Alert archive / South Dakota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 24, NWS Rapid City, SD

May 18, 2012Jackson County, South Dakota

NWS Rapid City, SD issued this severe thunderstorm warning at May 18, 2012, 5:34 PM MDT for Jackson County, South Dakota. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 18, 2012, 5:34 PM MDT (23:34 UTC)
Expired
May 18, 2012, 6:30 PM MDT
In force
56 min
Issued by
NWS Rapid City, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Jackson County, SD

The radar

The Rapid City radar (KUDX), 108 km from the middle of the area, began a volume at 23:34 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

Rapid City, SD (KUNR), launched 12:00Z, 11.6 hours before the alert went out and 109 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, Rapid City, SD at 12:00Z on 2012-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2012-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 square meters per square second.1939Sfc1 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
2604 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at May 18, 2:37 PM MDT, 2 hours 57 minutes earlier.

Area forecast discussion, May 18, 2:37 PM MDT, 2 hours 57 minutes before
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
237 PM MDT FRI MAY 18 2012

.DISCUSSION...
APPROACHING SHORT WAVE TROF OVER NRNG NV THIS MORNING HAS VERY
STRONG DIFLUENCE AHEAD OF IT FROM THE NE PANHANDLE TO NW CO. NAM AND
GFS FCST THE DIFLUENCE AREA TO MOVE OVER SW AND THEN S CTNRL SD
THIS AFTN AND THIS EVENING. 700 MB Q VECTOR CONVERGENCE IS ALSO
FCST TO CROSS THE AREA TONIGHT...PERSISTING INTO SATURDAY. AT THE
SFC A BOUNDARY EXTENDS ACROSS WRN SD THIS AFTN WITH MODEST TEMP
GRADIENT. THIS BOUNDARY WILL BE REINFORCED AS A SURGE OF COLDER AIR
DRIVES SOUTH TONIGHT OVER WRN SD ACCOMPANIED BY VERY STRONG SFC
WINDS...ESPECIALLY JUST EAST OF THE BLACK HILLS.

TSTM ACTIVITY IS DVLPG THIS AFTN IN THE DIFLUENT AREA OVER WY AND
OVER THE BLACK HILLS. THE AIR MASS IS RELATIVELY DRY...SO STORMS
WILL BE HIGH BASED WITH POTENTIAL FOR STRONG SFC WIND GUSTS AND
SOME HAIL...ESPECIALLY NEAR AND JUST NORTH OF THE SFC BOUNDARY
WHERE DEEP LAYER SHEAR IS GREATER AND CAPE IS SUFFICIENT. THIS
ACTIVITY SHOULD PERSIST INTO THE EVENING HOURS WITH SOME SVR
THREAT UNTIL LATE EVG. WITH FORCING FOR ASCENT CONTINUING OVER THE
AREA...WIDESPREAD SHOWER AND TSTM ACTIVITY WILL CONTINUE INTO THE
OVERNIGHT HOURS...ENDING FROM NW TO SE ON SATURDAY MORNING.

SURGE OF COLDER AIR WITH STRONG PRESSURE RISES WILL PRODUCE VERY
STRONG AND GUSTY WINDS OVER NIGHT WITH STRONGEST WINDS IN TYPICAL
AREA OF CONFLUENCE JUST EAST OF THE BLACK HILLS WITH NORTHERLY
FLOW. HAVE ISSUED A WIND ADVISORY FOR MUCH OF THE CWA EAST OF THE
HILLS AND A HIGH WIND WARNING FOR THE MOST CRITICAL AREA INCLUDING
RAPID CITY. WINDS WILL REMAIN STRONG INTO THE MORNING HOURS
SATURDAY...THEN DIMINISH.

EXTENDED...AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION EARLY
NEXT WEEK...BRINGING DRY CONDITIONS AND A WARMING TREND FROM SUNDAY
INTO TUESDAY. MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A SLOW MOVING
UPPER TROUGH PUSHING INTO THE REGION LATE TUESDAY...BUT PLACEMENT OF
THE BASE OF THE TROF VARIES FROM SOUTHERN CANADA TO SOUTH DAKOTA.
WITH THE POOR CONSISTENCY OF THE MODELS CONTINUING...WILL GENERALLY
KEEP BROAD BRUSHED SLIGHT CHANCE TO CHANCE POPS ACROSS THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. TEMPERATURES WILL GENERALLY BE
COOLER MIDWEEK...BUT EXTENT OF COOLING WILL DEPEND ON THE TRACK OF
THE SYSTEM.

