Garrison, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

027
FXUS63 KBIS 111435
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
935 AM CDT Wed Jun 11 2025

.KEY MESSAGES...

- Near surface smoke today through Thursday.

- Daily chances for showers and thunderstorms starting today,
  with the greatest chances for precipitation on Thursday (60 to
  80 percent). These chances will continue into next week.

- Near average temperatures today, before cooling off into the
  60s Thursday and Friday, then warming back up into the 70s
  through the weekend and into next week.

&&

.UPDATE...
Issued at 934 AM CDT Wed Jun 11 2025

No major changes were needed for this update as we just slightly
adjusted precipitation chances to better reflect the future
trends of the isolated showers and storms along the South Dakota
border. Otherwise, just blended in the latest observations to
the going forecast.

UPDATE Issued at 625 AM CDT Wed Jun 11 2025

Smoke has continued to settle in across the area this morning,
dropping many locations` visibilities to 2 to 4 miles. Weak
radar returns continue across the northwest, while some more
substantial showers and thunderstorms across eastern Montana
continue to move east towards the border. Overall, not many
changes needed with this update.

&&

.DISCUSSION...
Issued at 253 AM CDT Wed Jun 11 2025

Early this morning, thunderstorms have developed just south of
the border with South Dakota, with some weak radar returns
entering into the northwest. The activity in the south should
stay in South Dakota, though a storm may wander onto the border
for a little bit, resulting in overall low chances for
precipitation there. In the northwest, most of the showers are
very high based above a rather dry environment, resulting in
most of these likely not reaching the ground. A heavier shower
may result in a few sprinkles though, owing to some more low
chances for precipitation. Otherwise, most of the area is
covered in near-surface smoke, with the largest visibility
reductions across the north, generally ranging from 2 to 5
miles. In the south, visibilities are around 8 to 9 miles. This
smoke is expected to stick around for a while, at least through
Thursday morning. Aloft, flow is out of the northwest, with a
weak shortwave approaching, bringing about some low chances (20
to 30 percent) for showers and an isolated thunderstorm across
the west today. While there is some decent instability and shear
just to the west of our border in Montana, the chances of a
storm retaining its strength as it moves into our area is very
low, and the SPC has pulled the Marginal Risk out of our area
now. Highs today will be mostly in the low to mid 70s.

Thursday remains to be the wettest day of the forecast period,
with our highest chances for showers across the west and
central. A more substantial shortwave moving through the flow
will bring showers to the area for much of the day and into the
night, with parts of the southwest and south central possibly
seeing QPF totals approaching half an inch. Totals go down as
you go north, though most of the area is expected to at least
see something, with the exception of the Turtle Mountains. While
moisture and shear will be abundant, temperatures behind the
system`s cold front will dip quite a bit, with areas in the west
possible seeing highs drop below 60 degrees. Most of the area
won`t get above 70 degrees, which will help limit the overall
instability associated with this system. While some thunder may
be possible in the far south, strong to severe storm development
is unlikely at this time.

Temperatures remain cooler on Friday, as a secondary shortwave
lingers across the northern half of the state, with highs
staying largely in the 60s. Precipitation chances decrease
substantially heading into the daytime hours, though some
showers may linger behind the system. A weak ridge is expected
to then build behind this wave Friday night into Saturday, with
an embedded transient wave riding the top of the ridge,
resulting in some medium chances (30 to 50 percent) for showers
overnight Friday into Saturday morning. Thunderstorms are
unlikely with this wave due to the timing. From Saturday
onwards, flow aloft becomes mostly zonal, along with enhanced
surface moisture returns, resulting in warming temperatures,
near daily chances for showers and thunderstorms, and increased
(but still low) probabilities for strong to severe storm
development, with the overall temperature being one of the main
limiting factors. NBM spreads in temperature beyond this weekend
still remain somewhat large, though overall, highs look to
stabilize back into the 70s and lower 80s by the middle of next
week.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 625 AM CDT Wed Jun 11 2025

Near surface smoke has reduced visibilities across the entire
area, with IFR visibilities being reported in the north and
west, including KMOT, KXWA, and KDIK. MVFR visibilities are
present in the south central and James River Valley, impacting
KBIS and KJMS. These visibility values could improve and decline
as the day goes on as the smoke moves and settles across
different locations. In general, slight improvement in
visibility is likely towards the end of the TAF period, though
smoke will remain across the entire area. Otherwise, low chances
in showers are possible in the west, with breezy southeasterly
winds expected in the southwest, with sustained speeds 15 to 20
kts and gusts up to 25 kts. Winds will then decrease in speed
towards the end of the TAF period.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...ZH
DISCUSSION...Besson
AVIATION...Besson