Alert archive / South Dakota / Tornado Warnings in 2009

Tornado Warning 49, NWS Sioux Falls, SD

August 8, 2009McCook County, Minnehaha County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Aug 8, 2009, 1:42 PM CDT for McCook County, Minnehaha County, South Dakota. It was in force for 33 min. 5 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
Aug 8, 2009, 1:42 PM CDT (18:42 UTC)
Expired
Aug 8, 2009, 2:15 PM CDT
In force
33 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon

Counties McCook County, SD, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 37 km from the middle of the area, began a volume at 18:45 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, 1:51 PM CDTTSTM WND GST 70Canistota, SD70 MPH WIND GUSTS BREAKING SMALL BRANCHES OFF TREES.
Aug 8, 1:58 PM CDTHAIL 15 Ne Salem, SD
Aug 8, 2:05 PM CDTHAIL 1.75Montrose, SD
Aug 8, 2:08 PM CDTHAIL 1.751 W Montrose, SD
Aug 8, 2:12 PM CDTHAIL 15 Ne Montrose, 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

Aberdeen, SD (KABR), launched 12:00Z, 6.7 hours before the alert went out and 164 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 2009-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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, Aberdeen, SD at 12:00Z on 2009-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -219 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
3 J/kg
Mixed-layer CIN
-564 J/kg
Mixed-layer LCL
1478 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-219 m²/s²
0-3 km storm-relative helicity
-319 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 
WFUS53 KFSD 081842
TORFSD
SDC087-099-081915-
/O.NEW.KFSD.TO.W.0049.090808T1842Z-090808T1915Z/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL MCCOOK COUNTY IN SOUTHEAST SOUTH DAKOTA
  NORTHWESTERN MINNEHAHA COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 215 PM CDT

* AT 141 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR SALEM...OR 23 MILES NORTHWEST OF PARKER...
  AND MOVING EAST AT 35 MPH.

* THIS TORNADIC STORM WILL BE NEAR...
   CANISTOTA AROUND 150 PM CDT...
   MONTROSE...LAKE VERMILLION STATE RECREATION AREA AROUND 200 PM
   CDT...
   HUMBOLDT AROUND 210 PM CDT...
   HARTFORD...COLTON AROUND 215 PM CDT...

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 4384 9691 4362 9686 4356 9749 4378 9755
TIME...MOT...LOC 1842Z 262DEG 30KT 4367 9738

$$

WILLIAMS
2 follow-up statements
000 
WWUS53 KFSD 081856
SVSFSD

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

SDC087-099-081915-
/O.CON.KFSD.TO.W.0049.000000T0000Z-090808T1915Z/
MINNEHAHA SD-MCCOOK SD-
156 PM CDT SAT AUG 8 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 215 PM CDT FOR CENTRAL
MCCOOK AND NORTHWESTERN MINNEHAHA COUNTIES...

AT 155 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR MONTROSE...OR 20
MILES NORTH OF PARKER...MOVING EAST AT 35 MPH.

THE TORNADO WILL BE NEAR...
MONTROSE AROUND 200 PM CDT...
HUMBOLDT AROUND 210 PM CDT...

70 MPH WINDS BREAKING BRANCHES HAS BEEN REPORTED IN CANISTOTA BY A 
TRAINED SPOTTER WITH THIS STORM. IF YOU ARE IN THE PATH OF THE 
STORM...TAKE IMMEDIATE ACTION TO PROTECT LIFE AND PROPERTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
BASEBALL SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

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.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

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 4378 9748 4384 9691 4362 9687 4357 9741
TIME...MOT...LOC 1855Z 262DEG 30KT 4368 9723

$$

WILLIAMS
000 
WWUS53 KFSD 081917
SVSFSD

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

SDC087-099-081927-
/O.EXP.KFSD.TO.W.0049.000000T0000Z-090808T1915Z/
MINNEHAHA SD-MCCOOK SD-
217 PM CDT SAT AUG 8 2009

...THE TORNADO WARNING FOR CENTRAL MCCOOK AND NORTHWESTERN MINNEHAHA
COUNTIES EXPIRED AT 215 PM CDT...

THE STORM WHICH PROMPTED THE WARNING MOVED INTO THE EASTERN PART OF 
THE PREVIOUSLY WARNED AREA...AND A NEW TORNADO WARNING HAS BEEN 
ISSUED.

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 4378 9748 4384 9691 4362 9687 4357 9741
TIME...MOT...LOC 1856Z 262DEG 30KT 4368 9722

$$

WILLIAMS

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, 1:55 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
Aug 8, 2:47 PM CDTTornado WarningFSDBon Homme, Yankton23 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.