398
FXUS63 KUNR 271722
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1022 AM MST Tue Jan 27 2026

.KEY MESSAGES...

- Seasonably mild for northeastern WY into southwestern SD through
  most of this week

- Increasing chances of light snow in the latter half of the week

&&

.UPDATE...
Issued at 519 AM MST Tue Jan 27 2026

KUDX radar is showing light returns across the northern Black
Hills area, and webcams confirm flurries are reaching the ground.
Have updated the forecast to add mention of flurries through 18z.
No accumulation is expected.

&&

.DISCUSSION...(Today Through Monday)
Issued at 248 AM MST Tue Jan 27 2026

Water vapor imagery shows upper ridging moving onshore the Pac
Coast while NW flow continues across the central CONUS. A series of
upper waves are crossing the northern/central Rockies, bringing
mid/highs clouds to the intermountain west into western portions of
the CWA. Surface obs show high pressure centered over Sask extending
into the Dakotas. The frontal boundary is draped over the CWA with
temps ranging from the 20s over NE WY to single digits over NW SD.
Dry weather will continue today, with highs ranging from the low 40s
over NE WY to lower/mid 20s over central SD. Varying levels of
mid/high clouds will remain today as 750mb warm advection/weak
isentropic lift jogs the baroclinic zone eastward toward central SD.
Precip is not expected today nor Wednesday. With the front stalled
across central SD, highs tomorrow will be similar to today, but the
Black Hills area will be slightly warmer...upper 30s to 40s. There
will be little movement to the upper level pattern as a Rex Block
sets up over the Pac NW/northern Rockies. Models are still trying to
gain consistency with solutions for the second half of the week, but
it has been trending snowier. Strong high pressure will again drop
down into the Dakotas Wed night into Thu, pushing the front back
westward into the CWA as a backdoor cold front. Low level frontal
forcing combining with mid/upper level support from a shortwave
would bring increasing chances of snowfall to the area. As of now it
looks like two rounds of light snow...one on Thursday, then a second
round on Friday as a another wave crosses the region. Unsure of snow
amounts at this time, but best guess is this will be up to 3 inches
over a 48-hour period.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Wednesday)
Issued At 1020 AM MST Tue Jan 27 2026

VFR conditions are expected through the TAF period.

&&

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

$$

UPDATE...13
DISCUSSION/KEY MESSAGES...13
AVIATION...15