Damaging Winds in Wyoming, June 26, 2026

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
135 PM MDT Fri Jun 26 2026

.KEY MESSAGES...

- Isolated to scattered severe thunderstorms possible across much
  of the area this afternoon/evening. Main hazards will be large
  hail (1+" in diameter) and damaging wind gusts (60+ mph)

- Isolated to scattered severe thunderstorms possible again on
  Saturday with the highest risk across northwestern SD. Main
  hazards will be very large hail (1 3/4+" in diameter) and
  significant wind gusts (74+ mph). An isolated tornado also can't
  be ruled out.

- Isolated severe storms possible on Sunday across much of
  northeastern WY into western SD.

&&

.DISCUSSION...(This Evening Through Friday)
Issued at 135 PM MDT Fri Jun 26 2026

Visible satellite shows cumulus struggling to develop over the
Black Hills with midlevel clouds moving in from northeastern WY.
Current mesoscale analysis shows nose of 500-1000 J/kg ML CAPE
pushing into southwestern SD with 150-200 J/kg CIN. The 18z
sounding from KUNR shows ~1000 J/kg SB CAPE with a strong cap.
While short range model guidance shows increasing ML CAPE over
western SD into northeastern WY through this afternoon with 1500-
2000 J/kg ML CAPE over much of western SD into portions of the
Black Hills by later this afternoon into this evening, 500 mb
height rises and warm 700 mb temps may limit convective
development across much of our CWA. Most recent CAMs show
convection developing over the higher terrain in WY and moving
into northeastern WY by later this afternoon. Inverted-V profiles
and low level curvature in forecast hodographs indicate a damaging
wind and large hail threat. Storms will push east into western SD
by this evening, moving out of the CWA by midnight.

Severe potential continues on Saturday as a shortwave and
attendant lee sfc trof/low moves through the region. As the sfc
trof deepens over western SD, axis of 2500-3000 J/kg ML CAPE will
develop across much of the western SD plains and northwestern SD.
The greater shear of 35-45KT will be displaced further west of the
greatest instability, though there is some overlap over
northwestern SD. Current CAMs show discrete storms firing over
southeastern MT and moving into northwestern SD by Saturday
evening. These storms will be capable of very large hail (greater
than 1 3/4") and significant wind gusts (74+ mph). Tornado threat
is low but not zero and an isolated tornado is certainly possible
with any discrete supercells that form.

Unsettled southwest flow continues over the CWA through Sunday as
the western US trof deepens. This will result in chances for
storms (some may be strong to severe) later Sunday into Monday.
Additionally, temperatures will continue to warm through this
weekend with highs in the 80s to 90s by Saturday and Sunday. After
a slight cool down on Monday, ensemble guidance is signaling much
warmer weather with daily chances for isolated storms later in
the week as a ridge builds to our east.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1114 AM MDT Fri Jun 26 2026

Areas of MVFR CIGS from K2WX-KD07-KICR will dissipate this
afternoon. Scattered TSRA will develop over northeastern
WY/northern Black Hills by 26z/21z (including the KGCC terminal) and
then track east/northeast with local IFR conditions, including
strong erratic winds/hail. Chance of TSRA for KRAP is lower, but
did include a prob30 to account. IFR CIGS will develop along/east
of a line from KD07-KICR later tonight. Outside of these areas,
expect VFR conditions.

&&

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

DISCUSSION...Wong
AVIATION...Helgeson

Special Weather Statement
National Weather Service Rapid City SD
312 PM MDT Fri Jun 26 2026

WYZ055-262145-
Southern Campbell WY-
312 PM MDT Fri Jun 26 2026

...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL CAMPBELL COUNTY
UNTIL 345 PM MDT...

At 312 PM MDT, Doppler radar was tracking a strong thunderstorm 12
miles west of Savageton, or 29 miles northwest of Wright, moving
northeast at 30 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Savageton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 4409 10601 4419 10580 4419 10578 4387 10559
      4380 10602 4382 10602 4382 10601
TIME...MOT...LOC 2112Z 244DEG 24KT 4392 10601

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 TO 55 MPH

Wong

Special Weather Statement
National Weather Service Rapid City SD
428 PM MDT Fri Jun 26 2026

WYZ054-055-058-262300-
Northern Campbell WY-Southern Campbell WY-Weston County Plains WY-
428 PM MDT Fri Jun 26 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN WESTON AND EAST
CENTRAL CAMPBELL COUNTIES UNTIL 5 PM MDT...

At 428 PM MDT, Doppler radar was tracking a strong thunderstorm over
Belle Ayr Mine, or 16 miles southeast of Gillette, moving northeast
at 25 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Caballo Mine, Cordero Rojo Mine, Coal Creek Mine and Belle Ayr
  Mine.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 4393 10541 4410 10549 4428 10514 4419 10508
      4418 10508 4418 10507 4401 10497
TIME...MOT...LOC 2228Z 239DEG 21KT 4406 10536

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Wong