375
FXUS63 KBIS 091004
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
504 AM CDT Sun Aug 9 2026

.KEY MESSAGES...

- Low to medium chances (20 to 40 percent) for thunderstorms
  late this afternoon into this evening. Some may become severe
  over western and south central North Dakota.

- Daily chances for showers and thunderstorms continue through
  the upcoming work week.

- Near to a bit below average temperatures through the first
  part of the week, then a cooling trend for the later part of
  the week.

&&

.DISCUSSION...
Issued at 326 AM CDT Sun Aug 9 2026

Current surface analysis places low over northeast
Colorado/western Nebraska with inverted trough stretching
through central South Dakota into south central North Dakota,
while high remains over Alberta into Saskatchewan. Upper level
analysis places broad high over the southwestern CONUS with
modest ridging to the north, while low remains over northeast
Manitoba/northern Ontario. Over our area, convection remains to
the south and east of the James River Valley ahead of the
aforementioned surface trough.

For today, quiet weather starts the day as aforementioned
inverted trough pushes off to the east. As we get into the
afternoon and evening hours, another surface low deepens and
pushes through northern Wyoming into southwest South Dakota and
western Wyoming, while an inverted trough pushes into northwest
South Dakota and western North Dakota. In the meantime, a pair
of modest short waves slide through west/northwest flow into our
area. This will bring the next chances for showers/thunderstorms
to western and central North Dakota late today into tonight. In
the meantime, elevated deep layer shear is noted during this
period, with 0-6km values around 45-55kts. The question is how
much moisture can be advected in ahead of the inverted trough,
and thus how elevated the instability may be. With that said,
given the strong shear and the elements present to produce
convection, the severe threat will be present going through the
evening.

West-northwest flow pattern remains active our our area through
mid-week bringing a daily chance for showers and thunderstorms,
with clusters suggesting an upper flow shift to more westerly
or even a bit southwesterly as we get later in the week, which
would continue precipitation chances. Temperatures remain near
to a bit below average through mid-week, cooling below average
for later in the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 102 AM CDT Sun Aug 9 2026

Isolated thunderstorms remain possible over far south central
North Dakota into the James River Valley overnight. Later Sunday
afternoon and Sunday evening, isolated to scattered
thunderstorm chances spread west to east over western and
central North Dakota. In addition, wildfire smoke aloft will
occasionally reach the surface, possibly bringing brief periods
of MVFR visibility.

&&

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

&&

$$

DISCUSSION...JJS
AVIATION...JJS