Alert archive / South Dakota / Tornado Warnings in 2011

Tornado Warning 8, NWS Rapid City, SD

May 9, 2011Haakon County, South Dakota

NWS Rapid City, SD issued this tornado warning at May 9, 2011, 10:00 PM MDT for Haakon County, South Dakota. It was in force for 30 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: May 9, 2011, 10:00 PM MDT (04:00 UTC)
Expired: May 9, 2011, 10:30 PM MDT
In force: 30 min
Issued by: NWS Rapid City, SD
Area: Storm-based polygon

County Haakon County, SD

The radar

The Rapid City radar (KUDX), 129 km from the middle of the area, began a volume at 04:03 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

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

Issued	Product	Office	Lasted
Mar 3, 10:24 PM MST	Severe Thunderstorm Watch	SPC	157 days

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 4.0 hours before the alert went out and 135 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: 231 J/kg
Mixed-layer CIN: -129 J/kg
Mixed-layer LCL: 581 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 114 m²/s²
0-3 km storm-relative helicity: 247 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.

248 
WFUS53 KUNR 100400
TORUNR
SDC055-100500-
/O.NEW.KUNR.TO.W.0008.110510T0400Z-110510T0500Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE RAPID CITY SD
1000 PM MDT MON MAY 9 2011

THE NATIONAL WEATHER SERVICE IN RAPID CITY HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL HAAKON COUNTY IN WEST CENTRAL SOUTH DAKOTA...

* UNTIL 1100 PM MDT

* AT 954 PM MDT...THE PUBLIC REPORTED A TORNADO NEAR OTTUMWA...OR 21
  MILES NORTHEAST OF PHILIP. DOPPLER RADAR SHOWED THIS TORNADO MOVING
  NORTHEAST AT 25 MPH.

  THE TORNADO WAS REPORTED JUST NORTH OF OTTUMWA AROUND 955 PM MDT.

* LOCATIONS IMPACTED INCLUDE...
  AREAS OF EASTERN HAAKON COUNTY SOUTH OF HIGHWAY 34 AND EAST OF     
  OTTUMWA ROAD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. 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 4434 10117 4424 10117 4420 10144 4434 10150
      4452 10116 4451 10115 4435 10115
TIME...MOT...LOC 0358Z 247DEG 20KT 4429 10136

$$

RUDGE

1 follow-up statement

148 
WWUS53 KUNR 100430
SVSUNR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
1030 PM MDT MON MAY 9 2011

SDC055-100440-
/O.CAN.KUNR.TO.W.0008.000000T0000Z-110510T0500Z/
HAAKON SD-
1030 PM MDT MON MAY 9 2011

...THE TORNADO WARNING FOR EAST CENTRAL HAAKON COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 2 AM MDT.

LAT...LON 4434 10117 4424 10117 4420 10144 4434 10150
      4452 10116 4451 10115 4435 10115
TIME...MOT...LOC 0430Z 247DEG 20KT 4436 10113

$$

RUDGE

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Rapid City, SD wrote its last area forecast discussion before this tornado warning went out at May 9, 1:05 PM MDT, 8 hours 55 minutes earlier.

Area forecast discussion, May 9, 1:05 PM MDT, 8 hours 55 minutes before

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
105 PM MDT MON MAY 9 2011

.DISCUSSION...WATER VAPOR SHOWS DEEP UPPER TROF OVER THE GREAT
BASIN WITH INCREASING S/SW FLOW INTO THE NRN PLAINS. JET MAX IS
ROUNDING THE TROF AND NOSING INTO CO AND FAR SRN WY. AT THE
SURFACE...LOW CENTER IS OVER WRN NEB WITH INVERTED TROF EXTENDING
NWD TO BETWEEN KRAP AND KPHP. N/NE BOUNDARY FLOW HELPING LOW STRATUS
TO HANG TOUGH ACROSS MUCH OF THE CWFA...WITH THE EXCEPTION OF THE
MOSTLY CLEAR SKIES FROM OVER THE BLKHLS THROUGH SERN WY.

