Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 4, NWS Des Moines, IA

May 11, 2011Adams County, Taylor County, Iowa

NWS Des Moines, IA issued this flash flood warning at May 11, 2011, 2:43 PM CDT for Adams County, Taylor County, Iowa. It was in force for 6 hr. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 11, 2011, 2:43 PM CDT (19:43 UTC)
Expired
May 11, 2011, 8:30 PM CDT
In force
6 hr
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Flood severity
None

Counties Adams County, IA, Taylor County, IA

The radar

The Des Moines radar (KDMX), 130 km from the middle of the area, began a volume at 19:47 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.

What was reported inside it

TimeReportWhereRemark
May 11, 4:30 PM CDTFLASH FLOOD1 Wsw Nodaway, IAADAMS COUNTY LAW ENFORCEMENT REPORTED RAILROAD TRACKS WASHED OUT BETWEEN TRACK MILE MARKERS 423 AND 424.
May 11, 4:30 PM CDTFLASH FLOOD2 Ne Nodaway, IAWATER OVER CHESTNUT AVE BETWEEN 240TH AND 250TH STREET.
May 11, 4:30 PM CDTFLASH FLOODNodaway, IASEVERAL PLACES THROUGHOUT NODAWAY WITH 6 INCHES OF WATER FLOWING OVER ROADS AND INUNDATING HOUSES AND BUSINESSES.
May 11, 5:00 PM CDTFLASH FLOODNodaway, IAWATER UP TO THE RAILROAD TRACKS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.7 hours before the alert went out and 133 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 12:00Z on 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 909 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 12:00Z on 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
909 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
1123 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

797 
WGUS53 KDMX 111943
FFWDMX
IAC003-173-120130-
/O.NEW.KDMX.FF.W.0004.110511T1943Z-110512T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
243 PM CDT WED MAY 11 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN TAYLOR COUNTY IN SOUTHWEST IOWA...
  WESTERN ADAMS COUNTY IN SOUTHWEST IOWA...

* UNTIL 830 PM CDT

* AT 243 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. FLASH FLOODING IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS
  OF NORTHWESTERN TAYLOR AND WESTERN ADAMS COUNTIES...INCLUDING THE
  TOWNS OF CARBON AND NODAWAY.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

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. TURN AROUND...DONT DROWN.

&&

LAT...LON 4079 9493 4116 9494 4116 9475 4079 9479

$$

COGIL
4 follow-up statements
786 
WGUS73 KDMX 112056
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
356 PM CDT WED MAY 11 2011

IAC003-173-120130-
/O.CON.KDMX.FF.W.0004.000000T0000Z-110512T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TAYLOR IA-ADAMS IA-
356 PM CDT WED MAY 11 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR WESTERN ADAMS AND
NORTHWESTERN TAYLOR COUNTIES UNTIL 830 PM CDT...

AT 355 PM CDT...WEATHER SPOTTERS REPORTED THAT THERE IS NO LONGER 
WATER OVER ROADS BUT FIELDS AND DITCHES HAVE STANDING WATER IN THEM. 
ADDITIONAL THUNDERSTORMS ARE HEADED INTO THE WARNED AREA AND MAY 
CAUSE ADDITIONAL FLOODING IF HEAVY RAIN MOVES OVER THE SAME AREAS.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. FLASH  IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF
NORTHWESTERN TAYLOR AND WESTERN ADAMS COUNTIES...INCLUDING THE TOWNS
OF CARBON AND NODAWAY.

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 4079 9493 4116 9494 4116 9475 4079 9479

$$

BOKSA
150 
WGUS73 KDMX 112206
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
506 PM CDT WED MAY 11 2011

IAC003-173-120130-
/O.CON.KDMX.FF.W.0004.000000T0000Z-110512T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TAYLOR IA-ADAMS IA-
506 PM CDT WED MAY 11 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR WESTERN ADAMS AND
NORTHWESTERN TAYLOR COUNTIES UNTIL 830 PM CDT...

