Spearfish, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

194
FXUS63 KUNR 150458
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1058 PM MDT Tue Oct 14 2025

.KEY MESSAGES...

-Unsettled through Thursday

-Fog and drizzle tonight, mainly on the SD Plains, possibly
 lingering through the day in the eastern Black Hills foothills

-Good chance of rain and a few TS Wed night, esp northeast WY and
 far Western SD

-Drying out this weekend, with seasonal temps

&&

.DISCUSSION...(This Evening Through Tuesday)
Issued at 134 PM MDT Tue Oct 14 2025

Deep upper trough over the western CONUS will support unsettled
weather the next couple days. The main upper trough will begin to
move into the region tonight with very moist southerly flow
developing. ESE saturated upslope flow will support areas of fog
and drizzle tonight, esp along the eastern slopes of the Black
Hills where measurable precip from drizzle can be expected. There
will also be passing showers per ongoing unsettled SW flow aloft
as weak impulses traverse the flow. ESE moist flow will persist
Wed with fog potentially lingering through most of the day along
the eastern BH foothills. Have added a mention through the day
there. Otherwise, the main area of lift and associated jet streak
will shift toward the region Wed evening. This will support a
cluster of showers and TS over the western third. Given dynamic
forcing from the jetlet, ample deep layer moisture, and steepening
mid-level lapse rates, a few strong cells will be possible with
gusty winds and hail. PW`s will be over an inch in many areas,
which will also support locally heavy rain where cells persist or
train. Still come uncertainty as to where the band of best
forcing/convergence will setup, but most hires models favor
between northeast WY and far western SD. Thus, that`s where the
highest pops reside. Showers and isolated TS will linger through
Wed night as few weaker impulses traverse the flow. Dry slot will
push into the region later Thur morning and afternoon with things
drying out and winds shifting westerly. A few showers will be
possible Thu night, but it`s looking more dry attm. Drier and
slightly cooler air will move into the region for Fri and esp Sat.
However, temps will still be around or above seasonal norms.
Another ridge of high pressure will start to build into the region
Sunday with a warming trend. Forecast confidence then drops off
significantly for next week as models and ensembles offer a range
of solutions wrt to the depth, speed, and evolution of the next
deeper trough, resulting in a large range of temps and precip
timing among guidance.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Wednesday Night)
Issued At 1053 PM MDT Tue Oct 14 2025

Widespread fog, drizzle, and low clouds will persist across
western SD through the forecast period with IFR/LIFR conditions.
Low clouds and IFR conditions will slowly creep into NE WY after
06-07z, persisting through the forecast period.

Rain showers are possible across the area overnight, with
additional chances, and a few thunderstorms, Wednesday afternoon
and evening.

&&

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

$$

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