Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 18, NWS Sioux Falls, SD

June 26, 2011Plymouth County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Jun 26, 2011, 8:17 PM CDT for Plymouth County, Iowa. It was in force for 3 hr. 3 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
Jun 26, 2011, 8:17 PM CDT (01:17 UTC)
Expired
Jun 26, 2011, 11:00 PM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 92 km from the middle of the area, began a volume at 01:18 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
Jun 26, 8:30 PM CDTFLASH FLOODBrunsville, IAWATER SURROUNDED TWO HOMES IN BRUNSVILLE NEAR GOLF COURSE.
Jun 26, 8:30 PM CDTFLASH FLOODLe Mars, IAQUITE A BIT OF STREET FLOODING IN TOWN.
Jun 26, 10:24 PM CDTHEAVY RAIN 0Le Mars, IA3.05 INCHES OF RAIN.

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 00:00Z, 1.3 hours before the alert went out and 168 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 2011-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2873 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2011-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 248 square meters per square second.19395878Sfc1 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
2873 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
501 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
248 m²/s²
0-3 km storm-relative helicity
308 m²/s²
Significant tornado parameter
6.2
Supercell composite
26.5

Open this sounding in Storm Lab

The text

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

783 
WGUS53 KFSD 270117
FFWFSD
IAC149-270400-
/O.NEW.KFSD.FF.W.0018.110627T0117Z-110627T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
817 PM CDT SUN JUN 26 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN PLYMOUTH COUNTY IN NORTHWEST IOWA

* UNTIL 1100 PM CDT

* AT 809 PM CDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING   
ACROSS IN BRUNSVILLE. MINK CREEK RUNNING THROUGH THE PARK IN 
BRUNSVILLE WAS FLOODING. 

* WHILE RAINFALL HAS DECREASED IN INTENSITY...MINK CREEK CAN BE 
  EXPECTED TO RISE RAPIDLY MAY CAUSE FLASH FLOODING ON MINK CREEK 
  BETWEEN BRUNSVILLE AND MERRILL.

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 4278 9637 4291 9636 4291 9613 4276 9614

$$
SCHUMACHER
2 follow-up statements
152 
WGUS73 KFSD 270241
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
941 PM CDT SUN JUN 26 2011

IAC149-270400-
/O.CON.KFSD.FF.W.0018.000000T0000Z-110627T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PLYMOUTH IA-
941 PM CDT SUN JUN 26 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHERN PLYMOUTH COUNTY
UNTIL 1100 PM CDT...

AT 937 PM CDT...DOPPLER RADAR INDICATED THAT THE RAINFALL HAD ENDED 
ACROSS THE AREA. HOWEVER...UP TO 2 INCHES OF RAIN HAD FALLEN ACROSS 
THE AREA EARLIER THIS EVENING AND CONTINUED RUNOFF MAY CAUSE FLASH 
FLOODING...ESPECIALLY IN RURAL AREAS NORTH AND WEST OF LE MARS. 

AT 830 PM CDT...PLYMOUTH COUNTY EMERGENCY MANAGER REPORTED STREET 
FLOODING IN LE MARS.  

AT 830 PM CDT...A TRAINED SPOTTER REPORTED THAT FLOODING FROM MINK 
CREEK HAD SURROUNDED TWO HOMES IN BRUNSVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY ROADS
AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING
AREAS ARE ALSO SUBJECT TO FLOODING.

&&

LAT...LON 4278 9637 4291 9636 4291 9613 4276 9614

$$
SCHUMACHER
405 
WGUS73 KFSD 270357
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1057 PM CDT SUN JUN 26 2011

IAC149-270411-
/O.EXP.KFSD.FF.W.0018.000000T0000Z-110627T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PLYMOUTH IA-
1057 PM CDT SUN JUN 26 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHERN PLYMOUTH
COUNTY WILL BE ALLOWED TO EXPIRE AT 1100 PM CDT...

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 4278 9637 4291 9636 4291 9613 4276 9614

$$

SCHUMACHER

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 7:27 PM CDTFlash Flood WarningFSDWoodbury3 hr
Jun 26, 7:29 PM CDTSevere Thunderstorm WarningFSDWoodbury31 min
Jun 26, 7:37 PM CDTSevere Thunderstorm WarningFSDIda, Woodbury38 min
Jun 26, 7:56 PM CDTFlash Flood WarningFSDCherokee, O'Brien, Plymouth, Sioux3 hr
Jun 26, 7:59 PM CDTSevere Thunderstorm WarningFSDWoodbury31 min
Jun 26, 8:14 PM CDTSevere Thunderstorm WarningFSDIda, Woodbury31 min
Jun 26, 8:21 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury24 min
Jun 26, 8:32 PM CDTSevere Thunderstorm WarningFSDCherokee28 min
Jun 26, 8:41 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury34 min
Jun 26, 8:44 PM CDTSevere Thunderstorm WarningFSDIda, Woodbury31 min
Jun 26, 8:52 PM CDTFlash Flood WarningFSDCherokee2 hr
Jun 26, 8:56 PM CDTSevere Thunderstorm WarningFSDBuena Vista34 min
Jun 26, 8:58 PM CDTHigh Wind WarningFSDBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more4 hr
Jun 26, 8:59 PM CDTSevere Thunderstorm WarningFSDCherokee31 min
Jun 26, 9:02 PM CDTFlash Flood WarningFSDBuena Vista, Clay3 hr
Jun 26, 9:29 PM CDTSevere Thunderstorm WarningFSDBuena Vista31 min
Jun 26, 10:54 PM CDTAreal Flood WarningFSDCherokee, O'Brien, Plymouth, Sioux36 hr
Jun 27, 3:16 PM CDTRiver Flood WarningFSDWoodbury42 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.