Alert archive / South Dakota / Flash Flood Warnings in 2011

Flash Flood Warning 29, NWS Sioux Falls, SD

July 27, 2011Lincoln County, Minnehaha County, South Dakota

NWS Sioux Falls, SD issued this flash flood warning at Jul 27, 2011, 3:56 AM CDT for Lincoln County, Minnehaha County, South Dakota. It was in force for 3 hr. 13 reports 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 27, 2011, 3:56 AM CDT (08:56 UTC)
Expired: Jul 27, 2011, 6:30 AM CDT
In force: 3 hr
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Flood severity: None

Counties Lincoln County, SD, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 11 km from the middle of the area, began a volume at 08:58 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
Jul 27, 4:10 AM CDT	FLASH FLOOD	3 Ese Sioux Falls, SD	WATER REPORTED OVER CURB AND SIDEWALK ON SOUTHEAST SIDE OF SIOUX FALLS.
Jul 27, 4:10 AM CDT	FLASH FLOOD	3 Ese Sioux Falls, SD	WATER REPORTED OVER CURB AND SIDEWALK ON SOUTHEAST SIDE OF SIOUX FALLS.
Jul 27, 4:30 AM CDT	FLASH FLOOD	Sioux Falls, SD	NUMBEROUS CITY STREETS UNDERWATER AND IMPASSABLE
Jul 27, 4:30 AM CDT	FLASH FLOOD	Sioux Falls, SD	NUMBEROUS CITY STREETS UNDERWATER AND IMPASSABLE
Jul 27, 4:32 AM CDT	FLASH FLOOD	4 Wsw Sioux Falls, SD	3.70 INCHES OF RAIN IN SOUTHWEST SIOUX FALLS IN LESS THAN 2 HOURS.
Jul 27, 4:32 AM CDT	FLASH FLOOD	4 Wsw Sioux Falls, SD	3.70 INCHES OF RAIN IN SOUTHWEST SIOUX FALLS IN LESS THAN 2 HOURS.
Jul 27, 4:32 AM CDT	FLASH FLOOD	5 Sw Sioux Falls, SD	3.70 INCHES OF RAIN IN SOUTHWEST SIOUX FALLS IN LESS THAN 2 HOURS.
Jul 27, 4:41 AM CDT	FLASH FLOOD	Sioux Falls, SD	SIGNIFICANT URBAN FLOODING IN SIOUX FALLS. SEVERAL CARS STRANDED. POLICE AND RESCUE HAD DIFFICULTY REACHING STRANDED MOTORISTS.
Jul 27, 4:41 AM CDT	FLASH FLOOD	Sioux Falls, SD	SIGNIFICANT URBAN FLOODING IN SIOUX FALLS.SEVERAL CARS STRANDED. POLICE AND RESCUE HAD DIFFICULTY REACHING STRANDED MOTORISTS.
Jul 27, 5:00 AM CDT	FLASH FLOOD	3 Se Sioux Falls, SD	4.95 INCHES OF RAIN
Jul 27, 5:00 AM CDT	FLASH FLOOD	3 Se Sioux Falls, SD	4.95 INCHES OF RAIN
Jul 27, 6:29 AM CDT	FLASH FLOOD	3 Se Sioux Falls, SD	5.75 INCHES OF RAIN IN SOUTHEAST SIOUX FALLS. 41ST STREET AND BAHNSON AVENUE WITH WATER OVER THE CURB.
Jul 27, 6:29 AM CDT	FLASH FLOOD	3 Se Sioux Falls, SD	5.75 INCHES OF RAIN IN SOUTHEAST SIOUX FALLS. 41ST STREET AND BAHNSON AVENUE WITH WATER OVER THE CURB.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 8.9 hours before the alert went out and 208 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: 3555 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 900 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 289 m²/s²
0-3 km storm-relative helicity: 399 m²/s²
Significant tornado parameter: 7.2
Supercell composite: 32.6

Open this sounding in Storm Lab

The text

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

689 
WGUS53 KFSD 270856
FFWFSD
SDC083-099-271030-
/O.NEW.KFSD.FF.W.0029.110727T0856Z-110727T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
356 AM CDT WED JUL 27 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN LINCOLN COUNTY IN SOUTHEAST SOUTH DAKOTA
  SOUTHERN MINNEHAHA COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 530 AM CDT

* AT 353 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.     
  TUNDERSTORMS ARE PRODUCING UP TO 2 INCHES OF RAIN PER HOUR.   

