Alert archive / Iowa / Flash Flood Warnings in 2009

Flash Flood Warning 8, NWS Sioux Falls, SD

July 7, 2009Buena Vista County, Cherokee County, Plymouth County, Iowa; Union County, South Dakota

NWS Sioux Falls, SD issued this flash flood warning at Jul 7, 2009, 9:10 PM CDT for Buena Vista County, Cherokee County, Plymouth County, Iowa; Union County, South Dakota. It was in force for 3 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
Jul 7, 2009, 9:10 PM CDT (02:10 UTC)
Expired
Jul 8, 2009, 12:00 AM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

Counties Buena Vista County, IA, Cherokee County, IA, Plymouth County, IA, Union County, SD

The radar

The Sioux Falls radar (KFSD), 107 km from the middle of the area, began a volume at 02:14 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
Jul 7, 9:20 PM CDTFLASH FLOODAkron, IASTREET FLOODING

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, 2.2 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 00:00Z on 2009-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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 00:00Z on 2009-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
27 J/kg
Mixed-layer CIN
-201 J/kg
Mixed-layer LCL
2298 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
157 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.

000 
WGUS53 KFSD 080210
FFWFSD
IAC021-035-149-SDC127-080500-
/O.NEW.KFSD.FF.W.0008.090708T0210Z-090708T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
910 PM CDT TUE JUL 7 2009

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BUENA VISTA COUNTY IN NORTHWEST IOWA
  CENTRAL UNION COUNTY IN SOUTHEAST SOUTH DAKOTA
  CHEROKEE COUNTY IN NORTHWEST IOWA
  PLYMOUTH COUNTY IN NORTHWEST IOWA

* UNTIL MIDNIGHT CDT

* AT 907 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL MOVING SOUTHEAST INTO THE
  WARNED AREA. LOCALLY HEAVY AMOUNTS OF 2 TO 3 INCHES CAN BE EXPECTED
  IN A SHORT TIME.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...LE
  MARS...STORM LAKE...AKRON...ALBERT CITY...ALTA...AURELIA...
  CHEROKEE...ELK POINT...HINTON...JEFFERSON...KINGSLEY...LAKESIDE...
  MERRILL...NEWELL...QUIMBY...REMSEN...TRUESDALE...UNION COUNTY STATE
  PARK AND WASHTA.

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 4257 9493 4255 9665 4262 9672 4266 9670
      4267 9677 4270 9680 4294 9682 4291 9649
      4281 9648 4281 9492

$$

CJ
2 follow-up statements
000 
WGUS73 KFSD 080310
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1010 PM CDT TUE JUL 7 2009

IAC021-035-149-SDC127-080500-
/O.CON.KFSD.FF.W.0008.000000T0000Z-090708T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHEROKEE IA-PLYMOUTH IA-BUENA VISTA IA-UNION SD-
1010 PM CDT TUE JUL 7 2009

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN UNION...BUENA
VISTA...PLYMOUTH AND CHEROKEE COUNTIES UNTIL MIDNIGHT CDT...

AT 1008 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL MOVING SOUTH ACROSS THE 
WARNED AREA. DOPPLER RADAR ESTIMATED OF 1 TO 3 INCHES HAVE OCCURRED 
IN THE WARNED AREA...WITH AN ADDITIONAL 1 TO 2 INCHES OF RAIN LIKELY 
THROUGH MIDNIGHT.

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...LE MARS...STORM LAKE...AKRON...ALBERT CITY...ALTA...
AURELIA...CHEROKEE...ELK POINT...HINTON...JEFFERSON...KINGSLEY...
LAKESIDE...MERRILL...NEWELL...QUIMBY...REMSEN...TRUESDALE...UNION
COUNTY STATE PARK AND WASHTA.

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 9493 4255 9665 4262 9672 4266 9670
      4267 9677 4270 9680 4294 9682 4291 9649
      4281 9648 4281 9492

$$
CJ
000 
WGUS73 KFSD 080454
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1154 PM CDT TUE JUL 7 2009

IAC021-035-149-SDC127-080507-
/O.EXP.KFSD.FF.W.0008.000000T0000Z-090708T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHEROKEE IA-PLYMOUTH IA-BUENA VISTA IA-UNION SD-
1154 PM CDT TUE JUL 7 2009

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN UNION...
BUENA VISTA...PLYMOUTH AND CHEROKEE COUNTIES WILL BE ALLOWED TO
EXPIRE AT MIDNIGHT CDT...

THE HEAVIEST RAINS HAVE MOVED OUT OF THE WARNED AREA. 
HOWEVER...LIGHT TO MODERATE RAIN WILL PERSIST THROUGH 1 AM. THE 
THREAT OF FLASH FLOODING HAS DIMINISHED. HOWEVER...PERSONS LIVING 
ALONG RIVERS AND STREAMS SHOULD BE AWARE THAT THEY MAY RISE AND 
POSSIBLY FLOOD LATER TONIGHT. 


LAT...LON 4257 9493 4255 9665 4262 9672 4266 9670
      4267 9677 4270 9680 4294 9682 4291 9649
      4281 9648 4281 9492

$$

CJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 7:51 PM CDTSevere Thunderstorm WarningFSDLyon, Sioux39 min
Jul 7, 8:02 PM CDTSevere Thunderstorm WarningFSDSioux43 min
Jul 7, 8:23 PM CDTSevere Thunderstorm WarningFSDClay, O'Brien52 min
Jul 7, 8:39 PM CDTFlash Flood WarningFSDBuena Vista, Cherokee, Clay, O'Brien, Plymouth, Sioux3 hr
Jul 7, 8:39 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Clay51 min
Jul 7, 8:44 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux46 min
Jul 7, 8:58 PM CDTSevere Thunderstorm WarningFSDSioux32 min
Jul 7, 9:53 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury37 min
Jul 7, 10:14 PM CDTFlash Flood WarningFSDIda, Woodbury3 hr
Jul 7, 10:22 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury38 min
Jul 8, 2:12 AM CDTFlash Flood WarningFSDPlymouth, Woodbury3 hr
Jul 7, 7:32 PM CDTSevere Thunderstorm WarningFSDBeadle, Kingsbury, Miner, Sanborn43 min
Jul 7, 7:56 PM CDTFlash Flood WarningFSDLincoln, Minnehaha2 hr
Jul 7, 7:57 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha, Turner33 min
Jul 7, 8:23 PM CDTTornado WarningFSDKingsbury, Miner, Sanborn29 min
Jul 7, 8:51 PM CDTTornado WarningFSDMiner24 min
Jul 7, 9:14 PM CDTSevere Thunderstorm WarningFSDBeadle, Miner, Sanborn46 min
Jul 7, 9:58 PM CDTSevere Thunderstorm WarningFSDDavison, Hanson, McCook, Miner, Sanborn47 min
Jul 7, 10:07 PM CDTFlash Flood WarningFSDClay, Yankton88 min
Jul 7, 10:49 PM CDTSevere Thunderstorm WarningFSDUnion41 min

Nearby

Flash Flood Warnings in Iowa, 2009Flash Flood Warnings in South Dakota, 2009Every flash flood warning in 2009

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.