397
FXUS63 KUNR 302028
AFDUNR

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

.KEY MESSAGES...

- Minor chances for light snow this evening/overnight along Neb
  border

- Potential upslope snow event northern Black Hills Tuesday
  afternoon through Wednesday afternoon

- Northwest flow will keep temps below seasonal norms through the
  week

&&

.DISCUSSION...(This Evening Through Sunday)
Issued at 125 PM MST Sun Nov 30 2025

Latest analysis shows upper level split flow regime across much of
the CONUS, with weak shortwave ridging taking place in the
northern stream across southern Sask/Manitoba dropping into ND,
with a 500hpa shortwave trof/impulse in the southern stream
dropping into western WY with expansive cloud shield across
eastern WY into southwest SD. At the surface, the arctic high
pressure responsible for the chilly/record setting cold of this
morning was located across central SD. Low pressure was located in
northern UT with a surface trough nosing to the northeast into
south central WY. Weak radar returns are showing up across far
southwest SD, but scanning local webcams doesnt show much, so if
anything is reaching the ground, its flurries at best.

As the southern stream 500hpa wave conts to drop south through the
next 24 hours, weak 700hpa theta-e forcing remains along the SD/NE
border through 12z Monday. Moisture still remains pretty meager
with this system, but anticipating that the air will be cold
enough to wring anything out with minor forcing and ascent due to
wave passing to the south. With returns already being seen on
radar, will continue to minor pops along the border with little in
the way of accums/QPF.

Monday should be a quiet day with warmer...albeit still below
normal...temps. Tuesday is where the next forecast challenge
lies. Models are trending a bit cooler than previous runs, and
next upper trough drops through the region. LREF mean 2 meter
temps on Tuesday are now around a category cooler than current
forecast has going. Deterministic 850hpa temps are also a bit
cooler than when compared to 24 hours ago. Additionally, surface
cold front comes through a bit stronger and earlier than
previously thought, lending itself to a potential upslope snow
event for the northern Black Hills. LREF is showing total snow
accums probabilities of > 2 through 00z Thursday from 30-50% for
parts of the northern Black Hills. Minor accums are possible on
the plains...as probabilities of > 0.5 snow on the plains vary
from 20-30%. It will also become breezy/windy on backside of cold
front Tuesday afternoon through Wednesday with temps again
dropping on Wednesday.

Temperatures try to rebound a bit for Thursday and Friday, but
will fall again for the weekend as another impulse slides south
dragging a cold front with it. This will bring another shot of
light snow, especially to 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...Hintz
AVIATION...Smith