777
FXUS63 KUNR 290918
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
218 AM MST Sat Nov 29 2025

.KEY MESSAGES...

- Snow/blowing snow winds down today leaving cold weather (10-20F
  below normal) in it`s wake for the weekend
- Semi-unsettled weather expected next week with limited chances
  for impactful weather except for some upslope snow for the
  northern Black Hills

&&

.DISCUSSION...(Today Through Friday)
Issued at 216 AM MST Sat Nov 29 2025

08z surface analysis had low over south-central KS with inverted
trough into central SD and cold front behind it diving into
western NE. Water vapour loop had upper trough moving across the
northern/central Plains. Expansive area of snow per regional
radar/IR loops with back edge of best lift approaching the SD/WY
border. Disposition of upper trough continues to be the main
forecast concern.

Today, upper trough takes QG/frontogenetic forcing away this
morning with subsidence/drying moving from west to east across the
CWA this afternoon. Additional daytime snow accumulations will be
1-2 inches mainly over the northern Black Hills (upslope) and
south-central SD (synoptic forcing). The main story will be the
blowing snow due to northerly winds gusting to 30-45mph at times.
Have adjusted Winter Weather Advisory over south-central SD to end
at 29/21z as best winds hang on there the longest. Rest of
previous headline timing looks good. Temperatures won`t do much
today with readings near guidance/10-20F below normal.

Tonight, weak high pressure moves in setting the stage for a chilly
night with lows a few degrees below zero enhanced by fresh
snowcover. Minimum wind chills as low as -20F are foreseen.

Sunday, fast-moving shortwave dives through the Rockies with weak
QG-forcing/moisture brushing the southwest reaches of the CWA.
Have introduced PoPs since signal has been in guidance for a
couple of nights, although mean ensemble PoPs/QPF is low. Chilly
temperatures continue.

Next week looks semi-unsettled under northwest flow aloft and
weak wiggles. LREF guidance not painting anything too impactful.
Periodic bouts of light QPF may occur. Temperatures will moderate
except for Wednesday when a better kick of cold air moves through.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Saturday Night)
Issued At 948 PM MST Fri Nov 28 2025

Widespread IFR/MVFR conditions due to snow and blowing snow will
continue tonight into early Saturday morning, especially across
northeast WY and far western SD plains adjacent to the Black
Hills. Conditions will improve to VFR late Sat morning and
through the afternoon as winds decrease and snow ends.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 11 AM MST this morning for SDZ001-
     002-012>014-024>032-041>044-072>078.
     Winter Weather Advisory until 3 PM CST this afternoon for SDZ046-
     047-049.
WY...Winter Weather Advisory until 11 AM MST this morning for WYZ057-
     060.
     Winter Weather Advisory until 8 AM MST this morning for
     WYZ054>056-058-059.
&&

$$

DISCUSSION/KEY MESSAGES...Helgeson
AVIATION...13