Alert archive / South Dakota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 165, NWS Rapid City, SD

July 19, 2012Todd County, Tripp County, South Dakota

NWS Rapid City, SD issued this severe thunderstorm warning at Jul 19, 2012, 6:58 PM CDT for Todd County, Tripp County, South Dakota. It was in force for 92 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
Jul 19, 2012, 6:58 PM CDT (23:58 UTC)
Expired
Jul 19, 2012, 8:30 PM CDT
In force
92 min
Issued by
NWS Rapid City, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
75.0 mph

Counties Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 148 km from the middle of the area, began a volume at 00:00 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, 12.0 hours before the alert went out and 226 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 2012-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 97 joules per kilogram.LCLLFCEL10008507005003002001001 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 2012-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -43 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
97 J/kg
Mixed-layer CIN
-477 J/kg
Mixed-layer LCL
3320 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-43 m²/s²
0-3 km storm-relative helicity
23 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 Jul 19, 6:26 PM CDT, 32 minutes earlier.

Area forecast discussion, Jul 19, 6:26 PM CDT, 32 minutes before
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
526 PM MDT THU JUL 19 2012

.AVIATION...00Z TAF
ISOLATED THUNDERSTORMS...MAINLY ACROSS CENTRAL SD...WILL CONTINUE
INTO THE EVENING. SOME OF THESE STORMS COULD PRODUCE HAIL AND
STRONG WIND GUSTS. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS OVER
NORTHEASTERN WY INTO WESTERN AND CENTRAL SD FRIDAY AFTERNOON.
OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.

&&

.PREV DISCUSSION... /ISSUED 227 PM MDT THU JUL 19 2012/

DISCUSSION...20Z SURFACE ANALYSIS HAD LOW JUST NORTH OF OWANKA
WITH BOUNDARY TO KCUT BACK INTO THE NORTHERN BLACK HILLS. ANOTHER
BOUNDARY LOCATED FROM RED SCAFFOLD TO KPHP TO KIEN. EACH OF THESE
BOUNDARIES...CLEARLY DEPICTED ON KUDX WSR-88D...INITIATING WEAK
CONVECTION UNDER A 500-1000J/KG MLCAPE REGIME WITH 25-50J/KG
MLCIN. SHEAR IS MARGINAL...BUT GIVEN INVERTED-V SOUNDINGS ANY
STORM COULD PRODUCE STRONG ERRATIC WIND GUSTS. THERE IS A HINT OF
UPPER SUPPORT ON WATER VAPOUR OVER NORTHEAST WY. MOST ACTIVITY
SHOULD DISSIPATE THIS EVENING. OVERNIGHT...LOW LEVEL JET CRANKS UP
FROM CENTRAL NE INTO CENTRAL SD WITH BEST CONVERGENCE/THETA-E
ADVECTION NORTHEAST OF THE CWA SO WILL LEAVE ELEVATED -TSRA OUT OF
FORECAST. TEMPERATURES WILL BE QUITE WARM TONIGHT GIVEN BOUNDARY
LAYER PROFILES.

FRIDAY/SATURDAY...UPPER LEVEL/THERMAL RIDGE REMAINS OVER THE CWA.
GUIDANCE NOW SHOWING WEAK COOL FRONT...CURRENTLY IN
MT/ND...SLIPPING SLOWLY SOUTH FRIDAY INTO CWA...AND THUS HAVE
LOWERED TEMPERATURES SOME IN THE NORTH AND WEST. FRONT WILL LIKELY
BE FOCUS FOR AFTERNOON/NIGHTTIME TSRA ACTIVITY. FINAL POSITIONING
OF FRONT AND ANY RIDGE RIDING SHORTWAVES TENTATIVE AT BEST...AND
THUS HAVE TENDED TO BROAD BRUSH POPS GIVEN UNCERTAINTY. HEAT
INDICES WILL MEET CRITERIA OVER MOST OF THE SD PLAINS FRIDAY AND
OVER EASTERN PORTIONS OF THE CWA SATURDAY...SO HAVE EXTENDED
ADVISORY FOR CENTRAL SD INTO SATURDAY. FORECAST SOUNDING INDICATED
SEVERE POSSIBLE EACH DAY...WITH THE BEST CHANCE FRIDAY AFTERNOON
OVER THE NORTHWEST 1/2 OF THE CWA GIVEN SHEAR PROFILE/MLCAPE.

