951
FXUS63 KBIS 021401
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
901 AM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Areas of smoke across central North Dakota will persist
  through tonight, diminishing from west to east, limiting
  visibility and impacting air quality at times.

- Below average temperatures are expected to continue through
  the rest of the weekend, with highs mainly in the lower 70s
  to lower 80s and lows in the lower 50s to lower 60s.

- Periodic chances for showers and thunderstorms (20 to 60
  percent) remain in the forecast through the rest of the
  weekend and into early next week.

&&

.UPDATE...
Issued at 901 AM CDT Sat Aug 2 2025

Patchy fog is dissipating, though may linger a bit longer.
Regardless, areas of smoke will maintain reduced visibility
across most of the state through the day today. All in all, the
forecast remains on track.

UPDATE
Issued at 631 AM CDT Sat Aug 2 2025

Some fog has developed across portions of the southwest as a few
of the CAMs had hinted at earlier. It has been a little bit of a
challenge to determine what is patchy fog and what is smoke but
traffic cams and surface observations are pretty clear that we
are seeing some fog over the southwest as Dickinson airport has
dipped as low as a quarter mile in the past hour. Precipitation
mainly remains in South Dakota but we could be seeing some
sprinkles along the border in Sioux county. Other than adding
mention of fog across portions of the west and central, no major
changes were needed for this update.

&&

.DISCUSSION...
Issued at 334 AM CDT Sat Aug 2 2025

Weak ridging and stagnant flow aloft will keep most of western
and central dry through the day. A remnant MCV continues to move
east across central South Dakota with widespread cloud cover
extending into southwest and south central North Dakota. A few
showers will also remain possible across the far southwest and
far south central through the morning as this impulse moves
through the region. Some CAMs reinvigorate convection
associated with the MCV over the James River Valley in the
afternoon and some CAMs keep the convection well into South
Dakota. Areas of near surface smoke will also persist through at
least tonight across portions of central North Dakota. Smoke
aloft is likely to remain prevalent as well considering the
stagnant flow.

The upper level ridge will break down a bit tonight, leaving
most of our area in a split flow regime aloft. A weak wave will
bring some low to medium chances (20 to 40 percent) for showers
and storms to the west by late afternoon/early evening,
spreading into the central overnight. The best chances will
generally be across the west and south. If storms can develop
across the southwest later today, they will have access to a
narrow axis of around 1000 to 2000 J/kg MLCAPE but only around
20 to 25 knots of deep layer shear. So, a strong pulse storm or
two will be possible but severe weather is generally not
expected. That being said, PWATs will be high for this time of
year and storm motions will be slow, so locally heavy rainfall
will be possible.

The outlook for showers and storms on Sunday will be similar to
today but maybe a bit more widespread and further into central
North Dakota, especially late in the day. There should be
sufficient instability for a few stronger storms but shear
remains weak. Slow storm motions and high PWATS will mean the
potential for more locally heavy rainfall with the best chances
(30 to 50 percent) late in the afternoon and in the evening.

Ridging tries to build back in on Monday but low chances (20 to
30 percent) for showers and thunderstorms will persist as
several weak waves move through the messy and weak pattern
aloft. A better chance (30 to 60 percent) for showers and
storms may come on Tuesday (especially late in the day and into
the evening) as the ridge axis deamplifies and moves east,
leaving our area in mean zonal aloft through the rest of the
week. Daily low to medium precipitation chances (20 to 40
percent) will continue through at least Friday.

Below average temperatures will remain in the forecast through
the rest of the weekend with highs in the lower 70s to lower 80s
and lows in the lower 50s to lower 60s. The NBM then forecasts
a gradual warming trend through next week with some highs in
the mid 80s returning to the southwest by Monday. Widespread
highs in the mid to upper 80s could then return to western and
central North Dakota mid to late week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 631 AM CDT Sat Aug 2 2025

Some fog has developed this morning across the southwest part of
the state, most notably impacting KDIK with LIFR visibilities as
low as a quarter mile over the past hour. Elsewhere, we are
seeing widespread MVFR or low VFR visibility categories due to
smoke from distant wildfires. Smoke could stick around through
the 12z TAF period but fog should start to lift mid to late
morning. Guidance also suggests a window for some MVFR stratus
west and south central this morning but it has yet to really
materialize so some uncertainty remains. Finally, there will be
some low chances of showers and thunderstorms this evening with
the best chances west and south. Will advertise the potential
with PROB30 groups at KXWA, KDIK, and KJMS.

&&

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

&&

$$

UPDATE...Telken
DISCUSSION...ZH
AVIATION...ZH