799
FXUS63 KUNR 072315
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
515 PM MDT Tue Oct 7 2025

.KEY MESSAGES...

- Above average temperatures return Wednesday through Saturday
  with dry conditions.
- Gusty southerly winds Wednesday with breezy conditions Friday
  into the weekend.
- Cold front will usher in cooler temperatures and precipitation
  chances late weekend.

&&

.DISCUSSION...(This Evening Through Tuesday)
Issued at 132 PM MDT Tue Oct 7 2025

Upper level analysis shows upper trough axis pivoting through the
Upper Midwest with ridging building over the western US. Water
vapor imagery shows another Pacific Coast trough along the British
Columbia coast and an upper level high pressure building over SE
Texas. This high pressure will continue to build over the southern
US as the Pacific trough digs southward, amplifying the upper
ridge over the region through the week. Temperatures will trend
warmer today through Saturday as south-southwesterly flow
dominates, with widespread 70s to low 80s across the plains
Wednesday and beyond.

The main weather concern over the next 24-48 hours will be strong
southerly winds as a low-level jet develops Wednesday afternoon
into early morning Thursday. The NBM is rather bullish (50th
percentile gusts of 50+ mph and mean wind gusts near 55 mph)
across south-central SD, which while possible, seems over done for
a warm air advection regime. Forecast soundings do show 35-40 knot
winds atop the mixed layer Wednesday afternoon and evening, which
may yield advisory level wind gusts. Enough uncertainty remains on
the max wind potential, so will hold off on any wind headlines at
the moment.

The Pacific Coast trough will continue to deepen, becoming a
closed low Wednesday with upper ridging/high pressure over the
central US. A compact shortwave trough will eject through
southern Canada Thursday, dropping through the Northern Plains and
Upper Midwest Friday. A weak cool front/surface trough will sweep
through the forecast area, although temperatures will remain in
the 60s and 70s Friday.

Active southwesterly flow will persist into the weekend with some
precipitation potential. Cooler temperatures and more active
weather is expected as the upper trough pivots through the western
US Sunday into early next week.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Wednesday Evening)
Issued At 513 PM MDT Tue Oct 7 2025

Look for southerly winds to become gusty overnight as low level
jet intensifies. Otherwise VFR conditions are expected through the
valid TAF period.

&&

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

$$

DISCUSSION/KEY MESSAGES...SE
AVIATION...Hintz