EXTENDED...STRONG UPPER LEVEL RIDGING WILL DOMINATE OVER THE CENTRAL
PLAINS THROUGH THE LONG TERM. WEST TO SOUTHWEST FLOW AROUND THE
RIDGE WILL PERSIST ACROSS THE CWA. THIS WILL BRING DAILY CHANCES OF
THUNDERSTORMS ACROSS VARYING PARTS OF THE CWA AS DISTURBANCES CROSS
THE AREA. ABOVE AVERAGE TEMPERATURES WILL ALSO CONTINUE WITH HIGHS
IN THE 90S TO LOWER 100S. MODELS ARE INDICATING A COOL FRONT MAY
CROSS THE AREA LATE WEDNESDAY WHICH MAY BRING MORE SEASONABLE
TEMPERATURES AND DRIER AIR TO THE AREA LATE IN THE WEEK.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...HEAT ADVISORY UNTIL MIDNIGHT MDT /1 AM CDT/ SATURDAY NIGHT FOR
     BENNETT-HAAKON-JACKSON-MELLETTE-TODD-TRIPP-ZIEBACH.

     HEAT ADVISORY UNTIL MIDNIGHT MDT FRIDAY NIGHT FOR BUTTE-CUSTER
     CO PLAINS-FALL RIVER-HARDING-HERMOSA FOOT HILLS-NORTHERN
     FOOT HILLS-NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-
     PERKINS-RAPID CITY-SHANNON-SOUTHERN FOOT HILLS-SOUTHERN
     MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS.

WY...NONE.
&&
Hazardous weather outlook, Jul 19, 3:46 PM CDT, 3 hours 12 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
246 PM MDT THU JUL 19 2012

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-201300-
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-
246 PM MDT (346 PM CDT) THU JUL 19 2012

...HEAT ADVISORY THROUGH MIDNIGHT FRIDAY NIGHT FOR WESTERN SOUTH
DAKOTA PLAINS...
...HEAT ADVISORY THROUGH MIDNIGHT SATURDAY NIGHT FOR CENTRAL SOUTH
DAKOTA...

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

.DAY ONE...TODAY AND TONIGHT

A FEW THUNDERSTORMS WILL OCCUR THROUGH THIS EVENING ON THE SOUTH
DAKOTA PLAINS. ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE WITH
DAMAGING WINDS THE MAIN THREAT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A STRONG UPPER LEVEL RIDGE WILL BRING HOT WEATHER THROUGH EARLY
NEXT WEEK. HEAT INDICES WILL PEAK FROM 100 TO 110 DEGREES FRIDAY ON
THE SOUTH DAKOTA PLAINS...AND THEN 100 TO 105 DEGREES OVER CENTRAL
SOUTH DAKOTA SATURDAY. HEAT EXHAUSTION AND HEAT STROKE ARE POSSIBLE
DURING THESE CONDITIONS. EXTREME HEAT CAN ALSO BE DANGEROUS TO PETS
AND LIVESTOCK.

THUNDERSTORMS ARE POSSIBLE THROUGH EARLY NEXT WEEK. SEVERE
THUNDERSTORMS ARE POSSIBLE OVER NORTHEAST WYOMING AND WESTERN
SOUTH DAKOTA FRIDAY AND SATURDAY. THE MAIN THREAT FROM THESE
STORMS WILL BE DAMAGING WINDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.

In the hours before

Special weather statement, Jul 19, 4:36 PM CDT, 2 hours 22 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
336 PM MDT THU JUL 19 2012

SDZ046-192215-
MELLETTE SD-
436 PM CDT THU JUL 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL MELLETTE COUNTY UNTIL 515
PM CDT...

AT 434 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR CEDAR BUTTE...OR 13 MILES WEST OF WHITE
RIVER...MOVING EAST AT 20 MPH.

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

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...
  WHITE RIVER...
  WOOD...

