343
FXUS63 KUNR 081048
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
348 AM MST Sat Nov 8 2025

.KEY MESSAGES...

- Accumulating snowfall over the Black Hills today with snow
  totals of 3 to 6 inches possible, especially at elevations over
  5000 ft. Gusty winds will cause blowing snow at times.

- Strong northwest winds will develop over western SD this morning
  and persist into the afternoon with gusts of 45 to 60 mph
  possible

- Another round of light snow possible tonight with minor
  accumulations (generally less than an inch) across the foothills

&&

.DISCUSSION...(Today Through Friday)
Issued at 305 AM MST Sat Nov 8 2025

Water vapor imagery shows well defined low over eastern MT
pushing to the southeast into the Dakotas. Initial cold front and
round of precip is mostly out of the CWA with a band of light
precip currently over south central SD. Winds have calmed down as
the primary cold front exits the CWA, most stations are reporting
northwest winds of 5 to 15 mph with gusts of up to 25. The second
cold front is currently pushing into the CWA with webcams showing
light rain has begun across portions of northwestern SD.
Temperatures in northwestern SD are still in the upper 30s to low
40s so precip in the lower elevations should initially start off
as rain or a rain/snow mix before transitioning to light snow as
colder air filters into the region. The Black Hills and
northeastern WY should remain cold enough for precip to be all
snow.

Bulk of precip will move through the western SD plains this
morning with a few lingering snow showers in the afternoon as the
low slides to the southeast. Moist northwest flow (Froude numbers
>1 and 0-2km RHs >90%) will support upslope snow in the northern
Black Hills through most of today. HREF Grand Ensemble guidance
paints 80+% probs for liquid equivalent precip through today to
exceed 0.25" with most deterministic models showing around 3-6" of
snow accumulation across the higher elevations of the Black
Hills. The snow in conjunction with gusty winds will cause blowing
snow at times through the day, which will create hazardous travel
conditions. Another quick round of precip is possible across the
northern Black Hills and foothills later tonight as strong 300mb
jet streak moves overhead. Additional accumulations should be
light but the Sturgis/Piedmont and Rapid City foothills could pick
up the first (light) snow accumulations of the season tonight.

The other impact with this system will be strong northwest winds,
especially over the western SD plains. Modest 3 hr pressure rises
of 3-5 mb behind the front and strong CAA will support strong
winds over much of the western SD plains. Belt of strong 40-55kt
winds at H825-H750 will move over the western SD plains this
morning (~12z- 18z) with the core of the strongest winds extending
from the Belle Fourche area southeast into the Badlands. There`s
still some question as to if these winds will be able to mix to
the surface given the timing of the front. However, widespread
advisory level gusts expected with the potential for gusts of up
to 50kt possible in the squeeze zones north of the Black Hills.
There`s some signal that advisory level gusts could extend as far
east as Todd and Mellette Counties in south central SD but have
opted to hold off on expanding the wind advisory to include those
counties.

Cold airmass will push into the region later today into Sunday
with lows tonight in the teens to 20s and wind chills dipping into
the single digits towards central SD. Chilly day on Sunday with
highs in the mid 30s to mid 40s, coldest temps will be across
northwestern into south central SD and the Black Hills. After
another cold night across the CWA, temperatures will trend warmer
through early next week as upper level ridge builds in the western
CONUS. Expecting mainly dry and mild weather next week as
northwest flow sets up over the CWA.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Sunday Morning)
Issued At 346 AM MST Sat Nov 8 2025

Gusty NW winds are expected this morning behind a strong cold
front, with winds sustained at 20-30 knots and gusts 35-50+ knots.
MVFR CIGS and light snow showers are expected, mainly across NW
to central SD. IFR/LIFR conditions and -SN will persist across the
northern and Wyoming Black Hills through the day today.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 4 PM MST this afternoon for SDZ001-002-026-
     027-030-041-074-075-078.
     High Wind Warning until 4 PM MST this afternoon for SDZ012-013-
     031-072-073.
     Wind Advisory until 4 PM MST this afternoon for SDZ014-032-
     042>044-076-077.
     Winter Weather Advisory until 6 PM MST this evening for SDZ024.
     Wind Advisory until 2 PM MST this afternoon for SDZ025.
WY...Winter Weather Advisory until 6 PM MST this evening for WYZ057.
&&

$$

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