Expires:No;;741652
FXUS63 KUNR 032311
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
411 PM MST Sat Jan 3 2026

.KEY MESSAGES...

- Gusty westerly downslope winds late tonight/early Sunday
- Warm front moves through tonight with record/near record 
  temperatures for some Sunday
- Mild start to the week Monday, but eventually becoming more 
  seasonal an an upper trough moves through

&&

.DISCUSSION...(This Evening Through Saturday)
Issued at 125 PM MST Sat Jan 3 2026

20z surface analysis had cold front from southeast MT into 
southeast SD. North of the front, temperatures in the 20s/30s with
a stratus/fog deck over the far northeastern reaches of the CWA.
Southwest of the front, 40s common with a smattering of 50s. 
Cirrus-filtered sunshine for the rest of the CWA. Water vapour 
matinee had upper ridge building into the northern plains with a 
jet streak over NV heading our way.

Tonight/Sunday, jet streak races northeast which will push cold 
front back through the CWA as a warm front. It should scour low 
level moisture away from northwestern SD, especially given 
westerly flow and better mixing than last couple of days. Record 
temperatures in jeopardy tomorrow per most probabilistic guidance 
(50-80% chance from Rapid City south/southeast). Before warm front
moves through, stratus/fog deck over northeastern reaches of the 
CWA may ooze southwest tonight with forecast painted to account. 
Another effect of the warm front will be increased boundary layer 
flow (25-45kts) with 4mb pressure gradient across the Black Hills.
Bufkit soundings as well as HREF guidance (50% chance >45mph) 
suggests a period of gusty winds into Sunday morning across parts 
of northeastern WY/southwestern SD. Have hoisted Wind Advisories 
to account with the higher elevations targeted. Lows tonight will
be near guidance, expect for the downslope areas of the Black 
Hills where readings will be above guidance. Temperatures Sunday 
near guidance.

Next week, upper ridge slowly breaks down through mid-week as 
flow splits and becomes westerly. We'll see a couple of weak 
disturbances, but with low PoPs and wind shifts. Temperatures 
will be a bit cooler. Better-defined upper trough moves for for 
the end of the week with limited moisture and cooler temperatures,
dropping to seasonal normals by Friday. Moisture looks limited 
with trough winding up east of the CWA.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Sunday Evening)
Issued At 411 PM MST Sat Jan 3 2026

MVFR/IFR conditions from low clouds and fog will remain across
northwest SD. VFR conds are expected elsewhere for the remainder
of the valid terminal forecast period. Across northeast WY/the
Black Hills and foothills, gusty southwest winds will develop late
this evening and continue through the overnight hours. Winds 
could gust as high as 40kts at times. 

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 3 AM to 8 AM MST Sunday for SDZ025-026-074.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Helgeson
AVIATION...Wong