Alert archive / Iowa / Tornado Warnings in 2009

Tornado Warning 8, NWS Sioux Falls, SD

May 6, 2009Clay County, O'Brien County, Iowa

NWS Sioux Falls, SD issued this tornado warning at May 6, 2009, 5:54 PM CDT for Clay County, O'Brien County, Iowa. It was in force for 35 min. 2 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
May 6, 2009, 5:54 PM CDT (22:54 UTC)
Expired
May 6, 2009, 6:29 PM CDT
In force
35 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon

Counties Clay County, IA, O'Brien County, IA

The radar

The Sioux Falls radar (KFSD), 124 km from the middle of the area, began a volume at 22:55 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
May 6, 6:01 PM CDTHAIL 13 Wnw Everly, IA
May 6, 6:15 PM CDTHAIL 14 Ssw Everly, IA

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

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.9 hours before the alert went out and 216 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 2009-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 174 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 2009-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 square meters per square second.193958Sfc1 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
174 J/kg
Mixed-layer CIN
-271 J/kg
Mixed-layer LCL
633 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
130 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 062254
TORFSD
IAC041-141-062345-
/O.NEW.KFSD.TO.W.0008.090506T2254Z-090506T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
554 PM CDT WED MAY 6 2009

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN CLAY COUNTY IN NORTHWEST IOWA
  EASTERN OBRIEN COUNTY IN NORTHWEST IOWA

* UNTIL 645 PM CDT

* AT 553 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR HARTLEY...OR 14 MILES WEST OF SPENCER...AND
  MOVING SOUTHEAST AT 15 MPH.

* THIS TORNADIC STORM WILL BE NEAR...
   MONETA...EVERLY AROUND 610 PM CDT...
   ROYAL...SUTHERLAND AROUND 635 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4304 9514 4296 9551 4325 9556 4326 9536
TIME...MOT...LOC 2254Z 333DEG 15KT 4320 9543

$$

BT
6 follow-up statements
000 
WWUS53 KFSD 062258
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
558 PM CDT WED MAY 6 2009

IAC041-141-062345-
/O.CON.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
OBRIEN IA-CLAY IA-
558 PM CDT WED MAY 6 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR
NORTHWESTERN CLAY AND EASTERN OBRIEN COUNTIES...

AT 556 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR HARTLEY...OR 14
MILES WEST OF SPENCER...MOVING SOUTHEAST AT 20 MPH.

THE TORNADO WILL BE NEAR...
MONETA AND EVERLY AROUND 605 PM CDT...
ROYAL AROUND 630 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
GOLFBALL 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.

&&

LAT...LON 4304 9514 4296 9551 4325 9556 4326 9537
TIME...MOT...LOC 2258Z 335DEG 16KT 4317 9542

$$

BT
000 
WWUS53 KFSD 062305
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
605 PM CDT WED MAY 6 2009

IAC041-141-062345-
/O.CON.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
OBRIEN IA-CLAY IA-
605 PM CDT WED MAY 6 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR WESTERN 
CLAY AND EASTERN OBRIEN COUNTIES...

AT 601 PM CDT...A TORNADO WAS REPORTED. THIS TORNADO WAS LOCATED NEAR
MONETA...OR 12 MILES WEST OF SPENCER...MOVING SOUTHEAST AT 20 MPH.

THE TORNADO WILL BE NEAR...
MONETA NOW...
ROYAL AROUND 625 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.

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.

&&

LAT...LON 4304 9514 4296 9551 4325 9556 4326 9537
TIME...MOT...LOC 2304Z 334DEG 17KT 4313 9539

$$


BT
000 
WWUS53 KFSD 062309
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
609 PM CDT WED MAY 6 2009

IAC041-141-062345-
/O.CON.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
OBRIEN IA-CLAY IA-
609 PM CDT WED MAY 6 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR
NORTHWESTERN CLAY AND EASTERN OBRIEN COUNTIES...

