617
FXUS63 KUNR 061702
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1002 AM MST Sat Dec 6 2025

.KEY MESSAGES...

- Chances for light snow today through Sunday morning.

- Warm and windy conditions early next week.

- More chances for precipitation for latter half of next week.

&&

.DISCUSSION...(Today Through Friday)
Issued at 309 AM MST Sat Dec 6 2025

Upper air analysis shows northwest flow continuing over the western
half of the CONUS, as it has been doing for some days now. A series
of embedded waves are crossing the northern Rockies into the
northern High Plains. At the surface, low pressure is developing
across southern MT through eastern WY, with breezy S/SE winds
responding across the western SD plains. KUDX radar shows light snow
gradually moving into the forecast area. The surface low will cross
SW/SCentral SD this morning as it strengthens, drawing colder air
back in from the NE. Light snow will continue today...mainly across
NW/central SD and the northern Black Hills. However, snow amounts
are expected to be light...an inch or less across most areas. Highs
will range from the mid 20s over NW SD to the lower 40s over far SW
SD. Snow will gradually dissipate this evening, but the next wave
and a warm front, will bring back more light snow to the area late
tonight through Sunday morning. Again, this could bring an inch
or so of snow, especially over NW SD and the northern Black Hills.
Lows will be in the single digits over NW SD and 20s over NE WY,
where warmer air will have worked in. Most areas will be dry by
Sunday afternoon, with highs in the 30s to lower 40s. Even warmer
air is expected on Monday as highs reach the 40s to lower 50s, along
with dry conditions. The next system then quickly pushes through
on Tuesday. Models have been showing highs even warmer than
Monday...approaching 60 in some spots. However, the ECM & GFS are
progged to bring a very strong cold front sometime in the afternoon,
which could affect highs if the timing ends up being earlier in the
day. Strong cold air advection and pressure rises could support
very strong winds, with gusts well over 60 mph. Will be keeping an
eye on this. The best chance for precip will again be over NW SD,
but would likely fall as rain, before the colder air can push in.
Active NW flow is progged to persist into the second half of the
week, with more unsettled weather, cooler temperatures, and breezy
winds.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Sunday)
Issued At 1001 AM MST Sat Dec 6 2025

MVFR with local IFR conditions in -SHSN will develop this
afternoon. Though snow will end this evening, MVFR/IFR CIGS will
remain overnight and continue into the next round of snow early
Sunday morning.

&&

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

$$

DISCUSSION/KEY MESSAGES...13
AVIATION...Smith