Spearfish, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

293
FXUS63 KUNR 250419
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1019 PM MDT Sun May 24 2026

.KEY MESSAGES...

- Warm through Memorial Day with isolated afternoon
  thunderstorms, mainly over the Black Hills

- Chances of showers and thunderstorms will increase Tuesday night
  and continue through the rest of the week

&&

.UPDATE...
Issued at 926 PM MDT Sun May 24 2026

No big changes to the inherited forecast.

Still expecting a very warm day tomorrow with morning lows in the
mid 40s to mid 50s and afternoon highs in the mid 80s to mid 90s.
Warmest temps will be in the SD plains with the cooler temps (but
still above average) in NE WY. These warm temps will linger into
Tuesday.

One change was to extend the timing of Monday`s showers to more
closely match what happened today. Hi-res models and the EURO
ensemble support this.

Wind speeds through Monday morning look to be on the lighter side
with slightly stronger winds, around 10 to 20 mph, in the
afternoon. Monday night`s winds will decrease in speed before
really ramping up Tuesday. Tuesday`s wind speeds could reach near
25 mph in the afternoon with gusts around 35 to 45 mph in W SD.
Speeds like that with temps in the 80s & 90s and RH down to
around 20% could allow fire weather to creep back into the area.
Stay tuned.

&&

.DISCUSSION...(This Evening Through Sunday)
Issued at 1256 PM MDT Sun May 24 2026

Upper flow is transitioning this afternoon from WNW to near zonal.
Vis sat shows high based cu has developed across NE WY through the
Black Hills. Still can`t rule out an isolated shower or thunderstorm
over the Hills late this afternoon, but most areas will remain dry.
Overnight advection will bring warmer temps to the area on Memorial
Day. Highs will reach the upper 80s to lower 90s. Again, can`t rule
out an isolated afternoon shower or storm over the Hills, but
otherwise quiet weather is expected. Models continue to show a deep,
stationary upper low across in the vicinity of the Great Basin and
northern California through the middle and latter part of this week.
Good moisture transport from the Gulf sets up over the central to
northern Plains, bringing PWATs ranging from 125-175% of normal. The
moisture will be available...it`s just a matter of where the best
forcing sets up. The ECM continues to focus on the Dakotas while the
GFS targets WY, though there has been some shift eastward later in
the week closer to the ECM. Will continue to monitor the trends.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Monday Night)
Issued At 1018 PM MDT Sun May 24 2026

VFR conditions are expected through the forecast period. Isolated
showers/storms may be possible Monday afternoon and evening,
however low confidence on them affecting the TAF sites.


&&

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

$$

UPDATE...GS
DISCUSSION/KEY MESSAGES...13
AVIATION...Dye