Alert archive / Iowa / Flash Flood Warnings in 2012

Flash Flood Warning 3, NWS Sioux Falls, SD

May 3, 2012Cherokee County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at May 3, 2012, 8:05 PM CDT for Cherokee County, Iowa. It was in force for 93 min. 2 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 3, 2012, 8:05 PM CDT (01:05 UTC)
Expired: May 3, 2012, 9:38 PM CDT
In force: 93 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Flood severity: None

County Cherokee County, IA

The radar

The Sioux Falls radar (KFSD), 132 km from the middle of the area, began a volume at 01:06 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

Time	Report	Where	Remark
May 3, 8:12 PM CDT	HEAVY RAIN 1	3 S Larrabee, IA	ONE INCH OF RAIN FELL IN 15 MINUTES
May 3, 8:23 PM CDT	FLASH FLOOD	4 Se Larrabee, IA	FIELDS UNDER WATER AND NICKEL SIZE HAIL AT INTERSECTION OF C25 AND M10

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, 1.1 hours before the alert went out and 179 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2202 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 1397 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

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

467 
WGUS53 KFSD 040105
FFWFSD
IAC035-040500-
/O.NEW.KFSD.FF.W.0003.120504T0105Z-120504T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
805 PM CDT THU MAY 3 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN CHEROKEE COUNTY IN NORTHWEST IOWA

* UNTIL MIDNIGHT CDT

* AT 802 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.    
  THIS STORM COULD PRODUCE RAINFALL RATES OF 3 TO 4 INCHES AN HOUR. 
  RAINFALL AMOUNTS OF 1 TO 2 INCHES HAVE BEEN ESTIMATED WITH THIS 
  STORM.
 


* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CHEROKEE AND LARRABEE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING WARNING MEANS THAT 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 4272 9563 4285 9562 4289 9539 4286 9538
      4275 9539

$$

JM

1 follow-up statement

815 
WGUS73 KFSD 040238
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
938 PM CDT THU MAY 3 2012

IAC035-040253-
/O.CAN.KFSD.FF.W.0003.000000T0000Z-120504T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHEROKEE IA-
938 PM CDT THU MAY 3 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR EASTERN CHEROKEE
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 4272 9563 4285 9562 4289 9539 4286 9538
      4275 9539

$$

JM

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 7:57 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	33 min
May 3, 8:37 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee	38 min
May 4, 3:00 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	30 min
May 4, 3:14 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Sioux	31 min
May 4, 3:18 PM CDT	Severe Thunderstorm Warning	FSD	O'Brien, Osceola, Sioux	42 min
May 4, 3:20 PM CDT	Tornado Warning	FSD	O'Brien, Sioux	25 min
May 4, 3:39 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	36 min
May 4, 3:43 PM CDT	Tornado Warning	FSD	O'Brien, Sioux	32 min
May 4, 4:01 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, O'Brien	29 min
May 4, 4:06 PM CDT	Tornado Warning	FSD	Clay	24 min
May 4, 4:09 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson, Osceola	51 min
May 4, 4:12 PM CDT	Severe Thunderstorm Warning	FSD	Clay, O'Brien	33 min
May 4, 4:25 PM CDT	Severe Thunderstorm Warning	FSD	Clay	35 min

Nearby

Flash Flood Warnings in Iowa, 2012 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.