Spearfish, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

605
FXUS63 KUNR 281819
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1219 PM MDT Sun Jun 28 2026

.KEY MESSAGES...

- Severe storms possible tonight over western SD.

- Strong winds on Monday, with elevated to near-critical fire
weather conditions.

- Cooler Monday, but gradual warmup through the week.

&&

.DISCUSSION...(This Evening Through Sunday)
Issued at 1208 PM MDT Sun Jun 28 2026

Current Water Vapor and upper air models show the upper low
currently over north central MT, with southwest flow over the
forecast area. 17Z Surface analysis shows a boundary running from
northwestern SD down into southeastern WY. Winds are currently
light out of the south to southwest. Radar has some light returns
in northwestern SD moving northeast into ND.

Main concern in the near-term will be potential for severe
thunderstorms tonight into Monday morning. Mostly dry conditions are
expected this afternoon, but southeasterly LLJ ramps up this evening
into the overnight hours, bringing moisture into the region. Surface
low is expected to develop over northeastern CO and move
northeastward into the area by tonight. As low enters the region and
LLJ increases, strong to severe storms are expected to develop.
While we could see some showers/storms develop in the early evening,
HREF and HRRR show the stronger storms starting up between 03-06Z.
CAMS currently show strong to severe storms developing in
southwestern SD and the Black hills in this timeframe, then moving
northeast. Thermal profiles will support elevated storms with hail
being the main threat from these, however strong to severe wind
gusts cannot be ruled out.

Monday will be dry but windy, as strong mixing will support wind
gusts 45 to 55 mph. A Wind Advisory has been issued for much of
western SD, including the foothills late morning into the early
evening. Another shortwave is progged to move through the
central/northern plains late Tuesday into Wednesday, supporting
the potential for some showers/storms. Southwest flow continues
though the week, with weak disturbances prompting near daily
chances for at least isolated precipitation the latter half of the
week. Upper high in southeastern CONUS also builds over the week,
supporting a gradual warmup. Temperatures climbing into the 90s
will be possible Thursday through Saturday.


&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1116 AM MDT Sun Jun 28 2026

VFR conditions expected through 29/03z. Breezy southwest winds
will gust to 35kts over the northeastern WY plains. Scattered
tsra will develop this evening over western SD, especially after
29/03z. Any storm may bring IFR conditions, strong wind gusts, and
hail. Along/east of K2WX-KVTN after 29/06z, areas of IFR/MVFR
CIGS will develop.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 10 AM to 8 PM MDT Monday for SDZ012-013-
     025>027-030-031-041-042-072>076.
WY...None.
&&

$$

DISCUSSION...Dye
AVIATION...Helgeson