&&

.AVIATION...18Z TAF UPDATE
CONDITIONS WILL DETERIORATE TO MVFR FROM WEST TO EAST LATE THIS
AFTERNOON THROUGH THIS EVENING. SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS NORTHEAST WYOMING AS A VIGOROUS WEATHER SYSTEM
APPROACHES. THIS ACTIVITY WILL EXPAND EAST ACROSS THE AREA LATE THIS
AFTERNOON AND EARLY EVENING...AND CONTINUE THROUGH TONIGHT WITH
LOCAL IFR CONDITIONS EXPECTED NEAR STRONGER STORMS. HAIL AND STRONG
WINDS WILL BE POSSIBLE WITH THESE STORMS THIS EVENING. STRONG AND
GUSTY NORTH TO NORTHWEST WINDS WILL DEVELOP ACROSS MUCH OF THE
WESTERN SD PLAINS DURING THE EVENING AND OVERNIGHT HOURS BEHIND THE
FRONTAL PASSAGE. THE STRONGEST WINDS LOOK TO BE ACROSS THE WEST
CENTRAL SD PLAINS...INCLUDING KRAP...WHERE GUSTS OVER 50 MPH ARE
LIKELY LATE TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 8 PM THIS EVENING TO 10 AM MDT SATURDAY FOR
     HAAKON-HARDING-HERMOSA FOOT HILLS-JACKSON-NORTHERN FOOT
     HILLS-PERKINS-SHANNON-ZIEBACH.

     HIGH WIND WARNING FROM 8 PM THIS EVENING TO 10 AM MDT SATURDAY
     FOR BUTTE-CUSTER CO PLAINS-NORTHERN MEADE CO PLAINS-
     PENNINGTON CO PLAINS-RAPID CITY-SOUTHERN MEADE CO PLAINS-
     STURGIS/PIEDMONT FOOT HILLS.

WY...NONE.
&&

SHORT TERM...BARBER
LONG TERM....15
AVIATION...15
Hazardous weather outlook, May 18, 6:36 AM MDT, 10 hours 58 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
636 AM MDT FRI MAY 18 2012

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-181300-
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-
636 AM MDT (736 AM CDT) FRI MAY 18 2012

...HIGH WIND WATCH TONIGHT FOR THE LEE SIDE OF THE BLACK HILLS...

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

.DAY ONE...TODAY AND TONIGHT

A STRONG COLD FRONT WILL DEVELOP TODAY OVER MONTANA AND MOVE ACROSS
THE AREA LATE THIS AFTERNOON AND EVENING. THUNDERSTORMS ARE
EXPECTED ALONG AND BEHIND THE FRONT. ISOLATED SEVERE THUNDERSTORMS
ARE POSSIBLE...ESPECIALLY NORTH AND EAST OF THE BLACK HILLS. LARGE
HAIL AND DAMAGING WINDS WILL BE THE MAIN THREAT.

BEHIND THE FRONT THIS EVENING...STRONG GUSTY NORTHWEST WINDS WILL
OCCUR. GUSTS AROUND 60 MPH ARE POSSIBLE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

ISOLATED THUNDERSTORMS MAY OCCUR SATURDAY ON THE SOUTH DAKOTA
PLAINS...BUT SEVERE STORMS ARE NOT EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

In the hours before

Special weather statement, May 18, 3:45 PM MDT, 1 hour 49 minutes before
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Special weather statement, May 18, 4:12 PM MDT, 1 hour 22 minutes before
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Special weather statement, May 18, 4:39 PM MDT, 55 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
439 PM MDT FRI MAY 18 2012

SDZ041-182315-
FALL RIVER SD-
439 PM MDT FRI MAY 18 2012

AT 433 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR OELRICHS...OR 24 MILES SOUTHEAST OF DOWNTOWN
HOT SPRINGS...MOVING NORTHEAST AT 25 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE
POSSIBLE WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...
MAINLY RURAL AREAS OF EASTERN FALL RIVER COUNTY SOUTHEAST OF
SMITHWICK.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

