Alert archive / South Dakota / Tornado Warnings in 2009

Tornado Warning 52, NWS Sioux Falls, SD

August 8, 2009Bon Homme County, Yankton County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Aug 8, 2009, 2:47 PM CDT for Bon Homme County, Yankton County, South Dakota. It was in force for 23 min. 1 report 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
Aug 8, 2009, 2:47 PM CDT (19:47 UTC)
Expired
Aug 8, 2009, 3:10 PM CDT
In force
23 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon

Counties Bon Homme County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 81 km from the middle of the area, began a volume at 19:48 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

TimeReportWhereRemark
Aug 8, 2:52 PM CDTHAIL 1.75N Lesterville, SD

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 8, 11:15 AM CDTSevere Thunderstorm WatchSPC4 hr
Aug 8, 12:47 PM CDTTornado WatchSPC5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.8 hours before the alert went out and 212 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, Omaha, NE at 12:00Z on 2009-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1128 joules per kilogram.LCLLFCEL10008507005003002001001 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, Omaha, NE at 12:00Z on 2009-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 451 square meters per square second.19395878Sfc1 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
1128 J/kg
Mixed-layer CIN
-417 J/kg
Mixed-layer LCL
1505 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
451 m²/s²
0-3 km storm-relative helicity
471 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KFSD 081947
TORFSD
SDC009-135-082030-
/O.NEW.KFSD.TO.W.0052.090808T1947Z-090808T2030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
247 PM CDT SAT AUG 8 2009

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

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

* UNTIL 330 PM CDT

* AT 244 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR TABOR...OR 16 MILES NORTHWEST OF YANKTON...
  AND MOVING EAST AT 30 MPH.

* THIS TORNADIC STORM WILL BE NEAR...
   LESTERVILLE AROUND 255 PM CDT...
   UTICA AROUND 300 PM CDT...
   MAYFIELD AROUND 320 PM CDT...

THIS REPLACES A PORTION OF THE PREVIOUS SEVERE THUNDERSTORM WARNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

&&

LAT...LON 4316 9722 4300 9718 4292 9772 4305 9777
TIME...MOT...LOC 1947Z 249DEG 26KT 4300 9765

$$

CHAPMAN
2 follow-up statements
000 
WWUS53 KFSD 082004
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
304 PM CDT SAT AUG 8 2009

SDC009-082013-
/O.CAN.KFSD.TO.W.0052.000000T0000Z-090808T2030Z/
BON HOMME SD-
304 PM CDT SAT AUG 8 2009

...THE TORNADO WARNING FOR EASTERN BON HOMME COUNTY IS CANCELLED...

THE STORM HAS MOVED EAST INTO YANKTON COUNTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CDT SATURDAY EVENING
FOR NORTHWEST IOWA AND SOUTHWEST MINNESOTA AND SOUTHEASTERN SOUTH
DAKOTA. A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 600
PM CDT SATURDAY EVENING FOR SOUTHEASTERN SOUTH DAKOTA.

LAT...LON 4294 9758 4309 9758 4316 9722 4300 9718
TIME...MOT...LOC 2003Z 248DEG 27KT 4305 9749

$$

SDC135-082030-
/O.CON.KFSD.TO.W.0052.000000T0000Z-090808T2030Z/
YANKTON SD-
304 PM CDT SAT AUG 8 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR NORTHERN
YANKTON COUNTY...

AT 259 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A TORNADO. THIS TORNADO WAS LOCATED JUST NORTHEAST OF LESTERVILLE
NEAR UTICA...OR 13 MILES NORTHWEST OF YANKTON...MOVING EAST AT 30 
MPH.

THE TORNADO WILL BE NEAR...
MAYFIELD AROUND 320 PM CDT...

AT 259 PM CDT...EMERGENCY MANAGEMENT REPORTED A RAIN FREE CLOUD BASE 
DEVELOPING NORTHEAST OF LESTERVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CDT SATURDAY EVENING
FOR NORTHWEST IOWA AND SOUTHWEST MINNESOTA AND SOUTHEASTERN SOUTH
DAKOTA. A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 600
PM CDT SATURDAY EVENING FOR SOUTHEASTERN SOUTH DAKOTA.

&&

LAT...LON 4294 9758 4309 9758 4316 9722 4300 9718
TIME...MOT...LOC 2003Z 248DEG 27KT 4305 9749

$$

CHAPMAN
000 
WWUS53 KFSD 082010
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
310 PM CDT SAT AUG 8 2009

SDC135-082020-
/O.CAN.KFSD.TO.W.0052.000000T0000Z-090808T2030Z/
YANKTON SD-
310 PM CDT SAT AUG 8 2009

...THE TORNADO WARNING FOR NORTHERN YANKTON COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND NO LONGER
APPEARED TO BE SEVERE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CDT SATURDAY EVENING
FOR NORTHWEST IOWA AND SOUTHWEST MINNESOTA AND SOUTHEASTERN SOUTH
DAKOTA. A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 600
PM CDT SATURDAY EVENING FOR SOUTHEASTERN SOUTH DAKOTA.

LAT...LON 4294 9758 4309 9758 4316 9722 4300 9718
TIME...MOT...LOC 2010Z 248DEG 27KT 4306 9742

$$

CHAPMAN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 11:09 AM CDTSevere Thunderstorm WarningFSDBrule, Charles Mix, Gregory36 min
Aug 8, 11:42 AM CDTSevere Thunderstorm WarningFSDAurora, Brule, Charles Mix, Douglas33 min
Aug 8, 12:10 PM CDTTornado WarningFSDAurora, Davison, Douglas35 min
Aug 8, 12:44 PM CDTTornado WarningFSDDavison, Hanson31 min
Aug 8, 1:12 PM CDTTornado WarningFSDHanson, Hutchinson, McCook33 min
Aug 8, 1:15 PM CDTTornado WarningFSDHanson, McCook, Miner30 min
Aug 8, 1:42 PM CDTTornado WarningFSDMcCook, Minnehaha33 min
Aug 8, 1:55 PM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix, Gregory, Hutchinson, Yankton50 min
Aug 8, 1:57 PM CDTSevere Thunderstorm WarningFSDGregory48 min
Aug 8, 1:59 PM CDTTornado WarningFSDMcCook, Minnehaha16 min
Aug 8, 2:12 PM CDTTornado WarningFSDLake, McCook, Minnehaha, Moody33 min
Aug 8, 2:25 PM CDTSevere Thunderstorm WarningFSDLake, Moody35 min
Aug 8, 2:43 PM CDTSevere Thunderstorm WarningFSDBon Homme, Hutchinson, Turner, Yankton30 min

Nearby

Tornado Warnings in South Dakota, 2009Every tornado warning in 2009Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.