330
FXUS63 KUNR 021053
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
453 AM MDT Wed Jul 2 2025

.KEY MESSAGES...

- Hot with isolated storms through Thursday

- Scattered to numerous storms possible from west to east late
  Thursday through the holiday weekend.

&&

.DISCUSSION...(Today Through Tuesday)
Issued at 322 AM MDT Wed Jul 2 2025

Current water vapor imagery shows moisture associated with weak
ridge topping wave over MT/WY. Outflow boundary from storms over
NE is showing up on nighttime microphysics imagery along with
altocu developing overhead. The interaction between the outflow
and elevated instability could trigger a few showers/storms over
northwestern SD early this morning, however confidence is too low
to paint PoPs into the forecast at this time.

Upper ridge remains in place through today with low level thermal
ridge ensuring a very warm to hot afternoon. Highs this afternoon
will be in the 90s across the lower elevations of the plains
while the Black Hills will see temperatures in the low to mid 80s.
The ridge should also limit convective activity this afternoon,
though modest instability (HREF paints 60-80% probs for 1500+ J/kg
SBCAPE over the western SD plains) and terrain influences could
support an isolated storm or two over the Black Hills and the
higher elevations in northern WY. In terms of severe risk, not
anticipating anything widespread, however the modest instability
and favorable deep layer shear of 30-40kt would support an
isolated severe risk with wind and hail being the main concerns.
Ridge axis remains overhead on Thursday with even warmer
temperatures across the CWA. Highs across the plains will reach
into the 90s once again with some spots on the western SD plains
east of the Black Hills potentially reaching the triple digits.
There`s a higher chance for storms later Thursday as the ridge
axis shifts east and a shortwave crosses the region. However, CAPE
and shear won`t be as high which will limit severe potential.
Chances for storms continue through Friday, July 4th as a
shortwave crosses the region. However weak shear and modest CAPE
should limit severe potential.

Pattern becomes more zonal through the weekend with periods of
unsettled weather as disturbances ripple along the flow.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Thursday Morning)
Issued At 452 AM MDT Wed Jul 2 2025

Isolated TSRA may develop this afternoon over the Black
Hills/northeastern WY and persist into the evening hours as they
move northeast. Outside of TSRA, VFR conditions will prevail
through the period.

&&

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

$$

DISCUSSION/KEY MESSAGES...Wong
AVIATION...Wong