238
FXUS63 KUNR 202022
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
122 PM MST Thu Nov 20 2025

.KEY MESSAGES...

-Seasonally mild and dry through the weekend

-Turning colder next week with some light snow possible

&&

.DISCUSSION...(This Evening Through Thursday)
Issued at 117 PM MST Thu Nov 20 2025

Mild Pac flow will continue into early next week as split flow
persists. Sfc front has stalled over the SW third. This supported
an area of low clouds and fog this morning with a large portion
of the fog and clouds having since burned off. The same area
across the SW third to half will likely see low clouds and patchy
fog once again tonight as LL moisture will remain in place with
ESE upslope flow. WAA will ensue overnight into Fri allowing for
mild conds most areas Fri, with mild conds most places persisting
through the weekend as zonal Pac flow continues over the northern
CONUS Rockies. Any morning clouds and fog will dissipate Fri
morning as dry air mixes down from aloft. Expect highs mainly in
the 50s and 60s through Monday, with some 40s over northeast areas
Friday. 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, with breezy NW winds expected 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 sets up next
week as impulses ride SE along the baroclinic zone.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Friday)
Issued At 958 AM MST Thu Nov 20 2025

Local MVFR and IFR conditions in low clouds and fog will persist
this afternoon across portions of northeastern Wyoming and
southwestern South Dakota. VFR conditions are expected across
northwestern and south central South Dakota. Areas MVFR/IFR/LIFR
conditions will redevelop this evening and continue through Friday
morning.

&&

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

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...Smith