Winner, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

095
FXUS63 KUNR 052349
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
549 PM MDT Fri Sep 5 2025

.KEY MESSAGES...

- A Frost Advisory has been issued. Please view hazard details at
  weather.gov/unr

- Warming trend will lead to temperatures climbing above seasonal
  normals for much of next week

- Expect dry conditions throughout the weekend

&&

.UPDATE...
Issued at 547 PM MDT Fri Sep 5 2025

Went ahead and expanded the frost adv given guidance trends.
Clear skies, light winds, and very dry air in place should allow
locations on the Plains to drop off quite well later tonight, esp
valleys and drainage areas.

&&

.DISCUSSION...(This Evening Through Friday)
Issued at 118 PM MDT Fri Sep 5 2025

A big upper level low continues to move east across the UP of
Michigan this afternoon. In its wake cool and dry cyclonic flow
persists across much of western SD and eastern Wyoming. Even with
ample sunshine the CAA and stiff NW winds have kept temperatures
on the cooler side with widespread 60s common across the region.
Building heights are expected as the ridge continues to build
across much of the Intermountain west and transition eastward.
This will east the pressure gradient across the area and allow the
breezy conditions to diminish during the evening hours. With drier
air mixing in and allowing for mostly clear to clear skies,
temperatures are progged to fall into the 30s this evening across
a large portion of the region. The sheltered valleys and those
typically cold spots could see temperatures approach freezing.
Confidence is high across northwestern SD to see temperatures drop
and last for several hours and this as prompted for a Frost
Advisory to be issued for these areas. Lower elevations across
the Black Hills and Rapid City eastward will hold on to some
light, downsloping winds that will keep temperatures from turning
too cold but minimum temperatures could still drop to around
38-40F this evening across these areas.

Ridging becomes the dominant weather feature by the latter part of
the weekend and most of next week. Temperatures will rebound as
multiple days under the ridge will lead to a moderating thermal
ridge which will lead to temperatures warming back into the mid to
upper 80s for several days next week with mostly dry conditions.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening)
Issued At 404 PM MDT Fri Sep 5 2025

VFR conditions are expected for the next 24 hours. Gusty northwest
winds will decrease after sunset. Winds will be light and
variable overnight.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Frost Advisory from 2 AM MDT /3 AM CDT/ to 7 AM MDT /8 AM CDT/
     Saturday for SDZ001-002-012>014-030>032-042>044-046-047-073-
     076>078.
WY...Frost Advisory from 2 AM to 7 AM MDT Saturday for WYZ054>056-
     058>060.
&&

$$

UPDATE...JC
DISCUSSION/KEY MESSAGES...Woodward
AVIATION...Wong