Special Weather Statement, NWS Rapid City, SD

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
517 PM MDT Wed Jun 23 2021

.DISCUSSION...(This Evening Through Wednesday)
Issued at 226 PM MDT Wed Jun 23 2021

Current models show the upper ridge stretching from NM up through
ID/MT today. By Thursday, upper flow over the region starts to
become more zonal as a strong upper low over the Pacific coast
helps to flattens the ridge. Several shortwaves are forecast to
move up from the SW through the rest of this week. The first being
today, as a frontal boundary makes its way over the region later
this evening. CAMs are showing shower and thunderstorm development
later this afternoon and evening over Wyoming, pushing through
the forecast area. Weak CAPE values in the 100-300 J/Kg range and
marginal shear should limit severe potential, however for storms
that do develop, winds will be the greater threat. Strong low
level lapse rates and DCAPE values in the 1000-2000 J/Kg bring a
decent chance for severe wind potential.

Temps trend toward near normal following frontal passage this
evening, with highs Thursday in the 80s, and Friday in the low to
mid 70s as the upper trough digs into the rockies. Later Thursday
looks to be the next chance for precipitation over the forecast
area as a shortwave ejects from CA into the midwest. Widespread
showers and storms may develop in WY Thursday afternoon and move
into SD the latter half of the day. Currently the threat for
severe remains low, but might have an isolated cell or two
producing severe winds. Some localized areas may see 1-2 inches of
precip by Friday afternoon. An additional shortwave crosses the
region later this weekend, bringing another chance for isolated
showers and thunderstorms.

Temps begin to climb again over the weekend, with highs reaching
back into the 80s by Sunday.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening)
Issued At 514 PM MDT Wed Jun 23 2021

Isolated/scattered TS will persist this evening mainly along/south
of a line from KGCC-KPHP, and then move away from the area
overnight. Local MVFR conditions are possible with gusty erratic
winds near any storm. Additional storms will develop Thursday
afternoon with local MVFR conditions.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

DISCUSSION...Dye
AVIATION...Helgeson

Hazardous Weather Outlook
National Weather Service Rapid City SD
521 AM MDT Wed Jun 23 2021

SDZ001-002-012>014-024>032-041-072>074-WYZ054>058-071-241300-
Harding-Perkins-Butte-Northern Meade Co Plains-Ziebach-
Northern Black Hills-Northern Foot Hills-Rapid City-
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Pennington Co Plains-Haakon-Fall River-
Sturgis/Piedmont Foot Hills-Southern Meade Co Plains-
Hermosa Foot Hills-Northern Campbell-Southern Campbell-
Western Crook-Wyoming Black Hills-Weston-Northeastern Crook-
521 AM MDT Wed Jun 23 2021

This Hazardous Weather Outlook is for portions of western South
Dakota and northeastern Wyoming.

.DAY ONE...Today and Tonight

Isolated thunderstorms may develop this afternoon and evening.
Erratic gusty winds are possible near any thunderstorms.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Scattered to numerous showers and thunderstorms are possible on
Thursday and Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ042>044-046-047-049-241300-
Oglala Lakota-Jackson-Bennett-Mellette-Todd-Tripp-
521 AM MDT Wed Jun 23 2021 /621 AM CDT Wed Jun 23 2021/

This Hazardous Weather Outlook is for portions of south central
South Dakota...and southwestern South Dakota.

.DAY ONE...Today and Tonight

Isolated to scattered thunderstorms may develop this afternoon and
evening. Strong to severe storms, with large hail and damaging
wind gusts, are possible.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Scattered to numerous showers and thunderstorms are possible on
Thursday and Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

Special Weather Statement
National Weather Service Rapid City SD
809 PM CDT Wed Jun 23 2021

SDZ049-240200-
Tripp SD-
809 PM CDT Wed Jun 23 2021

...STRONG THUNDERSTORM OVER SOUTHEASTERN TRIPP COUNTY...

At 809 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles southwest of Wewela, or 9 miles northwest of Springview, moving
east at 10 mph.

Wind gusts of 50 to 55 mph will be possible with this storm.

