Alert archive / Minnesota / Flash Flood Warnings in 2011

Flash Flood Warning 30, NWS Sioux Falls, SD

July 27, 2011Minnehaha County, South Dakota; Lyon County, Iowa; Nobles County, Rock County, Minnesota

NWS Sioux Falls, SD issued this flash flood warning at Jul 27, 2011, 4:17 AM CDT for Minnehaha County, South Dakota; Lyon County, Iowa; Nobles County, Rock County, Minnesota. 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: Jul 27, 2011, 4:17 AM CDT (09:17 UTC)
Expired: Jul 27, 2011, 6:30 AM CDT
In force: 2 hr
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Flood severity: None

Counties Lyon County, IA, Nobles County, MN, Rock County, MN, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 33 km from the middle of the area, began a volume at 09:21 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

Aberdeen, SD (KABR), launched 00:00Z, 9.3 hours before the alert went out and 224 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.

105 
WGUS53 KFSD 270917
FFWFSD
IAC119-MNC105-133-SDC099-271130-
/O.NEW.KFSD.FF.W.0030.110727T0917Z-110727T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN MINNEHAHA COUNTY IN SOUTHEAST SOUTH DAKOTA
  NORTHERN LYON COUNTY IN NORTHWEST IOWA
  ROCK COUNTY IN SOUTHWEST MINNESOTA
  WESTERN NOBLES COUNTY IN SOUTHWEST MINNESOTA

* UNTIL 630 AM CDT

* AT 411 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.     
  RAINFALL RATES IN EXCESS OF 2 INCHES PER HOUR HAVE BEEN OCCURING   
  WITH THESE THUNDERSTORMS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  LUVERNE...ROCK RAPIDS...ADRIAN...ALVORD...BEAVER CREEK...BLUE
  MOUNDS STATE PARK...ELLSWORTH...GARRETSON...HARDWICK...HILLS...
  LARCHWOOD...LESTER...LISMORE...LITTLE ROCK...PALISADES STATE
  PARK...SHERMAN AND VALLEY SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

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

&&

LAT...LON 4339 9587 4330 9653 4331 9652 4334 9654
      4340 9652 4340 9655 4385 9652 4385 9641
      4385 9640 4385 9582

$$

LIEBL

1 follow-up statement

400 
WGUS73 KFSD 271037
FFSFSD

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

IAC119-MNC105-133-SDC099-271130-
/O.CON.KFSD.FF.W.0030.000000T0000Z-110727T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LYON IA-NOBLES MN-ROCK MN-MINNEHAHA SD-
537 AM CDT WED JUL 27 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR EASTERN MINNEHAHA...
ROCK...WESTERN NOBLES AND NORTHERN LYON COUNTIES UNTIL 630 AM CDT...

AT 534 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
DOPPLER RADAR ESTIMATED 3 TO 4 INCHES OF RAIN IN LESS THAN 2 HOURS 
IN SOUTHWESTERN ROCK COUNTY. 

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...LUVERNE...ROCK RAPIDS...ADRIAN...ALVORD...BEAVER CREEK...
BLUE MOUNDS STATE PARK...ELLSWORTH...GARRETSON...HARDWICK...HILLS...
LARCHWOOD...LESTER...LISMORE...LITTLE ROCK...PALISADES STATE PARK...
SHERMAN AND VALLEY SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD RELATED DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO
CROSS BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS THE
ROADWAY. NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON
FOOT OR IN A VEHICLE.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

&&

LAT...LON 4339 9587 4330 9653 4331 9652 4334 9654
      4340 9652 4340 9655 4354 9655 4355 9654
      4384 9652 4385 9640 4385 9582

$$

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, 3:56 AM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha	3 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
Jul 27, 5:02 AM CDT	Flash Flood Warning	FSD	Osceola	3 hr

Nearby

Flash Flood Warnings in Minnesota, 2011 Flash Flood Warnings in South Dakota, 2011 Flash Flood Warnings in Iowa, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.