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000
FXUS63 KUNR 291108
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
508 AM MDT Fri Sep 29 2023

.DISCUSSION...(Today Through Thursday)
Issued at 306 AM MDT Fri Sep 29 2023

Current surface analysis shows cool front east and south of the
forecast area, with weak high pressure to the north. Upper level
analysis shows southwesterly flow across the region, with broad
trough across southwest Canada and the Pacific NW. A shortwave
disturbance passing through the area continues to bring isolated
to scattered showers and thunderstorms. The bulk of the activity
is across far northeast WY into northwest SD and toward south
central SD, where a few stronger storms have produced some small
hail. Temps are mostly in the 50s and lower 60s with light winds.

Showers and a few storms will continue to track northeast across
eastern and northern portions of the area early this morning, likely
exiting the forecast area around sunrise. Skies will become partly
cloudy to mostly sunny for the rest of the day with highs in the
upper 60s and 70s.

Warmer air will build into the region over the weekend as negatively
tilted ridge builds back over the Plains, ahead of digging trough
across the western US. Highs will reach the mid 70s to mid 80s
Saturday, with 80s to lower 90s in most areas on Sunday. Record
highs for most areas on Sunday are in the 90s, but a couple of
places could at least approach their record values. With the warmer
air, south to southeast winds will increase over the weekend,
becoming rather gusty in some areas, especially on Sunday across
south central SD where gusts over 40 mph are likely. Chances for
showers and storms will start to increase toward Sunday evening as
energy ejects out of the trough to the west and into the high
Plains. If storms get going early enough during the late day and
evening, there would be potential for isolated stronger storms with
some MUCAPE and increasing shear expected.

The first half of next week looks rather unsettled and cooler as the
trough pushes across the Rockies and Plains Monday through
Wednesday. Daily chances for showers and a few storms can be
expected, with temps dropping back to near to slightly below average
levels by Tuesday and Wednesday, along with brisk winds. A drier
pattern is expected for the latter half of the week, but will watch
for the potential of a clipper system passing through at least parts
of the northern Plains into the upper Midwest sometime Thursday into
Friday. This could bring another shot of cooler air, with potential
for frost or possibly near freezing temps toward Friday morning and
especially Saturday morning if it tracks far enough south across the
region.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Saturday Morning)
Issued At 507 AM MDT Fri Sep 29 2023

VFR conditions are expected through the TAF period.

&&

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

$$

DISCUSSION...26
AVIATION...MLS