&&

LAT...LON 4307 10312 4317 10331 4339 10316 4332 10300
      4320 10300
TIME...MOT...LOC 2238Z 209DEG 22KT 4319 10316

JC
Special weather statement, May 18, 4:45 PM MDT, 49 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
445 PM MDT FRI MAY 18 2012

SDZ031-042-043-182315-
JACKSON SD-PENNINGTON CO PLAINS SD-SHANNON SD-
445 PM MDT FRI MAY 18 2012

AT 442 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES SOUTHEAST OF
SCENIC TO POTATO CREEK...AND MOVING NORTH AT 30 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 50 MPH ARE
POSSIBLE WITH THESE STORMS...ALONG WITH FREQUENT DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...
  POTATO CREEK...
  PINNACLES RANGER STATION...
  INTERIOR...
  CEDAR PASS...

THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 4399 10242 4382 10201 4355 10176 4339 10205
      4355 10228 4368 10258
TIME...MOT...LOC 2244Z 199DEG 24KT 4375 10244 4363 10214
          4348 10199

JC
Special weather statement, May 18, 5:14 PM MDT, 20 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
514 PM MDT FRI MAY 18 2012

SDZ042-182345-
SHANNON SD-
514 PM MDT FRI MAY 18 2012

AT 511 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 7 MILES SOUTHWEST OF PINE RIDGE...MOVING NORTH AT
25 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE
POSSIBLE WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...
  PINE RIDGE...
  OGLALA...

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

&&

LAT...LON 4326 10280 4319 10234 4299 10251 4299 10280
      4300 10281
TIME...MOT...LOC 2314Z 195DEG 23KT 4300 10267

JC
Special weather statement, May 18, 5:18 PM MDT, 16 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
518 PM MDT FRI MAY 18 2012

SDZ043-182345-
JACKSON SD-
518 PM MDT FRI MAY 18 2012

AT 516 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR POTATO CREEK...OR 29 MILES SOUTHWEST OF
KADOKA...MOVING NORTHEAST AT 15 MPH.

HAIL UP TO THE SIZE OF NICKELS IS POSSIBLE WITH THIS STORM...ALONG
WITH FREQUENT DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...
  INTERIOR...

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

&&

LAT...LON 4356 10212 4375 10201 4367 10175 4349 10199
TIME...MOT...LOC 2318Z 204DEG 14KT 4360 10199

JC

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 7:15 PM MDTSpecial Weather StatementUNRMeade45 min
May 17, 7:25 PM MDTSpecial Weather StatementUNR50 min
May 18, 3:38 AM MDTHigh Wind WatchUNRButte, Custer, Lawrence, Meade, Pennington11 hr
May 18, 2:34 PM MDTSpecial Weather StatementUNRLawrence41 min
May 18, 2:45 PM MDTHigh Wind WarningUNRButte, Custer, Meade, Pennington12 hr
May 18, 2:45 PM MDTWind AdvisoryUNRButte, Custer, Haakon, Harding, Jackson, Lawrence and 5 more20 hr
May 18, 2:46 PM MDTSevere Thunderstorm WarningUNRLawrence, Meade46 min
May 18, 3:27 PM MDTSpecial Weather StatementUNRCuster48 min
May 18, 3:45 PM MDTSpecial Weather StatementUNRFall River30 min
May 18, 4:12 PM MDTSpecial Weather StatementUNROglala Lakota33 min
May 18, 4:39 PM MDTSpecial Weather StatementUNRFall River36 min
May 18, 4:45 PM MDTSpecial Weather StatementUNRJackson30 min
May 18, 5:14 PM MDTSpecial Weather StatementUNROglala Lakota31 min
May 18, 5:18 PM MDTSpecial Weather StatementUNRJackson27 min
May 18, 5:59 PM MDTSevere Thunderstorm WarningUNRJackson61 min
May 17, 6:23 PM MDTSpecial Weather StatementUNRCampbell37 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2012Every severe thunderstorm warning 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.