Alert archive / South Dakota / Tornado Warnings in 2012

Tornado Warning 3, NWS Sioux Falls, SD

April 15, 2012Bon Homme County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Apr 15, 2012, 2:56 PM CDT for Bon Homme County, South Dakota. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 15, 2012, 2:56 PM CDT (19:56 UTC)
Expired
Apr 15, 2012, 3:30 PM CDT
In force
34 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon

County Bon Homme County, SD

The radar

The Sioux Falls radar (KFSD), 102 km from the middle of the area, began a volume at 19:59 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

Aberdeen, SD (KABR), launched 12:00Z, 7.9 hours before the alert went out and 213 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, Aberdeen, SD at 12:00Z on 2012-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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, Aberdeen, SD at 12:00Z on 2012-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 91 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
484 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
91 m²/s²
0-3 km storm-relative helicity
656 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

037 
WFUS53 KFSD 151956
TORFSD
SDC009-152030-
/O.NEW.KFSD.TO.W.0003.120415T1956Z-120415T2030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
256 PM CDT SUN APR 15 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  BON HOMME COUNTY IN SOUTHEAST SOUTH DAKOTA...

* UNTIL 330 PM CDT

* AT 256 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM WITH A HISTORY OF PRODUCING A
  TORNADO. THIS TORNADIC STORM WAS LOCATED NEAR TYNDALL...OR 23 MILES
  WEST OF YANKTON...AND MOVING NORTH AT 35 MPH.

* THIS TORNADIC STORM WILL BE NEAR...
  SCOTLAND AROUND 325 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4285 9774 4290 9800 4317 9785 4317 9773
      4317 9767 4316 9764 4310 9764
TIME...MOT...LOC 1956Z 199DEG 29KT 4295 9784

$$

MJF
2 follow-up statements
906 
WWUS53 KFSD 152009
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
309 PM CDT SUN APR 15 2012

SDC009-152030-
/O.CON.KFSD.TO.W.0003.000000T0000Z-120415T2030Z/
BON HOMME SD-
309 PM CDT SUN APR 15 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN BON HOMME
COUNTY UNTIL 330 PM CDT...

AT 307 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM WITH A HISTORY OF OF PRODUCING TORNADOES.  
THIS DANGEROUS STORM WAS LOCATED NEAR TYNDALL...OR 21 MILES WEST OF 
YANKTON...MOVING NORTH AT 35 MPH.

THIS DANGEROUS STORM WILL BE NEAR...
  SCOTLAND AROUND 325 PM CDT...

THE STRONGEST ROTATION WAS TRACKING JUST EAST OF TYNDALL. THIS STORM 
HAS PRODUCED BRIEF TORNADO TOUCHDOWNS IN KNOX COUNTY NEBRASKA AND 
ALSO LIKELY NEAR THE MISSOURI RIVER JUST NORTH OF SANTEE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4290 9773 4296 9795 4317 9785 4317 9767
      4316 9764 4310 9764
TIME...MOT...LOC 2007Z 199DEG 29KT 4301 9778

$$

MJF
456 
WWUS53 KFSD 152032
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
332 PM CDT SUN APR 15 2012

SDC009-152041-
/O.EXP.KFSD.TO.W.0003.000000T0000Z-120415T2030Z/
BON HOMME SD-
332 PM CDT SUN APR 15 2012

...THE TORNADO WARNING FOR NORTHEASTERN BON HOMME COUNTY HAS
EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

NON SUPERCELL TORNADOES CAN TOUCH THE GROUND WITH LITTLE ADVANCED 
WARNING. STORMS WHICH ARE MOVING UP THE JAMES RIVER VALLEY HAVE 
PRODUCED FUNNEL CLOUDS. BE VERY ALERT FOR CHANGING WEATHER 
CONDITIONS AND ANY FUTURE STATEMENTS AND WARNINGS.

LAT...LON 4290 9773 4296 9795 4317 9785 4317 9767
      4316 9764 4310 9764
TIME...MOT...LOC 2009Z 199DEG 29KT 4303 9777

$$

MJF

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 15, 11:22 AM CDTSevere Thunderstorm WarningFSDDavison, Hanson, Miner, Sanborn23 min
Apr 15, 11:45 AM CDTSevere Thunderstorm WarningFSDBeadle, Kingsbury, Miner, Sanborn45 min
Apr 15, 3:19 PM CDTSevere Thunderstorm WarningFSDBrookings, Moody16 min
Apr 15, 5:10 PM CDTHigh Wind WarningFSDAurora, Beadle, Bon Homme, Brookings, Brule, Charles Mix and 17 more11 hr
Apr 15, 5:10 PM CDTWind AdvisoryFSDAurora, Brule, Charles Mix, Douglas, Gregory, Jerauld3 hr

Nearby

Tornado Warnings in South Dakota, 2012Every tornado warning in 2012Tornadoes in 2012

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.