Rapid Valley, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

220
FXUS63 KUNR 142335
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
435 PM MST Wed Jan 14 2026

.KEY MESSAGES...

- High winds Thursday afternoon into Friday with widespread gusts
  of 60 to 70+ mph. Highest gusts expected across northwestern SD.

- Light snow over the northern Black Hills Friday morning. Minor
  accumulations but the high winds could cause areas of blowing
  snow and hazardous travel conditions.

- Gusty northwest winds across the western SD plains on Sunday.

&&

.DISCUSSION...(This Evening Through Wednesday)
Issued at 151 PM MST Wed Jan 14 2026

Upper level analysis has a ridge over the western CONUS with a
trough extending down the Mississippi River Valley. The Northern
Plains remains in northwest flow, centered between these two
features. At the surface, a stationary front extends from a low in
British Columbia through western North Dakota into central South
Dakota and central Nebraska and a cold front is just off-shore in
the Pacific Northwest. Current surface temperatures range from
the mid 30s across south central South Dakota to the lower 50s
across portions of northeastern Wyoming and the eastern foothills.

The main forecast concern is the high wind event Thursday and
Friday. The stationary front across central South Dakota will slowly
push westward tonight as high pressure deepens over the Central
Plains. At the same time, the cold front over the Pacific Northwest
will race across the northern Rockies into the Northern Plains by
Thursday morning, crossing through the forecast area on Thursday.
Northwest winds will ramp up behind the cold front with gusts of 55
to 60 mph likely by the mid afternoon and evening hours. A
secondary cold front drops through the area on Friday,
intensifying the gradient even further, with the strongest winds
occurring Friday morning. Models indicate 55-70 kt winds within
the boundary layer mixing down to the surface. Additionally, the
14/00z ECWMF EFI (Extreme Forecast Index) is showing wind gusts in
the 90-95th percentile over much of the CWA with the Shift of
Tails of 1-2, and the NAEFS Mean Wind Speed and Climatological
Percentile at 99.5-MAX for wind speed, indicating the potential
for a higher end wind event. At this time the signals aren`t as
strong as it was for the December 17-18 historic wind event, but
there is high confidence in strong northwest winds Thursday
afternoon into Friday. Widespread gusts of 60+ mph will be common,
with higher gusts of 75+ mph possible across northwestern South
Dakota. Winds will gradually diminish Friday night and through the
day on Saturday, but another dry cold front will result in strong
northwest winds across the western South Dakota Plains on Sunday.

The secondary concern is snowfall potential. At this time, amounts
appear to be light as most of the moisture will be east of the
forecast area, but combined with the wind, the potential exists for
visibility reductions with falling snow. Upslope light snow develops
Thursday afternoon over the northern Black Hills and continues into
Friday morning. The highest Froude numbers and relative humidity
occur Thursday night and Friday morning. Overall accumulations look
to be around an inch or so, with the HREF indicating a 70 percent
chance of an inch or greater and less than a 10 percent chance of
three inches of snow. Additionally, steep lapse rates and surface
based lift associated with the secondary cold front on Friday
could lead to the development of snow squalls or at the very least
a band of light snow over the far eastern portion of the forecast
area. The timing of these features will be key, thus hi-res
models closer to the event will provide more clarity on location.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening)
Issued At 433 PM MST Wed Jan 14 2026

MVFR ceilings remain across central SD. Cigs will improve this
evening. West of this boundary, VFR conditions will prevail.
Increasing winds overnight with low-level wind shear possible
after 06Z in the west.

&&

.FIRE WEATHER...
Issued At 151 PM MST Wed Jan 14 2026

Very windy conditions are expected Thursday and Friday along with
colder temperatures. Northwest winds will increase Thursday during
the day and will continue into the weekend. The strongest winds will
be Thursday night through Friday morning when gusts will exceed 60
mph. Wind gusts over 75 mph will be possible on the South Dakota
Plains from far northwestern South Dakota to locations just east of
the Black Hills. Winds will diminish Friday night across
northeastern Wyoming and the Black Hills and through the day on
Saturday across the western South Dakota Plains. However, winds will
increase again on Sunday, with gusts of 50+ mph possible. Minimum
relative humidity will range from 25 to 35 percent across
southwestern South Dakota and along the eastern slopes of the Black
Hills to 35 to 50 percent elsewhere. However, the strong winds
combined with cured fuels and the lack of wetting precipitation will
support widespread elevated to near critical fire weather conditions
and extreme Grassland Fire Danger, especially across the western
South Dakota plains.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...High Wind Watch from Thursday morning through Friday afternoon
     for SDZ001-002-012>014-025-026-031-032-043-072-073-078.
     High Wind Watch from Thursday afternoon through Friday afternoon
     for SDZ024-028.
     High Wind Watch from Thursday evening through Friday afternoon
     for SDZ027-029-030-041-042-044-046-047-049-074>077.
WY...High Wind Watch from Thursday morning through Friday afternoon
     for WYZ060.
     High Wind Watch from Thursday afternoon through Friday afternoon
     for WYZ054>059.
&&

$$

DISCUSSION/KEY MESSAGES...13
AVIATION...JC
FIRE WEATHER...13