709
FXUS63 KUNR 022110
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
210 PM MST Tue Dec 2 2025

.KEY MESSAGES...

- Snow continues into Wednesday morning, better chances for
  accumulations in the northern Black Hills.

- Colder temperatures for Wednesday, followed by a warming trend.

- Active pattern brings multiple chances for light precipitation.


&&

.DISCUSSION...(This Evening Through Tuesday)
Issued at 131 PM MST Tue Dec 2 2025


Current Water Vapor and upper air analysis shows the upper trough
over western Canada dipping into the PAC NW, with northwest flow
over the FA. Surface analysis shows low over northeastern ND, with
the frontal boundary stretching into northeastern MT. Current
radar shows scattered areas of light precipitation over western SD
this afternoon. Temperatures currently sit in the 30s to low 40s
across the plains, while Black Hills temperatures are in the 20s
to mid 30s.

Areas of light precipitation will continue this afternoon, however
the better QPF chances come this evening and tonight as the
frontal boundary moves through the CWA. Weak forcing will limit
accumulations over the plains. Upslope enhancement over the
northern Black Hills will bring the best snow accumulation
chances, with HREF probability of QPF>0.5" in the 50-70 percent
range over this area. WSSI shows 30-50% probability for minor
impacts in the northern Black Hills through Wednesday morning. No
changes to the current Winter Weather Advisory in effect for the
northern hills, with 2-5 more inches possible over the next 18
hours. Precipitation will diminish late Wednesday morning, though
some weak upslope in the Black Hills may continue a little longer.

Expect a 10-15F drop in temperatures for Wednesday following
tonight`s cold frontal passage. Mostly dry conditions are
expected Wednesday afternoon through Thursday afternoon, before
the next disturbance moves down out of Canada through the Dakotas.
Overall synoptic pattern will limit moisture from these
disturbances, with the better chances for accumulations remaining
in the upslope Black Hills area. Following this cooler Wednesday,
models point to a warming trend late in the week. There is some
model divergence, however it may be possible we reach back into
the 50s early next week.


&&

.AVIATION...(For the 18Z TAFS Through 18Z Wednesday)
Issued At 1027 AM MST Tue Dec 2 2025

Areas of MVFR ceilings with light rain and snow will continue
across much of the area this afternoon. More widespread
precipitation chances overspread the area late this afternoon
from west to east with widespread MVFR/IFR conditions developing,
persisting into the overnight hours. LIFR conditions will occur
over the higher elevations of the Black Hills tonight. Conditions
will slowly improve from west to east by late Wednesday morning.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 6 AM MST Wednesday for SDZ024.
WY...Winter Weather Advisory until 6 AM MST Wednesday for WYZ057.
&&

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...15