LATER THIS AFTERNOON AND TONIGHT...JET STREAK WILL NOSE INTO OUR
CWFA CREATING WIDESPREAD SYNOPTIC LIFT. SURFACE BASED CAPE WILL BE
HARD TO COME BY IN AREAS THAT ARE COVERED IN LOW STRATUS...BUT WITH
MUCAPE IN THE 1000J/KG (FAR WRN SD) TO 3000 J/KG (SCNTRL SD)
RANGE...ELEVATED STORMS WILL BE LIKELY. SHEAR IS NOT OVERLY
IMPRESSIVE...BUT SHOULD INCREASE AS JET STREAK PASSES OVERHEAD.
AREAS THAT HAVE NOT SEEN THE STRATUS ARE MORE LIKELY TO SEE SFC
BASED CONVECTION. MAIN THREAT IS LIKELY TO BE LARGE HAIL...BUT
SHOULD ANY STORMS BECOME SURFACE BASED NEAR THE INVERTED TROF OVER
SWRN/SCNTRL SD THERE IS SUFFICIENT LO LEVEL SHEAR FOR A TORNADIC
THREAT. SEVERE THREAT SHOULD WAIN AFTER MIDNIGHT AS BEST
CONVECTIVE PARAMETERS SHIFT TO OUR EAST.

TUESDAY...UPPER LOW WILL CUT OFF OVER SERN MT AND MOVE NEWD ACROSS
WRN ND...WITH DRY SLOT OVER CNTRL SD LIMITING PCPN POTENTIAL IN OUR
ERN ZONES. WELL DEFINED TROWAL WILL WRAP AROUND UPPER LOW WITH
HEAVIEST RAINS LIKELY WEST AND NORTHWEST OF THE BLKHLS. THUS...WILL
KEEP FLOOD WATCH IN PLACE. WINDY CONDITIONS LIKELY TO DEVELOP ACROSS
MUCH OF THE AREA WITH STRONG 850-700MB GRADIENT IN PLACE. PCPN WILL
DECREASE LATE TUESDAY NIGHT AS UPPER LOW SHIFTS IN SCNTRL CANADA.

WEDNESDAY...SOUTHERN STREAM UPPER LOW WILL MOVE THROUGH THE CNTRL
PLAINS...WITH JUST ENOUGH ENERGY FOR A FEW -SHRA ACRS OUR
CWFA...ESPECIALLY SCNTRL SD. TEMPS WILL REMAIN ON THE COOL SIDE WITH
BREEZY NW WINDS.

EXTENDED...LARGE UPPER TROF SHIFTS EAST ON THURSDAY WITH SOME
LINGERING SHOWERS POSSIBLE FROM THE BLACK HILLS EAST. BLOCKING
PATTERN SETS UP FOR THE REMAINDER OF THE WEEK INTO EARLY NEXT
WEEK...BRINGING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES.

&&

.AVIATION...LOW STRATUS WILL PERSIST OVER MOST OF NORTHEASTERN WY
AND FAR WESTERN SD THROUGH THE AFTERNOON AND OVERNIGHT...BRINGING
AREAS OF IFR/MVFR CIGS. SHOWERS AND THUNDERSTORMS WILL DEVELOP
ACROSS THE AREA LATE THIS AFTERNOON INTO TONIGHT...WITH LCL IFR VIS
IN HEAVIER PRECIP. SOME STORMS MAY BECOME SEVERE THIS AFT AND EVE.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR BUTTE-HARDING-
     NORTHERN BLACK HILLS-NORTHERN FOOT HILLS-PERKINS.

WY...FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR NORTHEASTERN CROOK-
     WESTERN CROOK-WYOMING BLACK HILLS.

&&

JOHNSON/RUDGE

Hazardous weather outlook, May 9, 4:20 AM MDT, 17 hours 40 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
420 AM MDT MON MAY 9 2011

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-101300-
BENNETT-BUTTE-CENTRAL BLACK HILLS-CUSTER CO PLAINS-FALL RIVER-HAAKON-
HARDING-HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHEASTERN CROOK-
NORTHERN BLACK HILLS-NORTHERN CAMPBELL-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-
SHANNON-SOUTHERN BLACK HILLS-SOUTHERN CAMPBELL-SOUTHERN FOOT HILLS-
SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-
WESTERN CROOK-WESTON-WYOMING BLACK HILLS-ZIEBACH-
420 AM MDT (520 AM CDT) MON MAY 9 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT

A STRONG UPPER LEVEL STORM SYSTEM WILL AFFECT THE AREA THIS
AFTERNOON INTO TONIGHT...RESULTING IN NUMEROUS SHOWERS AND
THUNDERSTORMS. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER
WESTERN SOUTH DAKOTA AND PORTIONS OF NORTHEAST WYOMING THIS AFTERNOON
AND EVENING...WITH LARGE HAIL. LOCALLY HEAVY RAIN IS ALSO POSSIBLE
ACROSS PORTIONS OF NORTHEAST WYOMING AND NORTHWEST SOUTH DAKOTA.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE STRONG UPPER LEVEL STORM SYSTEM WILL MOVE INTO FAR WESTERN NORTH
DAKOTA ON TUESDAY. THIS WILL BRING LOCALLY HEAVY RAIN TO PORTIONS OF
NORTHEAST WYOMING AND FAR NORTHWEST SOUTH DAKOTA. A FEW
THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS OF WESTERN SOUTH
DAKOTA...SEVERE THUNDERSTORMS ARE NOT EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY ACROSS WESTERN SOUTH DAKOTA.

