410
FXUS63 KBIS 080340
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1040 PM CDT Sun Sep 7 2025

.KEY MESSAGES...

- Warming trend to start the week.

- Smoke also makes a return to start the week.

- Chances for showers and thunderstorms return mid to late
  week.

&&

.UPDATE...
Issued at 1040 PM CDT Sun Sep 7 2025

Limited changes needed late this evening. Smoke aloft and mid to
high clouds aloft continue to filter into the region. Made some
minor sky adjustments to account for this increased cloud cover
and increased smoke aloft. Some CAMs have the isolated shower
and thunderstorm activity currently in Montana trying to make
it into western North Dakota late tonight into Monday. Given the
dry air in place there is low probability of this. Matched up
some PoPs along the MT/ND border for now.

UPDATE
Issued at 637 PM CDT Sun Sep 7 2025

Limited updates needed early this evening. Smoke and clouds
aloft are starting to filter into the region and will continue
to do so through tonight. Smoke at the surface is not
anticipated until Monday, and mainly in the southwest and south
central. Made some minor sky adjustments based on current
satellite trends. Otherwise the forecast remains on track.

&&

.DISCUSSION...
Issued at 122 PM CDT Sun Sep 7 2025

This afternoon surface high pressure was situated over the upper
and mid Mississippi River Valley while low pressure was
developing in the lee of the Canadian and Northern Rockies. In
the upper levels, a deep trough was situated over the eastern
U.S. with an upper ridge over the Rockies and another trough
situated over the eastern Pacific. Currently, skies were mostly
clear across much of the region with some high thin clouds over
the northern High Plains and pushing into the western Dakotas.
Areas of smoke, aloft, were also situated over the northern High
Plains. Southerly return flow around the back side of the
surface high was gusting to around 25-30 mph over far western
ND.

It looks to be a quiet night across the forecast area tonight
and milder, with no threat of frost. Some low stratus or patchy
fog is possible in the south central and into the James River
Valley but cams have been backing off on this compared to
earlier in the day. Will leave fog out of the forecast at this
time but will pass along to the evening shift. Smoke will also
begin to move into western ND late tonight. Will utilize latest
HRRR smoke model to depict smoke through the day Monday.

A northern stream shortwave and attendant surface trough will
track into the Northern Plains and southern Canadian Prairie
Provinces, and by mid morning Monday will be situated around
northwest North Dakota. Another wave tracking through the
central Rockies and will help induce warm advection across the
Dakotas through the day Monday, with an area of modest
instability developing over the eastern Dakotas and into western
Minnesota. During the day the aforementioned surface low will
track southeast into south central ND by late afternoon/early
evening, with a trailing cold front dropping southward through
western ND. Forecast soundings from south central into
southeast ND do show modest (GFS) to moderate (NAM) instability
above a slightly capped atmosphere. CAMS do show some
developing reflectivities over central and eastern ND Monday
afternoon but little in the way of QPF. The NAMNest is one CAM
the currently shows some convection fire over central ND and
track into the southeast portion of the state, but most of the
CAMS keep convection south and east of the forecast area. The
HREF does show some low UH track probabilities over the James
River Valley. Currently there is only a general risk of
thunderstorms over the south central into southeast ND Monday.
The risk for strong to severe storms over this area tomorrow is
non-zero, but pretty darn low at this time. Farther west The
weak cold front that pushes through western ND Monday will bring
a wind shift with northwest winds behind the front. Lower
humidities and some breezy afternoon winds from the northwest
can be expected over western ND. At this time fire weather
concerns remain low due to the lack of dry vegetation. This
could begin to change after our recent freezing temperatures in
the west, but not yet.

As we continue through the work week we will see the eastern
Pacific trough move onshore around midweek and slowly tracks
east into the Rockies by the end of the work week. This will
bring chances for showers and some thunderstroms to the forecast
area mid to late week. It will take some time to figure out
exactly how quick this happens and where the upper level low
eventually ends up next weekend (yeah it will take about a week
for the upper low to get here). Until then the NBM is currently
depicting some low to medium chances for showers and
thunderstorms Wednesday and Thursday, with mainly medium chances
Friday and Saturday. Highest chances overall will be over
western North Dakota. Temperatures through the period look to
remain near normal, but NBM ensemble spreads do increase quite
a bit late in the period, signifying the unpredictability of the
upper level regime late in the week.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 637 PM CDT Sun Sep 7 2025

Overall VFR conditions expected through the forecast period.
High clouds will filter into the area tonight, along with
wildfire smoke aloft, and persist through Monday. This smoke
could make it to the surface Monday, mainly in the southwest and
south central. This could impact the KDIK TAF with low VFR to
perhaps MVFR visibilities. Some patchy fog may also be found
tonight into Monday morning, although confidence remains to low
to include in the TAFs at this time. Southerly winds through
this evening will become light tonight into Monday morning, then
may become westerly Monday afternoon.

&&

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

&&

$$

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