-110219T1530Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
902 AM CST SAT FEB 19 2011

...FLASH FLOOD WARNING FOR ICE JAM FLOODING REMAINS IN EFFECT FOR
CENTRAL WEBSTER COUNTY UNTIL 930 AM CST...

AT 854 AM CST...AN ICE JAM ON THE DES MOINES RIVER NEAR FORT DODGE 
CONTINUED TO PRODUCE MINOR FLOODING IN AND NEAR THE CITY.  THE RIVER 
LEVEL ROSE NEARLY 3.7 FEET IN AROUND TWO HOURS EARLY SATURDAY 
MORNING.

THE 800 AM STAGE WAS 12.02 FEET...AND HAS BEEN FAIRLY STEADY 
RECENTLY.  IT IS EXPECTED TO BEGIN FALLING LATER THIS MORNING 
HOWEVER...DROPPING BELOW FLOOD STAGE LATER TODAY.  A RIVER FLOOD 
WARNING WILL LIKELY BE ISSUED FOR THIS LOCATION ONCE THIS FLASH 
FLOOD WARNING EXPIRES.

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

$$

SMALL
416 
WGUS73 KDMX 191530
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
930 AM CST SAT FEB 19 2011

IAC187-191541-
/O.EXP.KDMX.FF.W.0002.000000T0000Z-110219T1530Z/
/00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WEBSTER IA-
930 AM CST SAT FEB 19 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL WEBSTER
COUNTY WILL BE ALLOWED TO EXPIRE AT 930 AM CST...

THE DES MOINES RIVER AT FORT DODGE APPEARS TO BE RECEDING AFTER AN 
ICE JAM CAUSED RAPID RISES EARLIER THIS MORNING.  NO ADDITIONAL 
RAPID RISES ARE ANTICIPATED SO THE FLASH FLOOD WARNING HAS BEEN 
ALLOWED TO EXPIRE. 

A RIVER FLOOD WARNING REMAINS IN EFFECT HOWEVER.  THE 900 AM STAGE 
WAS 11.9 FEET AND SLOWLY FALLING.  FLOOD STAGE IS 10.5 FEET.  PLEASE 
MONITOR LATER RIVER FLOOD STATEMENTS FOR UPDATED INFORMATION.

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

$$

SMALL

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 18, 7:54 PM CSTRiver Flood WarningDMXHumboldt, Kossuth8 days
Feb 19, 4:02 AM CSTWinter Storm WarningDMXBremer, Cerro Gordo, Emmet, Hancock, Kossuth, Palo Alto and 2 more33 hr
Feb 19, 9:25 AM CSTRiver Flood WarningDMXWebster32 hr
Feb 19, 4:20 PM CSTWinter Weather AdvisoryDMXBlack Hawk, Bremer, Butler, Franklin, Grundy, Humboldt and 2 more17 hr

Nearby

Flash Flood Warnings in Iowa, 2011Every 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.