305
FXUS63 KBIS 291728
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1228 PM CDT Sat Aug 29 2026

.KEY MESSAGES...

- Isolated severe thunderstorms are possible today through
  tonight. Another round of isolated severe thunderstorms
  possible Sunday through Sunday evening.

- Main hazards with any severe thunderstorm this weekend will be
  large hail, damaging winds, and localized heavy rainfall.
  There is a conditional risk for an isolated tornado threat on
  Sunday.

- Near to slightly above average temperatures will persist
  through late next week.

- Breezy to windy conditions to be found Monday. This combined
  with lower humidity values may bring near critical to critical
  fire weather conditions especially to areas south and west of
  the Missouri River.

&&

.UPDATE...
Issued at 1227 PM CDT Sat Aug 29 2026

Some light returns have been noted on radar across western North
Dakota. This is likely due to some modest ascent ahead of a subtle
shortwave trough forecast to arrive later today. So far, it doesn`t
appear as through rain is making it to the surface, but a few
isolated sprinkles cannot be ruled out before isolated to scattered
thunderstorm development occurs later this evening into tonight.

&&

.DISCUSSION...
Issued at 405 AM CDT Sat Aug 29 2026

The threat for severe weather this morning seems to be
diminished as the low level jet has set up east of the CWA. A
stalled warm front will linger across the state today keeping
temperatures mild and mainly in the 80s. With capping in place
and limited lift, mainly dry conditions will also be found
through much of the day. Later today through tonight, a weak
wave may interact with the surface low bringing chances for
showers and thunderstorms. SPC has a broad area of Marginal Risk
to account for the severe weather threat today. Instability
remains decent with modest shear also in place. Thus any storms
that can develop could be severe. An expected multi cluster
storm mode will limit the severe potential today with hail to
the size of ping pong balls and wind gusts near 60 mph. Elevated
storms could perhaps produce slightly higher wind gusts, while
any storm that rotates could produce slightly larger hail size.
The tornado threat looks low today as hodographs are not quite
favorable for low level rotation. Humid conditions may be found
today, with dewpoints in the 60s to lower 70s. Thus any
thunderstorm that can develop may bring localized heavy rain
fall. Isolated thunderstorms could linger through the night,
with enough elevated instability and shear to perhaps produce a
few stronger storms. Lows tonight will generally be near 60
degrees. If storms and clouds can clear out, then some fog is
possible tonight into Sunday morning, especially in the higher
dewpoint areas across the east. Surface low builds slightly
northward Sunday, while the weak ridging aloft moves eastward.
Increased southerly flow could be found as a result bringing
another mild and humid day. A stacked upper low then looks to
push a cold front across the state later in the day Sunday
through Sunday night. This could be the focus for another round
of at least isolated severe thunderstorms. Modest instability
and shear look again to be found for Sunday. There may be better
lift Sunday with the surface low nudging north, lingering warm
front, and cold front eventually moving though. This increased
lift could be some increased hazards of hail to golf ball size
and winds to 70 mph. There is also a conditional tornado threat
as well as storm mode may be discrete to start before going
linear. Hodographs would support increased SRH during this brief
window, with lower LCLs given the higher dewpoints. This threat
is again conditional on discrete cells forming, although both
SPC and CSU-MLP mention some sort of a tornado threat thus will
include in messaging for Sunday. Uncertainty still remains on
timing and overall confidence in these stronger storms forming.
Morning convection or any delay to the cold front could inhibit
these stronger storms. SPC has a broad Marginal Risk for Sunday
as a result. Localized heavy rain will remain possible for
Sunday given the continued high dewpoints. Thunderstorms will
quickly move east Sunday night, with lows cooling into the upper
40s to upper 50s.

Post frontal and mainly dry day still looks to be found for
Monday. NBM wind forecast remains high with at least advisory
level winds in the north. This stacked low is forecast to have
some strong 850 winds with some modest pressure rises. Cold air
advection may be limited for Monday, but afternoon mixing may be
enough to bring down these stronger winds. Currently, areas
along and north of Highway 2 look to be the main areas of
concern for the stronger winds. Meanwhile, dry conditions on
Monday combined with these stronger winds could bring near
critical to critical fire weather concerns especially south and
west of the Missouri River. Wetting rains this weekend may help
improve this threat, although are highly thunderstorm dependent.
Highs Monday cool into the 70s north to near 80 south. Winds
diminish Monday night, with lows in the mid 40s to mid 50s.
Tuesday through late next week, a return to southwest flow will
return near to slightly above normal temperatures. Weak
disturbances in this southwest flow will also continue near
daily chances for showers and thunderstorms. Some lower RH
values may be found at times next week, which could lead to some
increased fire weather concerns on any breezier days that set
up. Of note are some larger temperature spreads late next week.
This is likely due to some uncertainty of the inland progression
of the next large upper level low in the Pacific NW. A further
east progression could cool temperatures, while any delay in
this low could continue above normal temperatures. Current
forecast leans towards the warmer solution, yet could be a
slight bias given recent warmer weather and may be worth
monitoring how this trends in the coming days.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1227 PM CDT Sat Aug 29 2026

A light and variable surface flow to begin the 18Z TAF period
will become easterly across western and central ND this
afternoon. VFR mid and high level clouds are expected today into
early this evening and a scattered sprinkle or brief shower can
not be completely ruled out, but most will remain dry. Isolated
to scattered showers and a few thunderstorms are possible
tonight and included a PROB30 at all sites. Confidence in where
and when any convection would occur is currently too low for
anything more than a PROB30. Late tonight into Sunday morning
low stratus and fog is possible but again, too uncertain to
include any widespread reductions to VSBY at this time.

&&

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

&&

$$

UPDATE...JC
DISCUSSION...Anglin
AVIATION...TWH