Oglala, South Dakota Weather Forecast Discussion

057
FXUS63 KUNR 081946
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
146 PM MDT Mon Sep 8 2025
.KEY MESSAGES...
- Mostly dry and hot conditions until Wednesday.
- Precipitation chances increase towards the end of the week.
&&
.DISCUSSION...(This Evening Through Monday)
Issued at 121 PM MDT Mon Sep 8 2025
Current upper air models show upper ridge over the Rockies, with
weak shortwave over western to central South Dakota, and west
northwest flow over the forecast area this afternoon. Surface
analysis also depicts a surface trough over central SD, while high
pressure sits over western Wyoming. Current radar shows a few
high based showers/storms over the central and southern foothills,
and some elevated showers in far southeastern MT. Temperatures
currently sit in the 80s over most of the forecast area, with a
few areas right around 90.
Isolated showers/storms will continue this afternoon into the
early evening as shortwave treks across the state, though most
places can expect to remain dry today. Upper ridge slides
eastward into the northern and central plains Tuesday through
early Wednesday as a result of upper trough digging into the PAC
NW. Weak energy under the ridge once again tries to fire up a few
showers/storms during the day Tuesday into early Wednesday
morning, mainly over the Black Hills to southwestern and
south central SD, though most places can expect to remain dry
again.
Later Wednesday upper ridge axis beings to slide east of the FA
as the upper trough digs into the southwest CONUS, setting up
southwest flow over the region. Shortwave energy ejecting up into
the region the latter half of Wednesday will bring another chance
for isolated shower/storms.
Closed upper low develops at the base of the western trough, 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.
&&
.AVIATION...(For the 18Z TAFS Through 18Z Tuesday)
Issued At 143 PM MDT Mon Sep 8 2025
Isolated high-based thunderstorms are possible through 06Z that
may produce brief gusty winds. Otherwise, VFR conditions are
expected.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...Dye
AVIATION...Smith

NWS UNR Office Area Forecast Discussion