Garrison, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

677
FXUS63 KBIS 301137
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
637 AM CDT Fri May 30 2025

.KEY MESSAGES...

- A small chance (20%) of a shower or thunderstorm west and
  central this afternoon and evening, otherwise warm and mainly
  dry conditions expected through the weekend, with widespread
  highs in the 80s this weekend.

- Wildfire smoke will produce hazy skies, but with limited areas
  of smoke at the surface today. Hazy skies will continue this
  weekend, with widespread areas of smoke at the surface
  possible.

- A cold front will bring showers and thunderstorms to the area
  Sunday night through Monday night, with strong to severe
  storms possible Monday afternoon and evening.

- Cooler temperatures in the 60s and 70s are then expected
  through the remainder of the work week with hit and miss
  showers and a few thunderstorms.

&&

.UPDATE...
Issued at 625 AM CDT Fri May 30 2025

Current forecast remains on track.

&&

.DISCUSSION...
Issued at 400 AM CDT Fri May 30 2025

Currently, high pressure was situated over the northern Plains
with clear skies across much of the northern and central Plains.
Temperatures were mainly in the 50s with no indication of any
fog. Back to the west, a cold front was situated over central
Montana. Aloft, an upper level ridge was over eastern Montana,
and a shortwave can be seen along the International Border in
far southern Alberta. This shortwave and associated cold front
will track east today and bring small chances for showers and
possibly a thunderstorms over western and central North Dakota
this afternoon and evening.

Prior to the arrival of this feature, the main forecast issues
today will be high temperatures and the impacts due to wildfire
smoke. Initially today, the smoke should be mostly aloft. The
latest HRRR models shows vertically integrated smoke covering
the forecast area this morning, but diminishing from west to
east today. Given the smoke aloft may dissipate some, will not
adjust forecast highs from NBM guidance attim, which is in the
upper 70s to mid 80s. Surface smoke may increase somewhat this
afternoon and tonight behind the weak cold front, but
concentrations of near surface smoke, in addition to a return of
higher concentrations of smoke aloft, are forecast to drop from
north to south through the forecast area late tonight into
Saturday, and remaining through the day. It`s likely that smoke
will remain in some fashion through the weekend. The latest HRRR
model goes through the day Saturday but would expect smoke to
continue as new model runs come in. As of now, there have been
little if any reductions in visibility, but this may certainly
change later tonight and into the weekend if HRRR model trends
continue.

As mentioned earlier, the cold front may bring some isolated
convection this afternoon into this evening over western and
central North Dakota. Bufkit soundings were not impressive with
generally less than 500 J/KG of CAPE and limited moisture.
However, with decent heating, and the forcing associated with an
upper level jet diving southeast, there may be enough
ingredients to produce a few thunderstorms. Bulk shear is also
weak, so with the weak cape and shear, the threat of anything
severe is quite low. The main hazard would probably be some
locally gusty winds with any storms that may develop.

Highs on Saturday and Sunday should be well into the 80s most
areas and pushing the lower 90s in some areas on Sunday. Whether
or not these highs get knocked down some (due to smoke) remains
to be seen. for now, we`ll be sticking with the given NBM
temperatures.

Sunday night and Monday a northern stream upper level trough and
associated surface cold front tracks through the northern Plains
bringing increasing chances for showers and thunderstorms.
Currently, it looks like Monday afternoon/evening would be the
best chance for strong to severe storms. SPC continues to target
the far southeast CWA for potential severe storms during this
timeframe.

Monday will be a transition day temperatures wise with again in
the 80s to lower 90s over far south central and into the James
River Valley, with 60 degree readings in the northwest. We
remain in the 60s Tuesday then climb into the 70s Wednesday and
Thursday. After Monday we remain within a broad northwest upper
flow through Thursday which should support daily chances for
hit and miss showers and a few thunderstorms.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 625 AM CDT Fri May 30 2025

VFR conditions are expected today with mostly clear but
smoky/hazy sunshine. A cold front will move into western North
Dakota this afternoon, and central ND this evening. Southerly
winds ahead of the front will shift northwest behind the front.
Northwest winds later this afternoon into the early evening may
be gusty to near 25kts at times at KXWA and KDIK. Isolated
showers and possibly a thunderstorm behind the cold front over
western ND this afternoon into early this evening so we included
a VCSH at KXWA and KDIK. Thunder probabilities too low for a
VCTS mention at this time. Precipitation chances diminish as
the front pushes into central ND so did not include a mention of
VCSH at KMOT or KBIS at this time. There is the potential for
smoke to drop south from Canada later tonight and continuing
through Saturday. At this time the uncertainty is too high to
include a reduction in visibility due to smoke, but this is
certainly a possibility later tonight and into Saturday, beyond
the 12Z TAF period.

&&

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

&&

$$

UPDATE...TWH
DISCUSSION...TWH
AVIATION...TWH