073
FXUS63 KBIS 020250
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
950 PM CDT Mon Sep 1 2025

.KEY MESSAGES...

- Isolated to scattered thunderstorms possible tonight and
  Tuesday. A few storms may be strong to severe, mainly
  southeast on Tuesday.

- Cooler weather with highs in the 60s and 70s anticipated mid
  to late week. Overnight lows in the 30s and 40s also forecast.

- Areas of wildfire smoke may also return on Tuesday.

&&

.UPDATE...
Issued at 929 PM CDT Mon Sep 1 2025

Thunderstorms have dissipated across the forecast area. Only a
few lingering showers remain in the north central through west
central. Expect this activity to wane as well over the next
hour. Lingering shower activity could hold on a while longer in
the far north central, but nothing of any significance.

No significant updates planned this evening. There are some
reductions in visibility upstream over central Saskatchewan so
no changes planned with the mention of smoke. There may be some
patchy fog tonight south central into the James River Valley but
probabilities look pretty low and CAMS are not all that
excited. Will monitor but keep it out of the forecast for now.

UPDATE
Issued at 641 PM CDT Mon Sep 1 2025

Isolated thunderstorms continue across portions of western and
central ND within an unstable airmass. A couple of severe storms
have been observed over the southwest portion of the state which
is within an area of better shear. Very little shear remains in
the north so the threat for severe storms is low, but definitely
a few stronger storms and an isolated severe storm can`t be
ruled out in the next hour or so. The strong to severe storms in
the southwest may continue to hold together, but will be moving
into SD in the next 1-2 hours. By this time we will be losing a
lot of the solar heating so we think we`ll see a downtrend in
storm strength for sure by then across the forecast area. No
significant updates other than extending the blanket slight
chance pops through 9 PM.

&&

.DISCUSSION...
Issued at 240 PM CDT Mon Sep 1 2025

Currently, remnants from a stationary mid/upper level low across
the Dakotas/Great Plains continues to generate isolated
showers/thunderstorms this afternoon, mainly across central and
the eastern areas of the state this afternoon. However, other
activity randomly popping up west as well. Enough low level
helicity and strong low level CAPE to result in a chance for a
few funnel clouds southeast, as already reported in LaMoure
county.

We expect most precipitation chances to move east with time
today into this evening as we lose daytime heating, leading to
a mostly clear sky across western and central North Dakota
tonight. However, increasing northerly flow will usher in
wildfire smoke from Canada, so hazy conditions are
expected/possible for later tonight into the day Tuesday across
the area. Low stratus also possible north. In addition, the
chance for northern lights are forecast to push south into the
northern CONUS tonight and somewhat Tue night, but unsure what
if any impact the increasing smoke will have.

Truly the main story for the forecast period (besides the
lingering chances for strong convection today and tomorrow) will
be a refreshing shot of Arctic air later Tuesday into Wednesday
as a strong mid level low surges south across central Canada.
Daytime highs in the 60s to mid 70s and overnight lows in the
30s and 40s are forecast to end the week. Minimal precipitation
chances.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 641 PM CDT Mon Sep 1 2025


Mainly VFR conditions with a light south-southwest wind through
this evening, becoming westerly overnight. Isolated
thunderstorms are possible through around 02 UTC before
diminishing. Any thunderstorm could produce MVFR-IFR cigs and
vsbys and gusty erratic winds. Patchy fog again possible
tonight into Tuesday morning, although confidence is low at this
time. Wildfire smoke is also expected to return to the area
from north to south late tonight into Tuesday. MVFR ceiling are
forecast to drop down from the North as well Tuesday. At this
time limited this to MVFR ceilings at KMOT. Will need to monitor
however.

&&

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

&&

$$

UPDATE...TWH
DISCUSSION...NH
AVIATION...TWH