In the hours before

Local storm report, May 9, 9:35 PM MDT, 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
935 PM MDT MON MAY 09 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0932 PM     FLASH FLOOD      DOWNTOWN NEWCASTLE      43.85N 104.20W
05/09/2011                   WESTON             WY   LAW ENFORCEMENT

            WIDESPREAD STREET FLOODING ACROSS NEWCASTLE. DEBRIS
            EVERYWHERE. CULVERTS ARE BLOCKED. SEWERS ARE BACKED UP.
            FOUR HOUSES HAVE BASEMENTS FLOODED. CAR REPORTEDLY
            FLOATING DOWN ROAD. LIMITED TRAVEL ADVISED.

&&

CALDERON

Local storm report, May 9, 9:43 PM MDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
943 PM MDT MON MAY 09 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0940 PM     TSTM WND GST     N SHARPS CORNER         43.39N 102.40W
05/09/2011  E60 MPH          SHANNON            SD   TRAINED SPOTTER

&&

CALDERON

Local storm report, May 9, 9:44 PM MDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
944 PM MDT MON MAY 09 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0910 PM     TORNADO          8 N PHILIP              44.16N 101.67W
05/09/2011                   HAAKON             SD   PUBLIC

&&

CALDERON

Local storm report, May 9, 9:47 PM MDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
947 PM MDT MON MAY 09 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0935 PM     HAIL             18 E FAIRBURN           43.69N 102.85W
05/09/2011  E1.00 INCH       CUSTER             SD   TRAINED SPOTTER

&&

CALDERON

Local storm report, May 9, 9:48 PM MDT, 12 minutes before

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE RAPID CITY SD
948 PM MDT MON MAY 09 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0532 PM     HAIL             FOUR CORNERS            44.08N 104.13W
05/09/2011  E0.88 INCH       WESTON             WY   PUBLIC

0544 PM     HAIL             DOWNTOWN NEWCASTLE      43.85N 104.20W
05/09/2011  E0.88 INCH       WESTON             WY   LAW ENFORCEMENT

0545 PM     HAIL             DOWNTOWN NEWCASTLE      43.85N 104.20W
05/09/2011  E1.50 INCH       WESTON             WY   PUBLIC

0615 PM     FLASH FLOOD      DOWNTOWN NEWCASTLE      43.85N 104.20W
05/09/2011                   WESTON             WY   LAW ENFORCEMENT

            WATER WAS REPORTED FLOWING OVER THE HIGHWAY 16 BYPASS AND
            AT THE INTERSECTION OF SPOKANE AVE AND SPRINGFIELD AVE.

0637 PM     FLASH FLOOD      DOWNTOWN NEWCASTLE      43.85N 104.20W
05/09/2011                   WESTON             WY   LAW ENFORCEMENT

            SEVERAL STREETS IN NEWCASTLE ARE FLOODING.

0735 PM     HAIL             3 S OPAL                44.85N 102.61W
05/09/2011  E1.25 INCH       MEADE              SD   PUBLIC

0735 PM     TSTM WND GST     3 S OPAL                44.85N 102.61W
05/09/2011  E60.00 MPH       MEADE              SD   PUBLIC

0740 PM     HAIL             OPAL                    44.89N 102.61W
05/09/2011  E1.50 INCH       MEADE              SD   PUBLIC

0758 PM     HAIL             QUINN                   43.99N 102.13W
05/09/2011  M1.75 INCH       PENNINGTON         SD   STORM CHASER

0810 PM     HAIL             3 NE QUINN              44.02N 102.09W
05/09/2011  E2.00 INCH       PENNINGTON         SD   PUBLIC

            HAIL LASTED 25 MINUTES.

