Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 34, NWS Des Moines, IA

August 4, 2011Clarke County, Lucas County, Warren County, Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 4, 2011, 5:55 PM CDT for Clarke County, Lucas County, Warren 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 as issued.

The facts

Issued
Aug 4, 2011, 5:55 PM CDT (22:55 UTC)
Expired
Aug 4, 2011, 9:07 PM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Flood severity
None

Counties Clarke County, IA, Lucas County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 70 km from the middle of the area, began a volume at 22:55 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, 10.9 hours before the alert went out and 241 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 2011-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 116 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 2011-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 square meters per square second.193958Sfc1 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
116 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
949 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
59 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.

422 
WGUS53 KDMX 042255
FFWDMX
IAC039-117-181-050500-
/O.NEW.KDMX.FF.W.0034.110804T2255Z-110805T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
555 PM CDT THU AUG 4 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN CLARKE COUNTY IN SOUTH CENTRAL IOWA...
  NORTHWESTERN LUCAS COUNTY IN SOUTH CENTRAL IOWA...
  SOUTH CENTRAL WARREN COUNTY IN SOUTH CENTRAL IOWA...

* UNTIL MIDNIGHT CDT FRIDAY

* AT 554 PM CDT...STORMS OVER WESTERN LUCAS COUNTY HAVE PRODUCED A   
  RADAR INDICATED 3 TO 5 INCHES OF RAIN OVER THE WARNED AREA.        
  RAINFALL IS EXPECTED TO CONTINUE.  

* FLASH FLOODING IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF
  NORTHEASTERN CLARKE...NORTHWESTERN LUCAS AND SOUTH CENTRAL WARREN
  COUNTIES...INCLUDING THE TOWNS OF CHARITON AIRPORT...LACONA...LUCAS
  AND OSCEOLA AIRPORT.

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.

&&

LAT...LON 4121 9336 4097 9336 4104 9370 4121 9370

$$

AW
3 follow-up statements
242 
WGUS73 KDMX 042359
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
659 PM CDT THU AUG 4 2011

IAC039-117-181-050500-
/O.CON.KDMX.FF.W.0034.000000T0000Z-110805T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WARREN IA-LUCAS IA-CLARKE IA-
659 PM CDT THU AUG 4 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHEASTERN CLARKE...
NORTHWESTERN LUCAS AND SOUTH CENTRAL WARREN COUNTIES UNTIL MIDNIGHT
CDT...

AT 658 PM CDT...HEAVY RAINFALL ACROSS THE WARNED AREA HAS COME TO AN 
END...WITH LIGHTER PRECIPITATION PERSISTING. RADAR ESTIMATES OF 3 TO 
5 INCHES OF RAINFALL ACROSS THE AREA COULD LEAD TO AREAS OF FLASH 
FLOODING.

FLASH  IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF NORTHEASTERN
CLARKE...NORTHWESTERN LUCAS AND SOUTH CENTRAL WARREN COUNTIES...
INCLUDING THE TOWNS OF CHARITON AIRPORT...LACONA...LUCAS AND OSCEOLA
AIRPORT.

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.

&&

LAT...LON 4121 9336 4097 9336 4104 9370 4121 9370

$$

AW
305 
WGUS73 KDMX 050057
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
757 PM CDT THU AUG 4 2011

IAC039-117-181-050500-
/O.CON.KDMX.FF.W.0034.000000T0000Z-110805T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WARREN IA-LUCAS IA-CLARKE IA-
757 PM CDT THU AUG 4 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHEASTERN CLARKE...
NORTHWESTERN LUCAS AND SOUTH CENTRAL WARREN COUNTIES UNTIL MIDNIGHT
CDT...

AT 756 PM CDT...HEAVY RAINFALL ACROSS THE WARNED AREA HAS COME TO AN 
END...WITH LIGHTER PRECIPITATION PERSISTING ACROSS EASTERN CLARKE 
AND LUCAS COUNTIES. RADAR ESTIMATES OF 3 TO 5 INCHES OF RAINFALL 
ACROSS THE AREA COULD LEAD TO AREAS OF FLASH FLOODING.

FLASH  IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF NORTHEASTERN
CLARKE...NORTHWESTERN LUCAS AND SOUTH CENTRAL WARREN COUNTIES...
INCLUDING THE TOWNS OF CHARITON AIRPORT...LACONA...LUCAS AND OSCEOLA
AIRPORT.

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.

&&

LAT...LON 4121 9336 4097 9336 4104 9370 4121 9370

$$

AW
557 
WGUS73 KDMX 050207
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
907 PM CDT THU AUG 4 2011

IAC039-117-181-050223-
/O.CAN.KDMX.FF.W.0034.000000T0000Z-110805T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WARREN IA-LUCAS IA-CLARKE IA-
907 PM CDT THU AUG 4 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHEASTERN
CLARKE...NORTHWESTERN LUCAS AND SOUTH CENTRAL WARREN COUNTIES IS
CANCELLED...

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 4121 9336 4097 9336 4104 9370 4121 9370

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 3:14 PM CDTSevere Thunderstorm WarningDMXWarren31 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.