Alert archive / Iowa / Flash Flood Warnings in 2009

Flash Flood Warning 2, NWS Sioux Falls, SD

March 23, 2009Union County, South Dakota; Plymouth County, Woodbury County, Iowa; Dakota County, Dixon County, Nebraska

NWS Sioux Falls, SD issued this flash flood warning at Mar 23, 2009, 4:57 PM CDT for Union County, South Dakota; Plymouth County, Woodbury County, Iowa; Dakota County, Dixon County, Nebraska. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Mar 23, 2009, 4:57 PM CDT (21:57 UTC)
Expired: Mar 23, 2009, 6:59 PM CDT
In force: 2 hr
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Flood severity: None

Counties Plymouth County, IA, Woodbury County, IA, Dakota County, NE, Dixon County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 122 km from the middle of the area, began a volume at 21:59 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.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.0 hours before the alert went out and 132 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: 1023 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 504 m²/s²
0-3 km storm-relative helicity: 539 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 232157
FFWFSD
IAC149-193-NEC043-051-SDC127-240000-
/O.NEW.KFSD.FF.W.0002.090323T2157Z-090324T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
457 PM CDT MON MAR 23 2009

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DAKOTA COUNTY IN NORTHEAST NEBRASKA
  NORTHEASTERN DIXON COUNTY IN NORTHEAST NEBRASKA
  SOUTHERN UNION COUNTY IN SOUTHEAST SOUTH DAKOTA
  SOUTHWESTERN PLYMOUTH COUNTY IN NORTHWEST IOWA
  WESTERN WOODBURY COUNTY IN NORTHWEST IOWA

* UNTIL 700 PM CDT

* AT 450 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS WITH VERY HEAVY RAINFALL MOVING INTO THE WARNED
  AREA. RAINFALL AMOUNTS OF UP TO AN INCH CAN BE EXPECTED IN A 15 TO 
  30 MINUTE PERIOD.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  PONCA...SIOUX CITY...DAKOTA CITY...ELK POINT...HOMER...HUBBARD...
  JACKSON...JEFFERSON...NORTH SIOUX CITY...PONCA STATE PARK...
  SALIX...SERGEANT BLUFF...SOUTH SIOUX CITY AND STONE STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

&&

LAT...LON 4227 9658 4270 9683 4273 9681 4273 9637
      4228 9608

$$
BUSS

2 follow-up statements

000 
WGUS73 KFSD 232328
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
628 PM CDT MON MAR 23 2009

IAC149-193-NEC043-051-SDC127-240000-
/O.CON.KFSD.FF.W.0002.000000T0000Z-090324T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PLYMOUTH IA-WOODBURY IA-DAKOTA NE-DIXON NE-UNION SD-
628 PM CDT MON MAR 23 2009

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN UNION...
NORTHEASTERN DIXON...DAKOTA...WESTERN WOODBURY AND SOUTHWESTERN
PLYMOUTH COUNTIES UNTIL 700 PM CDT...

AT 618 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
DOPPLER RADAR ESTIMATED BETWEEN HALF AN INCH TO AN INCH HAVE FALLEN
IN THE WARNED AREA. THE THUNDERSTORMS WERE BEGINNING TO MOVE OFF TO 
THE NORTH OUT OF THE SIOUX CITY AREA...LITTLE ADDITIONAL RAINFALL IS 
EXPECTED.

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...PONCA...SIOUX CITY...DAKOTA CITY...ELK POINT...HOMER...
HUBBARD...JACKSON...JEFFERSON...NORTH SIOUX CITY...PONCA STATE
PARK...SALIX...SERGEANT BLUFF...SOUTH SIOUX CITY AND STONE STATE
PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE MINOR FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

&&

LAT...LON 4227 9658 4270 9683 4273 9681 4273 9637
      4228 9608

$$
BUSS

000 
WGUS73 KFSD 232359
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
659 PM CDT MON MAR 23 2009

IAC149-193-NEC043-051-SDC127-240011-
/O.CAN.KFSD.FF.W.0002.000000T0000Z-090324T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PLYMOUTH IA-WOODBURY IA-DAKOTA NE-DIXON NE-UNION SD-
659 PM CDT MON MAR 23 2009

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN UNION...
NORTHEASTERN DIXON...DAKOTA...WESTERN WOODBURY AND SOUTHWESTERN
PLYMOUTH COUNTIES IS CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. URBAN 
ROADWAYS AND LOW LYING AREAS 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 4227 9658 4270 9683 4273 9681 4273 9637
      4228 9608

$$
BUSS

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 22, 7:12 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, Hutchinson, McCook	33 min
Mar 22, 8:41 PM CDT	Flash Flood Warning	FSD	Brookings, Kingsbury, Lake, Miner	3 hr
Mar 23, 11:11 AM CDT	River Flood Warning	FSD	Hutchinson, Yankton	83 days
Mar 23, 3:34 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	41 min
Mar 23, 4:08 PM CDT	Tornado Warning	FSD	Bon Homme	37 min
Mar 23, 4:12 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Douglas, Gregory	38 min
Mar 23, 4:34 PM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Charles Mix, Douglas, Hutchinson	26 min
Mar 23, 4:53 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	52 min
Mar 23, 4:59 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Turner, Yankton	31 min
Mar 23, 5:03 PM CDT	Severe Thunderstorm Warning	FSD	Davison, Hanson, Hutchinson, McCook	27 min
Mar 23, 5:33 PM CDT	Severe Thunderstorm Warning	FSD	Hutchinson, McCook, Turner, Yankton	42 min
Mar 23, 5:36 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	24 min
Mar 23, 5:44 PM CDT	Severe Thunderstorm Warning	FSD	Union	31 min
Mar 23, 5:59 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Lincoln, Turner, Union	46 min
Mar 23, 6:09 PM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha, Turner	111 min
Mar 23, 6:17 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Union	43 min
Mar 23, 6:33 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	27 min
Mar 23, 6:44 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	46 min
Mar 23, 8:41 AM CDT	River Flood Warning	FSD	Buena Vista	3 hr

Nearby

Flash Flood Warnings in Iowa, 2009 Flash Flood Warnings in Nebraska, 2009 Flash Flood Warnings in South Dakota, 2009 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.