AT 500 PM CDT...WEATHER SPOTTERS REPORTED THUNDERSTORMS WITH VERY 
HEAVY RAINFALL ACROSS THE WARNED AREA. RAINFALL RATES OF 2 TO 3 
INCHES PER HOUR CAN BE EXPECTED THROUGH THE NEXT 1 TO 2 HOURS.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. FLASH  IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF
NORTHWESTERN TAYLOR AND WESTERN ADAMS COUNTIES...INCLUDING THE TOWNS
OF CARBON AND NODAWAY.

AT ABOUT 5PM CDT...A STORM SPOTTER REPORTED WATER UP TO RAILROAD 
TRACKS JUST NORTH OF NODAWAY IN WESTERN ADAMS COUNTY.

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 4079 9493 4116 9494 4116 9475 4079 9479

$$

PODRAZIK
879 
WGUS73 KDMX 120001
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
701 PM CDT WED MAY 11 2011

IAC003-173-120130-
/O.CON.KDMX.FF.W.0004.000000T0000Z-110512T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TAYLOR IA-ADAMS IA-
701 PM CDT WED MAY 11 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR WESTERN ADAMS AND
NORTHWESTERN TAYLOR COUNTIES UNTIL 830 PM CDT...

AT 659 PM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. FLASH  IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF
NORTHWESTERN TAYLOR AND WESTERN ADAMS COUNTIES...INCLUDING THE TOWNS
OF CARBON AND NODAWAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS... AS WELL AS FARMLAND ALONG THE 
BANKS OF CREEKS AND STREAMS.

AT 7 PM CDT...ADAMS COUNTY LAW ENFORCEMENT REPORTED FLOODING ISSUES 
CONTINUE WITHIN THE TOWN OF NODAWAY AND THROUGHOUT OTHER PORTIONS OF 
THE ADAMS COUNTY. 

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 4079 9493 4116 9494 4116 9475 4079 9479

$$

PODRAZIK
030 
WGUS73 KDMX 120130
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
830 PM CDT WED MAY 11 2011

IAC003-173-120145-
/O.EXP.KDMX.FF.W.0004.000000T0000Z-110512T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TAYLOR IA-ADAMS IA-
830 PM CDT WED MAY 11 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR WESTERN ADAMS AND
NORTHWESTERN TAYLOR COUNTIES HAS BEEN ALLOWED TO EXPIRE...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 4079 9493 4116 9494 4116 9475 4079 9479

$$

SMALL

The office that day

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

IssuedProductOfficeCountiesLasted
May 11, 12:43 PM CDTSevere Thunderstorm WarningDMXAdams, Cass47 min
May 11, 2:05 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor55 min
May 11, 2:22 PM CDTTornado WarningDMXAdams23 min
May 11, 2:51 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor39 min
May 11, 4:01 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor44 min
May 11, 4:11 PM CDTTornado WarningDMXAdams, Taylor49 min
May 11, 4:42 PM CDTFlash Flood WarningDMXAdams, Taylor6 hr
May 11, 4:50 PM CDTTornado WarningDMXAdams, Union40 min
May 11, 4:57 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor38 min
May 11, 5:32 PM CDTSevere Thunderstorm WarningDMXAdams, Ringgold, Taylor, Union43 min
May 11, 5:42 PM CDTTornado WarningDMXUnion33 min
May 11, 5:44 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Madison, Ringgold, Warren46 min
May 11, 6:03 PM CDTFlash Flood WarningDMXUnion6 hr
May 11, 6:06 PM CDTSevere Thunderstorm WarningDMXAdair, Clarke, Madison, Union54 min
May 11, 6:37 PM CDTSevere Thunderstorm WarningDMXDallas, Madison, Polk, Warren53 min
May 11, 6:42 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Warren48 min
May 11, 6:46 PM CDTSevere Thunderstorm WarningDMXWayne44 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.