Alert archive / Iowa / Flash Flood Warnings in 2007

Flash Flood Warning 4, NWS Sioux Falls, SD

March 31, 2007Sioux County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Mar 31, 2007, 3:51 PM CDT for Sioux County, Iowa. It was in force for 3 hr. 1 report 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: Mar 31, 2007, 3:51 PM CDT (20:51 UTC)
Expired: Mar 31, 2007, 6:45 PM CDT
In force: 3 hr
Issued by: NWS Sioux Falls, SD
Area: Whole counties

County Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 72 km from the middle of the area, began a volume at 20:53 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
Mar 31, 6:00 PM CDT	FLASH FLOOD	Hawarden, IA	HEAVY RAIN OF 3 INCHES CAUSED FLOODING OF BASEMENT

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, 8.9 hours before the alert went out and 197 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 523 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 252 m²/s²
0-3 km storm-relative helicity: 288 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 312051
FFWFSD
IAC167-312345-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
351 PM CDT SAT MAR 31 2007

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WESTERN SIOUX COUNTY IN NORTHWEST IOWA

* UNTIL 645 PM CDT

* AT 348 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM THUNDERSTORMS ALONG A LINE EXTENDING FROM 10
  MILES WEST OF ROCK VALLEY TO 40 MILES SOUTH OF MAURICE...OR ALONG A
  LINE EXTENDING FROM 6 MILES SOUTHEAST OF CANTON TO 17 MILES
  SOUTHEAST OF SIOUX CITY...MOVING NORTHWEST AT 25 MPH.

* THE STORMS PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN OVER
  MAINLY RURAL AREAS OF THE INDICATED COUNTY.

ADDITIONAL RAINFALL AMOUNTS OF AN INCH TO AN INCH AND A HALF ARE 
POSSIBLE IN THE WARNED AREA. ESTIMATED RAINFALL THROUGH 300 PM CDT 
FOR THIS AREA IS AROUND AN INCH AND A HALF.

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. MOVE TO HIGHER GROUND.

LAT...LON 4292 9616 4293 9651 4315 9643 4326 9653
      4325 9627

$$

08

1 follow-up statement

000 
WGUS73 KFSD 312219
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
516 PM CDT SAT MAR 31 2007

IAC167-312345-
SIOUX IA-
516 PM CDT SAT MAR 31 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR
WESTERN SIOUX COUNTY...

AT 516 PM CDT...SHOWERS AND A FEW HEAVY THUNDERSTORMS SHOULD 
CONTINUE IN THE AREA THROUGH EARLY EVENING.

ADDITIONAL RAINFALL AMOUNTS OF ONE HALF TO ONE INCH ARE POSSIBLE IN 
THE WARNED AREA.

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.

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 4292 9616 4293 9651 4315 9643 4326 9653
      4325 9627

$$
RSR

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 30, 11:38 PM CDT	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Lyon, O'Brien and 2 more	4 hr
Mar 31, 2:45 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	30 min
Mar 31, 3:13 PM CDT	Flash Flood Warning	FSD	Woodbury	4 hr
Mar 31, 3:18 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	42 min
Mar 31, 3:27 PM CDT	Flash Flood Warning	FSD	Plymouth	4 hr
Mar 31, 4:47 PM CDT	Severe Thunderstorm Warning	FSD	O'Brien	22 min
Mar 31, 4:51 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	23 min

Nearby

Flash Flood Warnings in Iowa, 2007 Every 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.