0849 PM     HAIL             1 S OGLALA              43.17N 102.73W
05/09/2011  E1.00 INCH       SHANNON            SD   TRAINED SPOTTER

0910 PM     TORNADO          8 N PHILIP              44.16N 101.67W
05/09/2011                   HAAKON             SD   PUBLIC

0915 PM     HAIL             6 NNW PINE RIDGE        43.11N 102.60W
05/09/2011  E1.00 INCH       SHANNON            SD   PUBLIC

0932 PM     FLASH FLOOD      DOWNTOWN NEWCASTLE      43.85N 104.20W
05/09/2011                   WESTON             WY   LAW ENFORCEMENT

            WIDESPREAD STREET FLOODING ACROSS NEWCASTLE. DEBRIS
            EVERYWHERE. CULVERTS ARE BLOCKED. SEWERS ARE BACKED UP.
            FOUR HOUSES HAVE BASEMENTS FLOODED. CAR REPORTEDLY
            FLOATING DOWN ROAD. LIMITED TRAVEL ADVISED.

0935 PM     HAIL             18 E FAIRBURN           43.69N 102.85W
05/09/2011  E1.00 INCH       CUSTER             SD   TRAINED SPOTTER

0940 PM     TSTM WND GST     N SHARPS CORNER         43.39N 102.40W
05/09/2011  E60.00 MPH       SHANNON            SD   TRAINED SPOTTER

&&

CALDERON

Local storm report, May 9, 10:00 PM MDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1000 PM MDT MON MAY 09 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0955 PM     TSTM WND GST     8 WNW USTA              45.25N 102.31W
05/09/2011  E70 MPH          PERKINS            SD   TRAINED SPOTTER

&&

CALDERON

The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 9, 6:49 PM MDT	Flash Flood Warning	UNR	Custer, Fall River	4 hr
May 9, 6:58 PM MDT	Severe Thunderstorm Warning	UNR	Fall River	62 min
May 9, 7:21 PM MDT	Severe Thunderstorm Warning	UNR	Meade	54 min
May 9, 7:34 PM MDT	Severe Thunderstorm Warning	UNR	Meade, Perkins	56 min
May 9, 7:51 PM MDT	Severe Thunderstorm Warning	UNR	Haakon, Pennington	42 min
May 9, 7:56 PM MDT	Severe Thunderstorm Warning	UNR	Meade	64 min
May 9, 8:04 PM MDT	Tornado Warning	UNR	Fall River	56 min
May 9, 8:10 PM MDT	Tornado Warning	UNR	Haakon	65 min
May 9, 8:13 PM MDT	Severe Thunderstorm Warning	UNR	Haakon, Meade, Pennington, Ziebach	62 min
May 9, 8:19 PM MDT	Flash Flood Warning	UNR	Meade, Perkins, Ziebach	6 hr
May 9, 8:24 PM MDT	Severe Thunderstorm Warning	UNR	Meade, Perkins	66 min
May 9, 8:35 PM MDT	Severe Thunderstorm Warning	UNR	Meade	46 min
May 9, 8:57 PM MDT	Severe Thunderstorm Warning	UNR	Custer, Pennington	78 min
May 9, 9:01 PM MDT	Tornado Warning	UNR		59 min
May 9, 9:06 PM MDT	Tornado Warning	UNR	Haakon	54 min
May 9, 9:13 PM MDT	Severe Thunderstorm Warning	UNR	Meade, Ziebach	62 min
May 9, 9:36 PM MDT	Severe Thunderstorm Warning	UNR	Bennett, Jackson	69 min
May 9, 9:44 PM MDT	Severe Thunderstorm Warning	UNR	Perkins	61 min
May 9, 9:48 PM MDT	Tornado Warning	UNR	Bennett	42 min
May 9, 10:10 PM MDT	Severe Thunderstorm Warning	UNR	Ziebach	65 min
May 9, 10:19 PM MDT	Areal Flood Warning	UNR	Custer, Fall River	16 hr
May 9, 10:35 PM MDT	Severe Thunderstorm Warning	UNR	Jackson	55 min
May 9, 10:41 PM MDT	Severe Thunderstorm Warning	UNR	Butte, Harding	38 min
May 9, 11:03 PM MDT	Severe Thunderstorm Warning	UNR	Haakon	42 min
May 9, 11:09 PM MDT	Severe Thunderstorm Warning	UNR	Meade, Pennington	51 min
May 9, 11:16 PM MDT	Tornado Warning	UNR	Haakon, Pennington	24 min
May 9, 11:45 PM MDT	Severe Thunderstorm Warning	UNR	Haakon, Meade, Perkins, Ziebach	60 min
May 9, 11:48 PM MDT	Flash Flood Warning	UNR	Perkins, Ziebach	3 hr
May 10, 2:22 AM MDT	Areal Flood Warning	UNR	Meade, Perkins, Ziebach	12 hr

Nearby

Tornado Warnings in South Dakota, 2011 Every tornado warning in 2011 Tornadoes 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.