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...SIOUX
  FALLS...BRANDON...CROOKS...ROWENA AND TEA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

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 4353 9653 4350 9656 4350 9660 4349 9659
      4347 9659 4344 9662 4344 9685 4367 9684
      4368 9651

$$

LIEBL

3 follow-up statements

440 
WGUS73 KFSD 270917
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
417 AM CDT WED JUL 27 2011

SDC083-099-271030-
/O.CON.KFSD.FF.W.0029.000000T0000Z-110727T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MINNEHAHA SD-LINCOLN SD-
417 AM CDT WED JUL 27 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHERN LINCOLN AND
SOUTHERN MINNEHAHA COUNTIES UNTIL 530 AM CDT...

AT 414 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. THE 
SIOUX FALLS AIRPORT HAS HAD 2.20 INCHES OF RAIN SINCE 310 AM 
CDT...WITH RAINFALL RATES APPROACHING 4 INCHES PER HOUR. THIS HEAVY 
RAINFALL WILL CAUSE FLOODING IN POOR DRAINAGE AREAS.

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...SIOUX FALLS...BRANDON...CROOKS...ROWENA AND TEA.

AT 410 AM CDT...AN OFF DUTY NATIONAL WEATHER SERVICE EMPLOYEE 
REPORTED WATER FLOWING OVER THE CURB AND ONTO SIDEWALKS ON THE 
SOUTHEAST SIDE OF SIOUX FALLS. 

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 4353 9653 4350 9656 4350 9660 4349 9659
      4347 9659 4344 9662 4344 9685 4367 9684
      4368 9651

$$

SCHUMACHER

365 
WGUS53 KFSD 270938
FFWFSD
SDC083-099-271130-
/O.EXT.KFSD.FF.W.0029.000000T0000Z-110727T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
438 AM CDT WED JUL 27 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  NORTHERN LINCOLN COUNTY IN SOUTHEAST SOUTH DAKOTA
  SOUTHERN MINNEHAHA COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 630 AM CDT

* AT 434 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 3.70 
INCHES OF RAIN WAS REPORTED IN SOUTHWEST SIOUX FALLS FROM THESE 
STORMS IN LESS THAN 2 HOURS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...SIOUX
  FALLS...BRANDON...CROOKS...ROWENA AND TEA.

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.

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT OR IN A VEHICLE.

&&

LAT...LON 4353 9653 4350 9656 4350 9660 4349 9659
      4347 9659 4344 9662 4344 9685 4367 9684
      4368 9651

$$

LIEBL

570 
WGUS73 KFSD 271122
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
622 AM CDT WED JUL 27 2011

SDC083-099-271135-
/O.EXP.KFSD.FF.W.0029.000000T0000Z-110727T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MINNEHAHA SD-LINCOLN SD-
622 AM CDT WED JUL 27 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHERN LINCOLN
AND SOUTHERN MINNEHAHA COUNTIES WILL BE ALLOWED TO EXPIRE AT 630 AM
CDT...

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 4353 9653 4350 9656 4350 9660 4349 9659
      4347 9659 4344 9662 4344 9685 4367 9684
      4368 9651

$$

LIEBL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 8:07 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Jerauld	38 min
Jul 26, 8:41 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	49 min
Jul 26, 9:02 PM CDT	Tornado Warning	FSD	Beadle	14 min
Jul 26, 9:23 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Jerauld, Kingsbury, Miner, Sanborn	36 min
Jul 26, 10:03 PM CDT	Severe Thunderstorm Warning	FSD	Jerauld	42 min
Jul 26, 10:18 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Jerauld, Miner, Sanborn	42 min
Jul 26, 10:54 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Brookings, Kingsbury, Lake, Miner, Sanborn	40 min
Jul 26, 11:42 PM CDT	Severe Thunderstorm Warning	FSD	Lake, McCook, Minnehaha	33 min
Jul 27, 12:16 AM CDT	Severe Thunderstorm Warning	FSD	McCook, Minnehaha	44 min
Jul 27, 4:17 AM CDT	Flash Flood Warning	FSD	Minnehaha	2 hr
Jul 27, 7:02 AM CDT	River Flood Warning	FSD	Lincoln, Minnehaha	3 hr
Jul 27, 9:39 AM CDT	River Flood Warning	FSD	Lincoln, Union	3 days
Jul 27, 9:39 AM CDT	River Flood Warning	FSD	Union	4 days
Jul 27, 2:49 PM CDT	River Flood Warning	FSD	Minnehaha	19 hr

Nearby

Flash Flood Warnings in South Dakota, 2011 Every flash flood warning in 2011

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.