Alert archive / Iowa / Flash Flood Warnings in 2012

Flash Flood Warning 16, NWS Sioux Falls, SD

June 20, 2012Buena Vista County, Ida County, Woodbury County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Jun 20, 2012, 4:54 PM CDT for Buena Vista County, Ida County, Woodbury County, Iowa. It was in force for 2 hr. 1 report 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 20, 2012, 4:54 PM CDT (21:54 UTC)
Expired
Jun 20, 2012, 7:02 PM CDT
In force
2 hr
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

Counties Buena Vista County, IA, Ida County, IA, Woodbury County, IA

The radar

The Omaha radar (KOAX), 155 km from the middle of the area, began a volume at 21:56 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 20, 5:50 PM CDTFLASH FLOOD5 Sw Ida Grove, IASOME FARM FIELDS FLOODED DUE TO HEAVY RAIN. HAD 3.8 INCHES OF RAIN THROUGH 645 PM...MOST FELL BEFORE 6 PM.

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 12:00Z, 9.9 hours before the alert went out and 155 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 2012-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1133 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 2012-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 379 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
1133 J/kg
Mixed-layer CIN
-263 J/kg
Mixed-layer LCL
898 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
379 m²/s²
0-3 km storm-relative helicity
419 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

317 
WGUS53 KFSD 202154
FFWFSD
IAC021-093-193-210100-
/O.NEW.KFSD.FF.W.0016.120620T2154Z-120621T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
454 PM CDT WED JUN 20 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  IDA COUNTY IN WEST CENTRAL IOWA
  SOUTHEASTERN WOODBURY COUNTY IN WEST CENTRAL IOWA
  SOUTHERN BUENA VISTA COUNTY IN NORTHWEST IOWA

* UNTIL 800 PM CDT

* AT 446 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
RAINFALL ESTIMATES OF 2 TO 4 INCHES HAVE FALLEN ACROSS THE WARNED 
AREA. A REPORT FROM DANBURY INDICATED NEARLY FOUR INCHES OF 
RAINFALL.  AN ADDITIONAL ONE TO TWO INCHES OF RAINFALL IS EXPECTED 
ACROSS THE WARNED AREA...CREATING FLASH FLOODING. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...IDA
  GROVE...STORM LAKE...ALBERT CITY...ARTHUR...BATTLE CREEK...
  DANBURY...GALVA...HOLSTEIN...LAKESIDE...NEWELL AND SMITHLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL 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 SUBJECT TO FLOODING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4257 9544 4256 9539 4260 9538 4289 9490
      4256 9491 4255 9538 4249 9538 4247 9531
      4222 9531 4220 9534 4220 9607

$$

BT
2 follow-up statements
951 
WGUS73 KFSD 202244
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
544 PM CDT WED JUN 20 2012

IAC021-093-193-210100-
/O.CON.KFSD.FF.W.0016.000000T0000Z-120621T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
IDA IA-BUENA VISTA IA-WOODBURY IA-
544 PM CDT WED JUN 20 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHEASTERN WOODBURY...
SOUTHERN BUENA VISTA AND IDA COUNTIES UNTIL 800 PM CDT...

AT 537 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
RAINFALL REPORTS OF TWO TO FOUR INCHES OF RAINFALL HAVE FALLEN 
ACROSS THE WARNED AREA. SPECIFICALLY...2.75 INCHES WAS REPORTED IN 
IDA GROVE AND 3.96 INCHES WERE REPORTED IN DANBURY.  ALTHOUGH 
RAINFALL RATES ARE DECREASING ACROSS THE WARNED AREA...ADDITIONAL 
THUNDERSTORMS HAVE DEVELOPED UPSTREAM AND ARE EXPECTED TO MOVE 
ACROSS THE AREA IN THE NEXT FEW HOURS.  AN ADDITIONAL ONE TO TWO 
INCHES OF RAINFALL IS EXPECTED ACROSS THE WARNED AREA...LEADING TO 
FLASH FLOODING. 

SLOW MOVING THUNDERSTORMS ARE PRODUCING VERY HEAVY RAINFALL IN THE
WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH
FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING
INCLUDE...IDA GROVE...STORM LAKE...ALBERT CITY...ARTHUR...BATTLE
CREEK...DANBURY...GALVA...HOLSTEIN...LAKESIDE...NEWELL AND SMITHLAND.

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.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4257 9544 4256 9539 4260 9538 4289 9490
      4256 9491 4255 9538 4249 9538 4247 9531
      4222 9531 4220 9534 4220 9607

$$

BT
277 
WGUS73 KFSD 210002
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
702 PM CDT WED JUN 20 2012

IAC021-093-193-210014-
/O.CAN.KFSD.FF.W.0016.000000T0000Z-120621T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
IDA IA-BUENA VISTA IA-WOODBURY IA-
702 PM CDT WED JUN 20 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN
WOODBURY...SOUTHERN BUENA VISTA AND IDA COUNTIES IS CANCELLED...

WHILE RAINFALL IS EXPECTED TO CONTINUE ACROSS THE WARNED AREA FOR 
THE NEXT FEW HOURS...IT IS NOT EXPECTED TO BE HEAVY ENOUGH TO LEAD 
TO ADDITIONAL FLOODING.

FIVE MILES SOUTH OF IDA GROVE...A TRAINED SPOTTER REPORTED 3.8 
INCHES OF RAIN LEADING TO FLOODING IN LOCAL FARM FIELDS.  

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 4257 9544 4256 9539 4260 9538 4289 9490
      4256 9491 4255 9538 4249 9538 4247 9531
      4222 9531 4220 9534 4220 9607

$$


BT

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.