Alert archive / Iowa / Flash Flood Warnings in 2012

Flash Flood Warning 1, NWS Sioux Falls, SD

April 14, 2012Woodbury County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Apr 14, 2012, 11:59 PM CDT for Woodbury 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
Apr 14, 2012, 11:59 PM CDT (04:59 UTC)
Expired
Apr 15, 2012, 2:59 AM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

County Woodbury County, IA

The radar

The Omaha radar (KOAX), 124 km from the middle of the area, began a volume at 05:02 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, 5.0 hours before the alert went out and 125 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 2012-04-15Temperature 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 2012-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 276 square meters per square second.1939587897Sfc1 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
871 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
276 m²/s²
0-3 km storm-relative helicity
483 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

266 
WGUS53 KFSD 150459
FFWFSD
IAC193-151100-
/O.NEW.KFSD.FF.W.0001.120415T0459Z-120415T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1159 PM CDT SAT APR 14 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL WOODBURY COUNTY IN WEST CENTRAL IOWA

* UNTIL 600 AM CDT SUNDAY

* AT 1152 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR 
INDICATED   THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED 
AREA. RAINFALL AMOUNTS IN EXCESS OF TWO INCHES FELL ACROSS THE AREA 
EARLIER IN THE EVENING...AND WITH THUNDERSTORMS MOVING THROUGH THE 
AREA ADDITIONAL AMOUNTS OF ONE HALF TO 1 INCH OF RAINFALL WILL BE 
POSSIBLE THROUGH THE LATE NIGHT HOURS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ANTHON...HORNICK...LAWTON...MOVILLE...PIERSON...SALIX...SLOAN AND
  SMITHLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 4250 9628 4256 9625 4256 9585 4222 9586
      4222 9632

$$

JM
1 follow-up statement
806 
WGUS73 KFSD 150759
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
259 AM CDT SUN APR 15 2012

IAC193-150814-
/O.CAN.KFSD.FF.W.0001.000000T0000Z-120415T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WOODBURY IA-
259 AM CDT SUN APR 15 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL WOODBURY
COUNTY 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.

IF FLOODING WAS OBSERVED PLEASE RELAY YOUR REPORT TO LOCAL LAW
ENFORCEMENT OR TO THE NATIONAL WEATHER SERVICE IN SIOUX FALLS.

LAT...LON 4250 9628 4256 9625 4256 9585 4222 9586
      4222 9632

$$

SCHMIT

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 15, 3:26 PM CDTWind AdvisoryFSDBuena Vista, Cherokee, Clay, Dickinson, Ida, O'Brien and 1 more4 hr

Nearby

Flash Flood Warnings in Iowa, 2012Every flash flood warning in 2012

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.