040
FXUS63 KBIS 301148
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
648 AM CDT Sat Aug 30 2025

.KEY MESSAGES...

- Patchy to areas of fog, dense at times, possible across much
  of North Dakota this morning.

- Cooler temperatures in the 70s expected across the south
  today, with 80s lingering in the north.

- Near seasonable high temperatures in the mid 70s to mid 80s
  return Sunday through Labor Day, with lows generally in the
  50s. Cooler temperatures possible during the middle of next
  week.

- Isolated to scattered showers and thunderstorms possible
  through Sunday, mainly south, shifting to the east on Labor
  Day. The probability for severe weather is very low.

&&

.UPDATE...
Issued at 648 AM CDT Sat Aug 30 2025

Fog starting to be reported across much of North Dakota early
this morning. Some sites are report visibility as low as a
quarter mile. Webcams still showing the more dense fog to be
isolated to scattered. Given this coverage uncertainty have
issued an SPS to account for this fog this morning. Motorists
should still drive with caution as areas with fog could see a
quarter mile or less through the mid morning hours. Similar
setup is found tonight, thus placed at least patchy fog mention
in the forecast for tonight into Sunday morning. Otherwise upper
low continues to bring some shower activity in the south. Made
minor PoP adjustments to account for these ongoing showers. SPC
has broad general risk for thunderstorms later today into this
evening. Made some slight pop adjustment to include slight
chances for thunderstorms further north today, yet still south
of Highway 2.

&&

.DISCUSSION...
Issued at 425 AM CDT Sat Aug 30 2025

Weak surface flow combined with high RH could bring widespread
fog this morning. Highest confidence would be for areas south of
Highway 2, although much of the state could see at least patchy
fog. Confidence and coverage is not quite high enough for an
advisory at this time, although will continue to monitor
observations for any potential fog product. Upper low will
continue to slowly move across the region today. This will
continue to bring chances for showers and thunderstorms to the
southern half of the state today. North of this will see enough
instability this afternoon for a few isolated thunderstorms,
although confidence in thunderstorm chances decreases closer to
the international border given a surface high in Canada. With a
lack of shear, the severe weather threat is low today. Any
thunderstorm that does develop could be slow moving and perhaps
produce some heavy rain. Cold air funnels were also observed
yesterday closer to the upper low in South Dakota. This could
happen again today across the region given similar conditions.
High temperatures will be cooler in the south and generally in
the 70s, while remain warm and in the 80s across the north.
Upper low continues to linger across the areas tonight, and
could linger at least some shower chances in the southwest and
south central. Humidity values will again be high, while light
winds are also forecast. Fog could return, although cloudy skies
may limit this potential. Look for lows tonight mainly in the
50s. Upper low looks to push south on Sunday, although
lingering moisture and weak instability could still provide a
few showers in southern and western portions. South wind will
warm temperatures slightly and back into the mid 70s to mid 80s.
Fog may then return again Sunday night into Monday morning,
although a steady south wind along with some cloud cover may
limit this. Shower activity looks to diminish somewhat Sunday
night, with lows in the 50s remaining. Labor Day, a weak short
wave looks to move across the state and return chances for
showers and thunderstorm, mainly in central and eastern
portions. With continues warm temperatures in the mid 70s to mid
80s, instability may be slightly increased. This wave could also
bring some increased, yet still low, shear. Thus an isolated
stronger storm is possible Monday, although the chance for
severe weather remains low. Shower and thunderstorm chances may
linger through the night Monday night, mainly in the north and
east. Look for lows to continue in the 50s.

Cold front still forecast to come through sometime Tuesday.
Current timing has this front moving through Tuesday morning,
bringing some showers and thunderstorm chances. If this front
delays to later in the day then perhaps an isolated stronger
storm is possible. Breezy northerly winds may be found behind
this front on Tuesday, with temperatures also cooling into the
60s and 70s. Tuesday night could see some lingering showers and
thunderstorms in the south. Colder overnight lows in the upper
30s to upper 40s are forecast. A post frontal day then sets up
for Wednesday with cooler temperatures in the 60s. A steady
northerly wind may also be found, although the breezier winds
are forecast for eastern North Dakota. Surface high moving in
should limit precipitation chances on Wednesday. Cool overnight
lows in the 40s, with perhaps some 30s are then possible through
the end of the work week. Building ridge to our west with a
broad surface high in the region should also limit the chances
for precipitation through the end of next week. Temperature
spreads remain large for late next week, although generally show
a warming trend. NBM currently has forecast highs warming back
into the 70s. If the large western ridge moves further inland
these temperatures could be warmer. Lower humidity values could
also be found during the day with this more dry pattern. Winds
could stay northwest through the end of the week, although
strong winds are currently not expected given low ECMWF EFI
values.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 648 AM CDT Sat Aug 30 2025

Patchy to areas of fog is bringing IFR to LIFR conditions
this morning across much of North Dakota. Include fog mention
in the KDIK to KBIS to KJMS TAFs through the mid to late morning
hours, with at least patchy fog possible elsewhere yet not high
enough confidence to include in the remaining TAFs. Once fog
diminishes later this morning, the rest of today sees lingering
clouds and VFR to perhaps some MVFR ceilings. Shower and
thunderstorm chances may continue across southern ND and perhaps
into central ND through much of the forecast period. Confidence
was only high enough to include PROB30 precipitation chances in
the KDIK TAF. Light and variable winds this morning will become
a light south southeast wind later today through tonight. At
least patchy fog may again return tonight into Sunday morning.
Confidence was not high enough to include fog mention in the
late period of the TAFs, although did bring some lower FEW to
SCT clouds to a few sites with higher chances for fog
development.

&&

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

&&

$$

UPDATE...Anglin
DISCUSSION...Anglin
AVIATION...Anglin