Locations impacted include...
Millboro and Wewela.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4300 10016 4311 10009 4312 9954 4309 9953
      4299 9954
TIME...MOT...LOC 0109Z 279DEG 8KT 4291 9988

Sherburn

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
800 PM MDT WED JUN 23 2021

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

0740 PM     TSTM WND GST     4 SSE MILLBORO          43.01N  99.95W
06/23/2021  E60 MPH          TRIPP              SD   PUBLIC

&&

WFO UNR

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
803 PM MDT WED JUN 23 2021

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

0753 PM     TSTM WND GST     WEWELA                  43.01N  99.78W
06/23/2021  M57 MPH          TRIPP              SD   MESONET

&&

WFO UNR

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
813 PM MDT WED JUN 23 2021

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

0758 PM     NON-TSTM WND GST 3 NW WASTA              44.10N 102.50W
06/23/2021  M53 MPH          PENNINGTON         SD   MESONET

&&

WFO UNR

Special Weather Statement
National Weather Service Rapid City SD
824 PM MDT Wed Jun 23 2021

SDZ024-028-WYZ057-240315-
Northern Black Hills SD-Central Black Hills SD-
Wyoming Black Hills WY-
824 PM MDT Wed Jun 23 2021

...STRONG THUNDERSTORMS OVER SOUTHWESTERN LAWRENCE...WEST CENTRAL
PENNINGTON...NORTHEASTERN WESTON AND SOUTHEASTERN CROOK COUNTIES...

At 824 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles southwest of Sundance to 6 miles south
of Inyan Kara Mountain to 8 miles east of Osage. Movement was
northeast at 25 mph.

Wind gusts of 50 to 55 mph will be possible with these storms.

Strong thunderstorms will be near...
  Inyan Kara Mountain around 835 PM MDT.
  Sundance and Four Corners around 845 PM MDT.
  Mallo Camp around 850 PM MDT.
  Moskee and Buckhorn around 855 PM MDT.
  O'Neil Pass and Crooks Tower around 905 PM MDT.
  Cement Ridge Lookout around 910 PM MDT.
  Iron Creek Lake, Roughlock Falls and Savoy around 915 PM MDT.

This includes Interstate 90 in Wyoming between Mile Markers 179 and
202.

LAT...LON 4410 10437 4431 10452 4459 10422 4444 10398
      4415 10378 4399 10424
TIME...MOT...LOC 0224Z 221DEG 23KT 4430 10451 4413 10436 4401 10426

Sherburn

Special Weather Statement
National Weather Service Rapid City SD
1021 PM MDT Wed Jun 23 2021

SDZ001-012-024>026-028-031-072-073-WYZ054-056-057-071-240500-
Central Black Hills SD-Northern Foot Hills SD-
Sturgis/Piedmont Foot Hills SD-Harding SD-Rapid City SD-
Northern Black Hills SD-Butte SD-Pennington Co Plains SD-
Southern Meade Co Plains SD-Northeastern Crook WY-
Wyoming Black Hills WY-Western Crook WY-Northern Campbell WY-
1021 PM MDT Wed Jun 23 2021

...STRONG THUNDERSTORMS OVER SOUTHWESTERN HARDING...BUTTE...
SOUTHWESTERN MEADE...LAWRENCE...CENTRAL PENNINGTON...NORTHEASTERN
CAMPBELL AND NORTHEASTERN CROOK COUNTIES...

At 1021 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 11 miles west of Alzada to 4 miles northwest of
Belle Fourche to 2 miles north of Reptile Gardens. Movement was
northeast at 30 mph.

Wind gusts up to 50 mph will be possible with these storms.

Locations impacted include...
Rapid City, Spearfish, Sturgis, Belle Fourche, Lead, Sundance, Rapid
Valley, Ellsworth Air Force Base, Box Elder, Summerset, Black Hawk,
Deadwood, Whitewood, New Underwood, Johnson Siding, Newell, Nemo,
Hulett, Nisland and Piedmont.

This includes...
 Interstate 90 in South Dakota between Mile Markers 1 and 90.
 Interstate 90 in Wyoming between Mile Markers 184 and 207.

LAT...LON 4505 10351 4402 10251 4397 10346 4429 10434
      4500 10515 4499 10406 4530 10404
TIME...MOT...LOC 0421Z 219DEG 25KT 4506 10465 4471 10393 4402 10328

Helgeson