Philip, South Dakota Weather Forecast Discussion

210
FXUS63 KUNR 172037
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
237 PM MDT Wed Sep 17 2025
.KEY MESSAGES...
-Widespread showers and a few thunderstorms will continue through
 tonight before gradually ending Thursday into Thursday night
-Total rainfall amounts of one quarter inch to two inches are
 expected, with the highest amounts across western and central SD
-Dry and warmer weather this weekend and most of next week
&&
.DISCUSSION...(This Evening Through Wednesday)
Issued at 152 PM MDT Wed Sep 17 2025
Radar imagery this afternoon shows widespread rain and a few
embedded thunderstorms across western South Dakota, with more
scattered showers into northeast Wyoming. This activity is
associated with an upper level low centered near KVTN, and a
deepening 1016mb surface low near Draper. The widespread rain
will continue to wrap around the low into this evening before
gradually shifting eastward overnight into Thursday as the
surface low moves off to the east per 12Z guidance. Rain chances
near 100 percent today across western SD will subsequently
diminish down to just slight/low chances by Thursday afternoon
before ending across the cwa by Thursday night into early Friday.
Latest QPF totals for this event indicate around one half inch or
less of rainfall across northeast Wyoming, with one half inch
along the WY/SD border to near 2 inches along the eastern cwa
border. No flooding impacts are anticipated due to the long
duration of this beneficial light to moderate rain event. Of note,
north to northeast winds are anticipated to increase considerably
late today into tonight over the western and central SD plains as
the surface low deepens to around 1011mb per CAMs, creating a
5-6mb pressure gradient between KRAP and KICR. This should allow
for occasional north to northeast wind gusts reaching the 30-40
mph range in our eastern half tonight before subsiding Thursday
morning.
The upper low will linger across SD through Friday before finally
getting kicked off to the east as a stronger H5 shortwave shifts
southeast out of southern Canada by Saturday. Dry northwest flow
will bring a dry and warmer weekend for the region with highs
warming back into the 70s and 80s for Saturday and Sunday. The
forecast for next week is now more uncertain as the 12Z GFS/ECMWF
show yet another upper low taking shape across the northern
Rockies and moving into the northern Plains early next week,
which could potentially bring more rain and thunderstorms to the
forecast area Monday and Tuesday. Due to the uncertainty in the
overall pattern and the previously dry forecasts, precip chances
will remain low to negligible for early next week, but may need
to be bumped up in the coming days. Regardless, the long range
pattern continues to look quite active for the northern Plains as
a large upper trough takes hold over the western CONUS.
&&
.AVIATION...(For the 18Z TAFS Through 18Z Thursday)
Issued At 1114 AM MDT Wed Sep 17 2025
A low pressure system will bring deteriorating flight conditions
across much of the region today. MVFR/IFR conditions expected to
develop across most of western SD with local LIFR around the Black
Hills by late afternoon/early evening in rain and isolated
thunderstorms. Areas MVFR CIGS will slide into northeastern WY at
times as precipitation rotates through. Breezy north winds will
continue through Thursday across western SD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...Shamburger
AVIATION...Helgeson

NWS UNR Office Area Forecast Discussion