877
FXUS63 KUNR 301706
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1006 AM MST Sun Nov 30 2025

.KEY MESSAGES...

- Northwest flow will push several disturbances through the
  region for the next week
- Best chance of accumulating snow will be over the northern
  Black Hills

&&

.DISCUSSION...(Today Through Saturday)
Issued at 213 AM MST Sun Nov 30 2025

09z surface analysis had arctic high over the northern Plains.
Nighttime microphysics loop showed some stratus splattered about
the CWA. Temperatures under the stratus were in the single digits
above zero, but where skies have cleared, the mercury was low as
-17F. Water vapour loop depicted northwest flow over the region
with a shortwave over ID.

Today/tonight, ID shortwave drops south/southeast into the four
corners area. Weak lobe of mid-level moisture/weak QG-forcing over
the far southern reaches of the CWA will bring low chances of
light snow later this afternoon/tonight. MaxT adjusted several
degrees below guidance for today given fresh snow and increasing
cloud cover. Lows tonight will be near guidance.

Monday/Tuesday will see a warming trend ahead of upper trough
slipping through the northern Plains for Tuesday night/Wednesday.
Latest ensemble trends have increased PoPs Tuesday night, likely
due to stronger cold front passage leading to noticeably colder
temperatures for Wednesday. Pattern suggests upslope snowfall over
the northern Black Hills with several inches of snow possible
(LREF chance of >0.1" QPF >60%) if boundary layer moisture is
sufficient. Plains will see a bit of light snow too, but
confidence lower for impactful snow accumulations (LREF chance of
>0.1" QPF <30%). Thursday/Friday warms up again, but then another
shortwave moves through for the end of the week bringing a chance
of light snow, especially for the northern Black Hills.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1004 AM MST Sun Nov 30 2025

Local MVFR/IFR conditions due to patchy stratus and fog over the
South Dakota plains will improve by 20Z. Patchy light snow may
occur near the SD/NE border after 30/21z, but mainly VFR
conditions are expected.

&&

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

$$

DISCUSSION/KEY MESSAGES...Helgeson
AVIATION...Smith