781
FXUS63 KUNR 181053
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
453 AM MDT Fri Oct 18 2024

.KEY MESSAGES...

- Cool and breezy today with chances for rain and higher elevation
  snow.

- Warmer by the end of the weekend with occasional disturbances
  bringing cooler conditions and low chances for precip through
  the mid week

&&

.DISCUSSION...(Today Through Thursday)
Issued at 148 AM MDT Fri Oct 18 2024

Bands of light precip continue to move across the region as upper
level front slowly crosses the region. Temperatures across the
CWA remain above freezing so precipitation has remained rain. As
the colder airmass pushes into the region, temperatures will
continue to drop off through the rest of tonight into tomorrow.
Some spots in the higher elevations of the Black Hills and
northeastern WY may get cold enough for snow with the best chances
for accumulation over the northern Black Hills. While snow
accumulations are generally expected to remain below an inch,
banding precip may result in locally higher amounts.

Modest CAA and 3 hr pressure rises on the order of 1-3 mb will
support breezy conditions across western SD today. Gusts of up to
40 mph are expected in some of our windier spots near the eastern
foothills. Winds will gradually diminish through the evening hours
as the system exits the region and high pressure moves in.

Upper trough to our west will dig south with cutoff low
developing over the desert SW. This low will slowly meander its
way across the Rockies before entering the central plains by early
next week. Deterministic runs differ slightly on the exact
location of this upper low by the time it reaches the central
plains on Monday, though there`s generally good consensus on the
low remaining just to our south as it tracks across the plains. If
the low does manage to track further north than the most recent
deterministic model runs indicate, we could see more chances for
light precip by Monday, especially across southwestern into south
central SD.

As the upper low approaches, shortwave ridging will build into
the region which will result in a gradual warming trend.
Temperatures by Sunday will be back into the mid to upper 70s,
especially across western into central SD. Cool front associated
with aforementioned upper low will cross the region by Monday
bringing in cooler temps for the midweek. Deterministic runs hint
at another disturbance crossing the region by the middle of next
week with cooler weather and slight chances for precip.

Ensemble cluster analysis depicts ridge building back into the
northern plains by the end of next week with potentially warmer
and drier conditions as a result.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Saturday Morning)
Issued At 449 AM MDT Fri Oct 18 2024

Low stratus will continue to spread across much of northeast
Wyoming and western South Dakota this morning with scattered
shower activity. This will result in widespread MVFR/IFR
conditions. There may be some snow at higher elevations of
northeastern Wyoming (including KGCC terminal) and the Black
Hills through this morning LIFR conditions. Lower stratus with
MVFR/local IFR conditions will spread into central south central
South Dakota this morning through early afternoon. MVFR/IFR
conditions will linger into tonight for much of the area.

&&

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

$$

DISCUSSION/KEY MESSAGES...Wong
AVIATION...7