418
FXUS63 KBIS 040209
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
909 PM CDT Wed Sep 3 2025

.KEY MESSAGES...

- Areas of smoke continue across parts of the west and south
  through this evening.

- A strong cold front will pass through on Thursday, with wind
  gusts up to 55 mph expected.

- Areas of frost are likely early Saturday morning across parts
  of western North Dakota.

&&

.UPDATE...
Issued at 907 PM CDT Wed Sep 3 2025

There are no major changes to the forecast for tonight.
Increasing mid/upper level clouds initially followed by lower
level clouds and chances for precipitation north later tonight
into Thursday morning.

UPDATE
Issued at 641 PM CDT Wed Sep 3 2025

Overall the forecast remains in good shape this evening. Made
some tweaks to hourly weather elements, along with SKY cover,
based on latest observations and trends. Still expect low level
clouds and chances for precipitation to move into the north late
tonight as a secondary cold front/mid level wave pushes south
from Canada.

&&

.DISCUSSION...
Issued at 249 PM CDT Wed Sep 3 2025

This afternoon, an upper low was starting to deepen over the
northern Great Lakes region, with stout cyclonic flow across North
Dakota. Surface high pressure extended across parts of
Saskatchewan and Manitoba into north central North Dakota.
Near-surface smoke has been persistent through the day across
parts of the west and south, although visibilities are generally
around 5 miles and above. It feels like quite a chilly for
early September, with modest cloud cover, breezy north winds,
and afternoon highs in the mid 50s to mid 60s.

While the main low remains nearly stationary, a secondary trough
pushes south on Thursday, bringing a cold front with very strong
winds and chances for showers and a few thunderstorms. The
strongest bubble of pressure rises and cold air advection moves
through western and south central North Dakota during the day
Thursday, with winds quickly increasing after sunrise as the
front drops south. Forecast soundings are broadly in consensus
of around 50 knots at the top of a shallow mixed-layer, so will
increase wording to be sustained winds around 35 mph with gusts up
to 55 mph. We did go ahead and issue a Wind Advisory for
Thursday for almost all of the forecast area, with the exception
of Bottineau, Rolette, and Pierce Counties. Although it is certainly
possible that we have isolated, occasional gusts hitting the
High Wind Warning criteria of 58 mph, at this point there is not
enough confidence for anything higher than a Wind Advisory.
Later shifts can re-evaluate, especially if upstream
observations show higher wind gusts than forecast. As the
surface low moves through, precipitation chances increase, with
medium to high probabilities across the north central and east.
Instability is forecast to be low, but can`t rule out a few
rumbles of thunder. The rain showers could help mix down some
stronger wind gusts as well, although that will be lower
predictability and erratic. Highs on Thursday range from around
50 degrees in the Turtle Mountains area to the lower 70s
southwest.

Friday will be quiet and cooler behind the cold front, with
still a slight northwest breeze and highs in the mid 50s to
lower 60s. Friday night into Saturday morning, there is concern for
areas of frost across much of western and parts of central North
Dakota, with well below average temperatures continuing to filter
into the region from a polar continental air mass. The location
of the surface high expanding into the area might be a little
too far to the northwest to fully maximize the overnight cooling,
but deterministic NBM is already painting lower to mid 30s across
almost the entire forecast area, with the exception of the eastern
James River Valley. Both the northwest and our cold corridor
from Hettinger to Beulah/Hazen have a medium probability of
overnight lows reaching the 32 F threshold.

Saturday should be a quite pleasant although seasonably cool day, as
the surface high begins to slide across the Dakotas, leading to
mostly sunny skies and relatively light winds. Highs will generally
be in the 60s. We can`t rule out some patchy frost again Saturday
night into Sunday morning, with forecast lows in the mid 30s. The
surface high quickly pushes further off to the east on Sunday while
upper ridging begins expanding across the region, leading to warmer
temperatures in the upper 60s to upper 70s. Highs stay relatively
consistent in the 70s through the middle of next work week, as broad
ridging drifts across the western and central CONUS. Precipitation
chances are very low this weekend through Tuesday, before a more
active pattern begins to emerge in blended POPs, CIPS analogs, and
CPC outlooks. Cluster analysis shows a favored shift to southwest
flow, with forecast instability and potential for stronger to severe
storms emerging for the back half of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 641 PM CDT Wed Sep 3 2025

VFR conditions are expected through tonight. A cold front will
enter northern North Dakota 11-13Z Thursday, with winds quickly
increasing and shifting to northwesterly behind the frontal
passage. Low level clouds and chances for showers will accompany
the front, mainly north central and east (KMOT/KJMS). All
terminals could see wind gusts up to 50 knots during the day
Thursday, and could be erratic around any showers.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 10 AM CDT /9 AM MDT/ to 9 PM CDT /8 PM MDT/
Thursday for NDZ001>003-009>012-017>023-031>037-040>048-050-
051.

&&

$$

UPDATE...NH
DISCUSSION...Jones
AVIATION...NH