946
FXUS63 KUNR 081732
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1032 AM MST Wed Jan 8 2025

.KEY MESSAGES...

- Warmer today
- Cold front with gusty northwest winds and snow tonight/early
  Thursday. 60-80% probability of 3-6" of snow in the northern
  Black Hills and less than 20% probability of an inch on the
  plains.
- Next chance of snow along with gusty northwest winds Saturday.

&&

.DISCUSSION...(Today Through Tuesday)
Issued at 207 AM MST Wed Jan 8 2025

Current surface map shows high stretching from Hudson Bay into the
central CONUS with surface trough/warm front across central
Montana into the Black Hills. A wide range of temperatures across
western South Dakota with a few valley locations around the
Badlands ranging from -5F to -10F and downslope areas around the
Black Hills 20F to 25F above. Robust warm advection continues
today with highs in the 30s to lower 40s...warmest in downslope
areas of the Black Hills. Fast moving clipper crosses the area
tonight/early Thursday. 3-4mb/3hr pressure rises/CAA supports
gusty northwest winds. Widespread gusts of 35 to 45 mph likely
(70-90%) on the plains of western South Dakota with a chance
(30-50%) of gusts 45 to 50 mph on the plains just east-northeast
of the Black Hills. Along with the winds, a quick shot of forcing
and marginal moisture may bring a few hours of light snow on
plains. Snowfall accumulations on the plains will generally be
less than an inch (0-20% of more than an inch). Meanwhile
Froude/RH favorable for a 12-15 hour period of northern Black
Hills upslope enhancement later this evening through Thursday
morning. With a 60-80% probability of 3-6" of snow, have issued a
Winter Weather Advisory for the Bear Lodge and Northern Black
Hills. For the plains, there should be a period tonight/early
Friday where winds will reach advisory criteria. The combination
of current snow cover and new/falling snow may bring some blowing
and drifting snow issues which might be better covered with a
Winter Weather Advisory. Since the impacts will be overnight
tonight/early Thursday (impacting Thursday AM commute), will hold
off on headlines and let day shift evaluate further.

Northwest flow aloft continues through early next week. Next
clipper dives through the area Saturday with another round of
wind and light snow on the plains and upslope enhanced snow for
the northern Black Hills.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Thursday)
Issued At 1026 AM MST Wed Jan 8 2025

VFR conditions are generally expected through the daytime hours
today. Breezy west to southwest winds will develop on Wednesday
across portions of northeast WY and western SD. A cold front will
arrive Wednesday evening, with increasing chances for light snow
and gusty northwest winds. VFR conditions will drop to MVFR/IFR
most places overnight with isolated LIFR conditions developing due
to blowing snow and snow showers.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 8 PM this evening to 11 AM MST
     Thursday for SDZ024.
WY...Winter Weather Advisory from 8 PM this evening to 11 AM MST
     Thursday for WYZ057.
&&

$$

DISCUSSION/KEY MESSAGES...7
AVIATION...Dye/Schultz