078
FXUS63 KUNR 081109
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
509 AM MDT Wed Oct 8 2025

.KEY MESSAGES...

-Mild and mostly dry the rest of the work week with temps above
 normal

-Breezy at times in the period, especially today toward central
 SD

-An upper level trough and cold front will bring chances for rain
 this weekend with cooler weather to start next week

&&

.DISCUSSION...(Today Through Tuesday)
Issued at 108 AM MDT Wed Oct 8 2025

Upper low will stall in the Pac NW this week and support
downstream ridging over the central CONUS. This will allow for
mainly dry weather and above normal temps. Expect highs in the 70s
and a few 80s the rest of the week. Southerly LLJ will develop
today as a lee-side trough deepens, supporting breezy weather
across the region. Near adv level winds are expected in scentral
SD with winds gusting over 40 mph there. An upper trough will top
the ridge and drop a weak backdoor cool front into the area Thurs.
This will support a slightly cooler day Friday, esp over
northeast areas, but temps will still be above normal. Monsoon
moisture accentuated by a tropical system off the coast of Baja
will get caught up in SW flow aloft and may support a few showers
later in the day Friday and Friday night. Not expecting a whole
lot with this system, but a few places may see a few hundredths.
Pac NW upper trough will begin to shift east by this weekend,
phasing with a deeper northern stream trough. This will allow for
local shortwave ridging Sat, supporting the warmest day in the
period as temps will climb into the 80s many places. It will also
be breezy per south winds ahead of the expected cold front. Cold
front will then move into the area by Sun, with increasing chances
for showers Sat night into Sunday. Cooler and unsettled weather
looks likely next week, with mean upper level troughing progged
over the western and central CONUS. Confidence drops off wrt to
details after Monday given model indications for potential flow
blocking over both the east and west coasts per closed upper
troughs.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Thursday Morning)
Issued At 507 AM MDT Wed Oct 8 2025

VFR conditions through the forecast period. Gusty southerly winds
can be expected on the SD Plains today, with gusts over 35 knots
possible, strongest toward central SD.

&&

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

$$

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