Cedar Canyon, South Dakota Weather Forecast Discussion

281
FXUS63 KUNR 080939
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
339 AM MDT Mon Sep 8 2025
.KEY MESSAGES...
- Mostly dry and hot conditions expected until mid-week.
- Precipitation chances increase towards the end of the week.
&&
.DISCUSSION...(Today Through Sunday)
Issued at 313 AM MDT Mon Sep 8 2025
09Z upper level analysis has broad ridge across the western CONUS
with weak shortwave energy topping the ridge. This is producing
some light radar returns, most of which are likely not getting any
precipitation to the ground. At the surface, weak stationary
boundary runs from northwest to southeast across the SD plains,
with slightly dryer and warmer air on the western side of the
boundary. Temperatures across the forecast area at 3 AM are in the
50s and 60s, with light and variable winds.
Upper ridge will build across the Northern Plains today through
Wednesday, with mostly dry conditions and above average
temperatures. Weak energy under the ridge may produce and isolated
afternoon/evening shower or storm each day, but the majority of
the forecast area will remain dry through Wednesday. Smoke from
the Canadian wildfires will filter into the area for the next
couple of days.
As the upper ridge axis shifts just east of the forecast area late
Wednesday, precipitation chances begin to increase as the area
falls under increasing southwest upper flow. Isolated to scattered
showers and thunderstorms will be possible Wednesday afternoon
and evening, and again Thursday afternoon and evening.
Temperatures remain above average.
Closed upper low develops at the base of the western trof, and
ejects into the Northern Rockies Friday into the weekend. This
results in much better chances for widespread showers and
thunderstorms across the area, especially from the Black Hills
area and west. With the increase in cloud cover and precip,
temperatures will be cooler for the end of the week. High
temperatures will only be in the 60s and 70s by Sunday.
Weak ridging returns to the area early next week, with precip
chances considerably less than over the weekend.
&&
.AVIATION...(For the 06Z TAFS Through 06Z Monday Night)
Issued At 1048 PM MDT Sun Sep 7 2025
VFR conditions are expected through the TAF period. Light and
variable winds overnight will become gusty around 18 kts in the
afternoon. There is a possibility of showers near KRAP tomorrow
afternoon, however chances are too low to mention in the TAF at
this time.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...15
AVIATION...Pettett

NWS UNR Office Area Forecast Discussion