394
FXUS63 KUNR 151106
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
506 AM MDT Tue Sep 15 2026

.KEY MESSAGES...

- Gusty winds diminish overnight.

- Unsettled temperatures continue this week.

- Multiple weak precipitation chances this week, with the best
  chance this weekend.

&&

.UPDATE...
Issued at 926 PM MDT Mon Sep 14 2026

No big changes to the forecast Monday evening. The gusty winds
from earlier have been slowly diminishing with this pattern
likely to continue overnight.

Northerly winds will swing back to the south/southeast Tuesday at
speeds peaking around 10 to 20 mph in the late afternoon to
evening, wind gusts upwards of 30 mph. Afternoon high
temperatures will be at or below normal for this time year, mainly
in the 70s. Skies will be clear to mostly clear.

Tuesday night is the next chance for passing light rain but
amounts won`t be much, at just a few hundredths of an inch for
those who receive measurable precip.

Unsettled pattern lingers with continued low-end chances for
passing rain and thundershowers.

&&

.DISCUSSION...(This Evening Through Monday)
Issued at 1225 PM MDT Mon Sep 14 2026

Current upper-air analysis and water vapor imagery depict the
surface low over northeast MT/northwest ND and a cold front pushing
southeast across the Dakotas and into NE. Satellite imagery
indicates partly cloudy skies behind the front as it moves out of
the region. Surface observations show temperatures mainly in the
upper 60s and into 70s, with dewpoints in the 50s and 60s. West-
northwesterly winds are gusting up to ~40kts across much of
northwest SD and the plains to the east of the Black Hills and could
reach as high as 50 to 55kts today. A wind advisory is in effect
from 14/17z to 15/03z. These conditions will bring extreme fire
danger to northwest SD, with any fires that start being capable of a
very high to extreme rate of spread. One factor that will help in
the suppression of fire potential today is the precipitation that
fell this morning over portions of northwest SD, with some areas
seeing ~0.5" of rain, though drier portions of the fire weather area
outside the rain-affected zone remain most at risk.

Elsewhere, winds will be breezy behind the frontal passage,
generally gusting 25 to 35kts, and will slowly diminish overnight,
becoming lighter by early morning. Temperatures will stay near
seasonal, with highs mainly in the 70s with parts of southwestern
and south-central SD reaching the 80s. Precipitation will exit the
region over the next few hours, leading to drier conditions for the
rest of the day and into Tuesday.

Looking ahead, temperatures will be a roller coaster as the jet
stream wiggles back and forth over the region, with highs bouncing
between the 70s and 80s in a typical summer-to-fall transition.
Breezy conditions will be common most days, and multiple weak
precipitation chances will pass through, though meaningful rainfall
may be limited. Elevated fire weather conditions will remain a
concern across northeast WY and parts of southwest SD through the
week given the breezy pattern, continued drought conditions, and
limited rainfall. This weekend currently looks like the best shot
at meaningful precipitation as an upper-level disturbance moves
over the region. However, this is several days out and details may
change.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Wednesday Morning)
Issued At 506 AM MDT Tue Sep 15 2026

VFR condtions are expected throughout the forecast period.

&&

.FIRE WEATHER...
Issued At 1225 PM MDT Mon Sep 14 2026

West-northwest winds gusting to 50-55kts across northwest SD today
will drive extreme fire danger, with any fires capable of very
high to extreme spread rates. Morning rainfall (~0.5) over
portions of northwest SD offers some localized suppression, but
drier areas outside that zone remain most at risk. Elevated fire
weather continues into the week for northeast WY and parts of
southwest SD due to breezy winds and continued drought
conditions, however, RH values won`t be at critical level.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

UPDATE...GS
DISCUSSION...Schultz
AVIATION...Wong
FIRE WEATHER...Schultz