233
FXUS63 KUNR 200434
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
934 PM MST Wed Nov 19 2025

.KEY MESSAGES...

-Seasonally mild and dry through the weekend

-Colder next week with some light snow possible

&&

.DISCUSSION...(This Evening Through Wednesday)
Issued at 1217 PM MST Wed Nov 19 2025

Mild Pac flow will continue into early next week as split flow
persists. Weak sfc trough progressing across the region today with
lingering fog in places across NW SD. Winds will shift NW behind
the front this afternoon with mild conds most places. Winds will
veer around to the SE overnight with ESE flow developing.
Lingering moisture with near saturated conds will support some fog
tonight, with the best chances across the SW half, esp along the
eastern slopes of the BH where upslope flow will be in place.
Hires models indicate fog and/or low clouds could linger there
through a large portion of the day with sustained moist ESE flow
and weak insolation. Hence, have knocked down temps INVOF of Rapid
City in addition to increasing cloud cover. WAA will ensue Thur
allowing for mild conds in the west, with mild conds most places
persisting through the weekend as zonal Pac flow continues over
the northern CONUS Rockies. Expect highs in the 50s and 60s in
this period. Pattern change will ensue next week as a large ridge
of high pressure in the north Pac dislodges a CP airmass into the
northern CONUS. This will ensue via a stronger cold front Mon
night into Tue. Some light snow will be possible Tue into Wed
across the western third, mainly northeast WY and the northern BH.
Additional precip chances later in the week will depend on where
the frontal boundary stalls next week.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Thursday Night)
Issued At 931 PM MST Wed Nov 19 2025

Local MVFR/IFR conditions due to stratus/fog over south-central SD
will continue through 20/12z. Areas MVFR/IFR conditions will
develop over portions of northeastern WY/western SD overnight,
persisting into the morning hours. The most best chance of LIFR
conditions will be over the higher elevations of the Black Hills.
Have introduced fog for the KGCC terminal to account and continued
the mention at KRAP. Not enough confidence to put in prevailing
at this point. Conditions will improve Thursday afternoon, but
might linger on the eastern slopes of the Black Hills.

&&

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

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...Helgeson