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

&&

LAT...LON 4359 10113 4374 10076 4372 10072 4376 10065
      4375 10063 4377 10060 4374 10052 4343 10044
      4343 10109
TIME...MOT...LOC 2136Z 255DEG 19KT 4354 10100

CALDERON
Special weather statement, Jul 19, 4:57 PM CDT, 2 hours 1 minute before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
357 PM MDT THU JUL 19 2012

SDZ043-046-192245-
JACKSON SD-MELLETTE SD-
457 PM CDT THU JUL 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN MELLETTE AND SOUTHEASTERN
JACKSON COUNTIES UNTIL 545 PM CDT/445 PM MDT/...

AT 355 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 5 MILES NORTH OF NORRIS...OR 24 MILES SOUTHEAST
OF KADOKA...MOVING EAST AT 10 MPH.

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

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...
  NORRIS...
  CEDAR BUTTE...

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

&&

LAT...LON 4367 10089 4342 10088 4345 10133 4363 10134
TIME...MOT...LOC 2157Z 268DEG 9KT 4354 10123

CALDERON
Special weather statement, Jul 19, 5:19 PM CDT, 1 hour 39 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
419 PM MDT THU JUL 19 2012

SDZ043-044-046-047-049-192315-
BENNETT SD-JACKSON SD-MELLETTE SD-TODD SD-TRIPP SD-
519 PM CDT THU JUL 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR MELLETTE...EASTERN BENNETT...
SOUTHEASTERN JACKSON...TODD AND NORTHWESTERN TRIPP COUNTIES UNTIL 615
PM CDT/515 PM MDT/...

AT 518 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES NORTHEAST OF
WHITE RIVER TO 9 MILES EAST OF PARMELEE TO 9 MILES SOUTH OF
HARRINGTON...AND MOVING NORTHEAST AT 25 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THESE STORMS...ALONG WITH FREQUENT DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...
  MISSION...
  SPRING CREEK...
  SAINT FRANCIS...
  LAKEVIEW...
  ROSEBUD...
  WOOD...
  MOSHER...
  OKREEK...
  HIDDEN TIMBER...
  CARTER...
  LITTLEBURG...
  WITTEN...

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

&&

LAT...LON 4343 10134 4383 10097 4384 10092 4372 10072
      4377 10058 4374 10051 4374 10036 4371 10028
      4370 9988 4299 10035 4299 10152 4300 10153
TIME...MOT...LOC 2220Z 229DEG 23KT 4364 10068 4338 10083
          4305 10119

CALDERON
Special weather statement, Jul 19, 6:15 PM CDT, 43 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
615 PM CDT THU JUL 19 2012

SDZ046-047-049-200000-
MELLETTE SD-TODD SD-TRIPP SD-
615 PM CDT THU JUL 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN MELLETTE...TODD AND TRIPP
COUNTIES UNTIL 700 PM CDT...

AT 610 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 16 MILES NORTH OF
MOSHER TO 6 MILES NORTHEAST OF CROOKSTON...AND MOVING EAST AT 30 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...
  WINNER...
  OKREEK...
  MOSHER...
  HIDDEN TIMBER...
  LITTLEBURG...
  CARTER...
  WITTEN...
  IDEAL...
  KEYAPAHA...
  CLEARFIELD...
  HAMILL...
  MILLBORO...
  COLOME...
  WEWELA...

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

&&

LAT...LON 4299 9955 4299 10114 4373 10078 4372 10072
      4377 10058 4373 10046 4374 10036 4371 10028
      4371 10001 4368 9988 4371 9977 4375 9976
      4376 9963 4351 9961 4350 9952
TIME...MOT...LOC 2315Z 276DEG 28KT 4369 10022 4300 10063

CALDERON
Local storm report, Jul 19, 6:31 PM CDT, 27 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 3:27 PM CDTSpecial Weather StatementUNRJackson48 min
Jul 19, 4:16 PM CDTSpecial Weather StatementUNRJackson59 min
Jul 19, 4:36 PM CDTSpecial Weather StatementUNRMellette39 min
Jul 19, 4:57 PM CDTSpecial Weather StatementUNRMellette48 min
Jul 19, 5:19 PM CDTSpecial Weather StatementUNRMellette, Todd56 min
Jul 19, 6:15 PM CDTSpecial Weather StatementUNRMellette, Todd, Tripp45 min
Jul 19, 6:20 PM CDTSevere Thunderstorm WarningUNRMellette, Todd, Tripp55 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.