Alert archive / Iowa / Flash Flood Warnings in 2007

Flash Flood Warning 13, NWS Sioux Falls, SD

May 5, 20074 counties in Iowa

NWS Sioux Falls, SD issued this flash flood warning at May 5, 2007, 11:06 PM CDT for 4 counties in Iowa. It was in force for 6 hr. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 5, 2007, 11:06 PM CDT (04:06 UTC)
Expired
May 6, 2007, 5:00 AM CDT
In force
6 hr
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Cherokee County, IA, Ida County, IA, Plymouth County, IA, Woodbury County, IA

The radar

The Sioux Falls radar (KFSD), 135 km from the middle of the area, began a volume at 04:08 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
May 6, 2:45 AM CDTFLASH FLOOD2 N Galva, IACOUNTY ROADS FLOODED
May 6, 2:45 AM CDTFLASH FLOOD5 S Aurelia, IACOUNTY ROADS FLOODED

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, 4.1 hours before the alert went out and 145 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 2007-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2431 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 2007-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.19395878Sfc1 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
2431 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1133 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
67 m²/s²
Significant tornado parameter
0.6
Supercell composite
7.3

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KFSD 060407
FFWFSD
IAC035-093-149-193-061000-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1106 PM CDT SAT MAY 5 2007

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CHEROKEE COUNTY IN NORTHWEST IOWA
  IDA COUNTY IN NORTHWEST IOWA
  PLYMOUTH COUNTY IN NORTHWEST IOWA
  WOODBURY COUNTY IN NORTHWEST IOWA

* UNTIL 500 AM CDT

* AT 1103 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A LARGE AREA OF THUNDERSTORMS OVER EASTERN NEBRASKA. THESE STORMS 
  WILL MOVE IN TO NORTHWEST IOWA...AND HAVE THE POTENTIAL TO PRODUCE
  2 TO 4 INCHES OF ADDITIONAL RAINFALL.  

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  SALIX...ANTHON...LAWTON...MOVILLE...CORRECTIONVILLE...CUSHING...
  HOLSTEIN...PIERSON...GALVA...HINTON...KINGSLEY...WASHTA...QUIMBY...
  MERRILL...LE MARS...AURELIA...CHEROKEE...REMSEN...MARCUS...
  CLEGHORN...CRAIG...STRUBLE AND LARRABEE

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

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

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. MOVE TO HIGHER GROUND.

LAT...LON 4225 9630 4225 9540 4290 9541 4291 9654

$$

08
2 follow-up statements
000 
WGUS73 KFSD 060732
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
229 AM CDT SUN MAY 6 2007

IAC035-093-149-193-061000-
CHEROKEE IA-PLYMOUTH IA-WOODBURY IA-IDA IA-
229 AM CDT SUN MAY 6 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 AM CDT FOR
IDA...WOODBURY...PLYMOUTH AND CHEROKEE COUNTIES...

AT 228 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE WARNED AREA. 
WIDESPREAD RAINFALL AMOUNTS OF THREE QUARTERS TO 1.25 INCHES HAVE 
OCCURRED...WITH UP TO 4 INCHES IN PORTIONS OF EASTERN IDA COUNTY.

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES IS LIKELY THROUGH 5 AM 
WITH THE HEAVIEST AMOUNTS IN IDA COUNTY.

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.

LAT...LON 4225 9630 4225 9540 4290 9541 4291 9654

$$

CJ
000 
WGUS73 KFSD 060954
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
452 AM CDT SUN MAY 6 2007

IAC035-093-149-193-061002-
CHEROKEE IA-PLYMOUTH IA-WOODBURY IA-IDA IA-
452 AM CDT SUN MAY 6 2007

...THE FLASH FLOOD WARNING WILL EXPIRE AT 500 AM CDT FOR IDA...
WOODBURY...PLYMOUTH AND CHEROKEE COUNTIES...

MODERATE RAINS WILL CONTINUE ACROSS THE AREA THROUGH 8 AM WITH 
ADDITIONAL ACCUMLATIONS AROUND ONE INCH. WIDESPREAD FLASH FLOODING 
IS NOT EXPECTED...HOWEVER...AREAS OF URBAN AND SMALL STREAM FLOODING 
IS EXPECTED AND A FLOOD WARNING REMAINS IN EFFECT UNTIUL 830 AM.

LAT...LON 4225 9630 4225 9540 4290 9541 4291 9654

$$

CJ

The office that day

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

IssuedProductOfficeCountiesLasted
May 5, 8:11 PM CDTSevere Thunderstorm WarningFSDWoodbury64 min
May 5, 10:10 PM CDTSevere Thunderstorm WarningFSDCherokee35 min
May 5, 10:29 PM CDTSevere Thunderstorm WarningFSDO'Brien31 min
May 5, 10:46 PM CDTHigh Wind WarningFSDDickinson, Lyon, O'Brien, Osceola, Sioux8 hr
May 6, 12:22 AM CDTFlash Flood WarningFSDBuena Vista, Clay, O'Brien6 hr

Nearby

Flash Flood Warnings in Iowa, 2007Every flash flood warning in 2007

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.