Alert archive / Iowa / Flash Flood Warnings in 2012

Flash Flood Warning 11, NWS Sioux Falls, SD

May 19, 2012Clay County, Dickinson County, O'Brien County, Iowa; Jackson County, Minnesota

NWS Sioux Falls, SD issued this flash flood warning at May 19, 2012, 10:11 PM CDT for Clay County, Dickinson County, O'Brien County, Iowa; Jackson County, Minnesota. 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
May 19, 2012, 10:11 PM CDT (03:11 UTC)
Expired
May 20, 2012, 1:00 AM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

Counties Clay County, IA, Dickinson County, IA, O'Brien County, IA, Jackson County, MN

The radar

The Sioux Falls radar (KFSD), 132 km from the middle of the area, began a volume at 03:11 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

Minneapolis, MN (KMPX), launched 00:00Z, 3.2 hours before the alert went out and 208 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, Minneapolis, MN at 00:00Z on 2012-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1062 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, Minneapolis, MN at 00:00Z on 2012-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 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
1062 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
2089 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.6

Open this sounding in Storm Lab

The text

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

334 
WGUS53 KFSD 200311
FFWFSD
IAC041-059-141-MNC063-200600-
/O.NEW.KFSD.FF.W.0011.120520T0311Z-120520T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1011 PM CDT SAT MAY 19 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DICKINSON COUNTY IN NORTHWEST IOWA
  NORTHEASTERN O'BRIEN COUNTY IN NORTHWEST IOWA
  NORTHERN CLAY COUNTY IN NORTHWEST IOWA
  SOUTHEASTERN JACKSON COUNTY IN SOUTHWEST MINNESOTA

* UNTIL 100 AM CDT

* AT 1002 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
  RADAR ESTIMATES 2 TO 4 INCHES OF RAINFALL HAS FALLEN OVER MUCH OF
  THE AREA...WITH LOCALIZED HIGHER AMOUNTS POSSIBLE. ADDITIONAL 
  RAINFALL OF 1 TO 2 INCHES IS POSSIBLE BEFORE THE HEAVIEST RAIN
  LIFTS NORTH OF THE AREA AROUND 11 PM.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  JACKSON...SPENCER...SPIRIT LAKE...ARNOLDS PARK...EVERLY...
  FOSTORIA...LAKE PARK...LAKEFIELD...MILFORD...OKOBOJI...ORLEANS...
  WAHPETON AND WEST OKOBOJI.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

&&

LAT...LON 4308 9504 4310 9545 4372 9524 4372 9488

$$
 JH

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 7:56 PM CDTSevere Thunderstorm WarningFSDCherokee, Ida, Plymouth, Woodbury38 min
May 19, 9:09 PM CDTSevere Thunderstorm WarningFSDCherokee, Ida, Plymouth, Woodbury51 min
May 19, 9:38 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Cherokee, Clay, O'Brien, Plymouth37 min

Nearby

Flash Flood Warnings in Iowa, 2012Flash Flood Warnings in Minnesota, 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.