983
FXUS63 KBIS 010840
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
340 AM CDT Tue Sep 1 2026

.KEY MESSAGES...

- Isolated showers are possible across the south later today
  through this evening.

- An increased chance for showers and thunderstorms looks to be
  found Wednesday evening through Thursday. Periodic chances for
  showers and thunderstorms may then be found through the
  weekend.

- Temperatures go on a warming trend through the end of the
  week, then cooling somewhat late this weekend into early next
  week.

&&

.DISCUSSION...
Issued at 340 AM CDT Tue Sep 1 2026

Ridge of high pressure will break down slightly today and give
way to a weak upper level wave moving through in southwest flow.
With the lack of temperature advection to the area, temperatures
look to remain near to perhaps slightly below normal today with
highs in the 70s to lower 80s. The mentioned upper level wave
does look to bring some decent vorticity advection this
afternoon through this evening. Hi-res models indicating some
shower activity is possible as a result, mainly along and south
of Interstate 94. There is an abundance of dry air this wave
would have to overcome, and the better moisture plume looks to
stay to our south. Confidence is low with shower activity today,
although hi-res guidance is consistent on placing in some
showers. Thus added slight pops to these southern areas this
afternoon through much of the evening. The chance for
thunderstorms today is fairly low given the lack of instability.
Shower activity then diminishes late this evening with overnight
lows in the 50s. Light winds and high RH recoveries could bring
some patchy fog tonight into Wednesday morning, provided some
clearing of clouds occurs. Brief ridging aloft then moves
through for Wednesday, keeping mainly dry conditions. A switch
to breezy southerly flow at the surface could bring start a
warming trend with highs in the mid 70s to mid 80s. Wednesday
evening through Wednesday night, surface low kicks out of the
northern Rockies and brings a weak warm front across the area.
This could return more broad chances for showers and
thunderstorms across the state. There is a decent amount of
elevated instability with this wave, while the mix and surface
layers have limited instability and strong capping. Shear also
looks low with this wave. Give the later timing of this wave the
severe threat is overall low with only an isolated strong storm
possible. Lows Wednesday night will be warming and generally
near 60. Shower and thunderstorm chances could linger in the
north and east on Thursday as the warm front continues to move
through. The severe weather threat again looks low given the
same reasons previously discussed. Ridging aloft then brings
dry conditions, while the resultant warm sector behind the warm
front continues to warm temperatures in the upper 70s to upper
80s. Mainly dry and mild conditions are then expected for
Thursday night with lows again near 60 degrees.

Friday through the Labor day weekend...ridging aloft will
provide southwest flow at times through the holiday weekend.
High temperatures look to stay above normal, and perhaps in the
lower 90s, through at least Saturday. Sunday onward sees a
cooling trend in forecast temperatures, although spreads remain
large. This is from the uncertainty on the influence of a large
pacific northwest trough, possibly moving inland late this
weekend or early next week. Shower and thunderstorm chances look
limited to start the weekend, although the southwest flow could
bring weak disturbances at times. Increased precipitation
chances may come later in the weekend into early next week
depending on the progression of the upper level trough. Of note
could be some increase monsoonal moisture with this next trough,
possibly providing some localized increased rain totals.
However, this is highly dependent on where this trough tracks
early next week. Lastly, fire weather concerns may be slightly
elevated to end the week due to warm temperatures and some dry
air lingering in the west. RH values look to improve later in
the weekend, helping to limit the fire weather danger.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1240 AM CDT Tue Sep 1 2026

VFR conditions are forecast to prevail through the forecast
period. Light and variable winds across the west and central
will become a southeast wind later Tuesday. Some northern and
eastern portions will see a steady northwest wind become light
and variable later Tuesday. Some mid to high clouds may also be
found at times throughout the forecast period.

&&

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

&&

$$

DISCUSSION...Anglin
AVIATION...Anglin