Cactus Flats, South Dakota Weather Forecast Discussion

574
FXUS63 KUNR 120822
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
222 AM MDT Fri Sep 12 2025
.KEY MESSAGES...
- Unsettled weather heading through the weekend
- Above normal temps to begin the weekend with a cooling temps
  after the first of next week.
&&
.DISCUSSION...(Today Through Thursday)
Issued at 220 AM MDT Fri Sep 12 2025
Latest satellite imagery shows 500hpa ridge axis nosing up through
central MN with western CONUS trough continuing to deepen across
the ID/NV areas. SW flow aloft continues to bring ejecting waves
out of the 500hpa trough over the CWA. At the surface, low
pressure is located in SW SD with an inverted sfc trof poking
northeast through central SD and into central ND. All that is left
from earlier convection is some light -shra across northern
Harding and Perkins counties that will lift into ND shortly.
Pcpn chances will remain across the region as impulses continue to
lift northeast through the CWA in SW flow aloft. 700Hpa theta-e
forcing returns to our WY counties and the Black Hills area by 21z
this afternoon, and continues along and north of I-90 through 06z
Saturday. Noted that ensembles are showing probabilities of
getting over 1 of rain by 06z Saturday from 20-30% across much of
this forcing area, which lines up well with PWATS running
150-200% above normal as well. As dry as things have been the past
couple of weeks...flooding isnt a concern, but there could some
locally heavy rain with some of the stronger storms later this
afternoon and into the evening.
As the upper trof approaches the region Saturday and Sunday,
expect widespread cloudiness with Sunday being the cooler and
rainier day of the two. As the 500hpa trough exits the region for
Monday, expect a brief warmup ahead of the next trough that will
move into the central plains for Tuesday and Wednesday. This
should result in cooler temps along with another shot of
precipitation. However, given blocking flow aloft, exact timing
and location remain uncertain.
&&
.AVIATION...(For the 06Z TAFS Through 06Z Friday Night)
Issued At 1142 PM MDT Thu Sep 11 2025
Scattered thunderstorms will affect northwest South Dakota early
this morning...mainly before sunrise. Local MVFR/IFR conditions
are expected in the heavier precipitation. Otherwise VFR
conditions will continue through the forecast period. More
thunderstorms are expected across the area Friday afternoon and
evening.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...Hintz
AVIATION...13

NWS UNR Office Area Forecast Discussion