AT 606 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR MONETA...OR 12
MILES WEST OF SPENCER...MOVING SOUTHEAST AT 20 MPH.

THE TORNADO WILL BE NEAR...
ROYAL AROUND 625 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
WALNUT 
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.

THIS IS A DANGEROUS STORM...IF YOU ARE IN THE PATH OF THIS 
STORM...SEEK A STURDY PLACE OF SHELTER.

&&

LAT...LON 4304 9514 4296 9551 4325 9556 4326 9537
TIME...MOT...LOC 2309Z 334DEG 17KT 4311 9538

$$

BT
000 
WWUS53 KFSD 062312
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
612 PM CDT WED MAY 6 2009

IAC041-141-062345-
/O.CON.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
OBRIEN IA-CLAY IA-
612 PM CDT WED MAY 6 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR WESTERN
CLAY AND EASTERN OBRIEN COUNTIES...

AT 611 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR MONETA...OR 11
MILES WEST OF SPENCER...MOVING SOUTHEAST AT 20 MPH.

THE TORNADO WILL BE NEAR...
ROYAL AROUND 620 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
WALNUT 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.

&&

LAT...LON 4316 9547 4321 9532 4304 9514 4296 9551
TIME...MOT...LOC 2312Z 334DEG 18KT 4309 9536

$$

BT
000 
WWUS53 KFSD 062320
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
620 PM CDT WED MAY 6 2009

IAC141-062330-
/O.CAN.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
OBRIEN IA-
620 PM CDT WED MAY 6 2009

...THE TORNADO WARNING FOR EASTERN OBRIEN COUNTY IS CANCELLED...

LAT...LON 4315 9539 4317 9528 4304 9514 4299 9540
TIME...MOT...LOC 2320Z 334DEG 18KT 4305 9534

$$

IAC041-062345-
/O.CON.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
CLAY IA-
620 PM CDT WED MAY 6 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR WESTERN
CLAY COUNTY...

AT 616 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR ROYAL...OR 11 MILES
SOUTHWEST OF SPENCER...MOVING SOUTHEAST AT 25 MPH.

THE TORNADO WILL BE NEAR...
  RURAL WESTERN CLAY COUNTY THROUGH 630 PM CDT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

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.

&&

LAT...LON 4315 9539 4317 9528 4304 9514 4299 9540
TIME...MOT...LOC 2320Z 334DEG 22KT 4305 9534

$$

BT
000 
WWUS53 KFSD 062329
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
629 PM CDT WED MAY 6 2009

IAC041-062338-
/O.CAN.KFSD.TO.W.0008.000000T0000Z-090506T2345Z/
CLAY IA-
629 PM CDT WED MAY 6 2009

...THE TORNADO WARNING FOR WESTERN CLAY COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA...HOWEVER HAIL IS STILL POSSIBLE WITH THIS THUNDERSTORM.

A SEVERE THUNDERSTORM REMAINS IN EFFECT FOR SOUTHWESTERN CLAY COUNTY 
AND NORTHERN BUENA VISTA. 

LAT...LON 4315 9539 4317 9528 4304 9514 4299 9540
TIME...MOT...LOC 2328Z 334DEG 22KT 4301 9531

$$

BT

The office that day

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

IssuedProductOfficeCountiesLasted
May 6, 9:34 AM CDTSevere Thunderstorm WarningFSDDickinson26 min
May 6, 2:34 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury41 min
May 6, 3:07 PM CDTSevere Thunderstorm WarningFSDWoodbury23 min
May 6, 3:30 PM CDTSevere Thunderstorm WarningFSDWoodbury15 min
May 6, 5:15 PM CDTSevere Thunderstorm WarningFSDClay, Dickinson, Osceola45 min
May 6, 5:23 PM CDTTornado WarningFSDClay, Dickinson, O'Brien, Osceola52 min
May 6, 6:23 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Clay19 min

Nearby

Tornado Warnings in Iowa, 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.