438
FXUS63 KBIS 250416
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1016 PM CST Mon Nov 24 2025

.KEY MESSAGES...

- Snow will fall across most of western and central North Dakota
  tonight through Tuesday afternoon. The highest snow amounts
  are forecast to be along a line from Crosby to Garrison to
  Jamestown, where 4 to 9 inches of snow are possible.

- Strong northwest winds, with gusts around 45 mph, are forecast
  late tonight through Tuesday. Snow combined with the strong
  winds will cause areas of blowing and drifting snow.

- There remains increased confidence in a very cold and possibly
  snowy pattern after Thanksgiving, which could lead to
  additional travel concerns for the end of the holiday weekend.

&&

.UPDATE...
Issued at 1016 PM CST Mon Nov 24 2025

At 10 PM CST, a deepening surface low was analyzed over west central
North Dakota, just downstream of the mid level trough. Precipitation
has become much more widespread across the western half of the state
this evening, as anticipated. The rain/snow transition line is
generally located along Highway 200 from around Grassy Butte to
Washburn, and continues to advance southward. 00Z high-resolution
guidance continues to paint a swath of +6" from around Crosby to
Garrison to Wahpeton, which is a slight shift south over central and
eastern North Dakota. But these amounts may be slightly overdone
when considering initial melting on contact (until snowfall rates
sufficiently increase) and compaction. The latest NBM mean snowfall
also now shows a 6-8 inch swath from around Sheridan to LaMoure
Counties. This may be the area most likely for a potential upgrade
to a Winter Storm Warning in future updates.

UPDATE
Issued at 726 PM CST Mon Nov 24 2025

As of 7 PM CST, snow was falling across northwest North Dakota
as far east as New Town and as far south as Killdeer, but not
yet over all of McKenzie County. Areas from around Crosby to
Williston have been observing snow for around 2 to 3 hours.
Recent webcam imagery from that part of the state implies
moderate to heavy snow at times, and there is now accumulation
on roadways.

The major forecast challenge for tonight will be whether any
parts of the state require an upgrade to a Winter Storm Warning.
The signal for mesoscale banding is not that prevalent, with
just a transient area of 850 mb frontogenesis projected by the
RAP from northwest to central North Dakota later this evening.
The intense synoptic scale lift combined with a deep layer of
steep mid level lapse rates, including through the dendritic
growth zone, may be sufficient to produce a swath of +6 inches
on its own. But there are still several factors contributing
uncertainty to forecast snow amounts. One is how quickly rain
will change over to snow. Recent rapid-refresh guidance is a
little too slow on this transition compared to what is being
observed, which could drive snow totals higher. The progressive
nature of this system has been discussed as a deterring factor
for higher end amounts, but recent CAMs have been consistent in
painting and oblong precipitation shield whose major axis is
closely aligned with the system`s trajectory. There is also
still uncertainty in the location of highest amounts, with
recent rapid-refresh guidance taking another slight shift to the
south and bringing the highest amounts through Bismarck.
Because of this uncertainty, we remain comfortable with a high-
end Winter Weather Advisory for now. But observed and modeled
trends will need to be monitored closely through the night.

&&

.DISCUSSION...
Issued at 240 PM CST Mon Nov 24 2025

Currently the state is under zonal flow, and switching to
southwest flow. A shortwave trough is starting to dig through
Montana, this will be our snow producer later. Another low
pressure area sits in the Central Plains. At the surface higher
pressure is being forced out of the northern part of the state,
with pressure falling elsewhere. There is currently a surface
trough located in western North Dakota, moving east. With it is
a light rain/snow/ice pellet mix.

A Winter Weather Advisory has been issued for almost all of the
state, except the far northeast, this evening through Tuesday
night. With the 12z and 15z models, there has been a slight
southern shift in the northwest to southeastern track. This
combined with the strong winds, led to the decision to go CWA
wide Advisory. In this northwest to southeast track, there is a
potential for up to 9 inches of snow, otherwise its a wide path
of 4 to 6 inches. The NBM might have too high of snow totals and
probabilities, but the chance of at least 4 inches is 50 to 80
percent in that track. For greater than 6 it drops to around 50
percent, but again the NBM might be too aggressive, but so is
every other model. We are leaning more on the lower end of those
probabilities because the system seems very progressive over
the Dakotas. Once it gets to Minnesota, the upper low looks to
wrap up and deepen which will slow down and produce more snow.
When and if we see the snow band setup, and we are confident in
a swath of at least 6 inches, when we will upgrade those
counties to a Warning.

This is mostly a synoptic driven system with an open shortwave
deepening and wrapping up to the east of the Dakotas. Across all
models the Q vectors are very strongly negative across the
northwest, central, and southeastern portions of the state. The
models differ where the vectors turn positive again, where this
happens, the snow totals will drop significantly (in the
positive values). Some models have that line near the Missouri
River, others have further into the southwest. Lapse rates with
this system are very healthy with values around 8 degrees C per
km. The surface low should be coupled with the 700mb low, both
moving through southwest and south central North Dakota. There
will also be some Frontogenesis forcing with this system too.
There is some model disagreement in the location of it, but the
consensus seems to be around the Missouri River or south. This
mostly lines up with the swath of higher snow totals.

The pressure gradient force on the backside of the low is going
to be very strong. Creating strong northwest winds kicking up
tonight through Tuesday. The pressure bubble is also very
strong, but we are actually on the northern end of it. The
majority of the strong pressure bubble will stay in South
Dakota. For this reason we do not have any wind headlines out
yet, just in South Dakota. If winds start to increase to a High
Wind Warning level (likely in the southwest), then that will be
issued too. Overall it will for sure snow across most of North
Dakota, we are just less confident in amounts and exact
location for the highest amounts at this time.

After this system fully moves out Wednesday, temperatures will
be well below average in the 20s for highs. Low temperatures
will be in the single digits above zero this week and below
zero this weekend. Another front and weak wave could impact the
Northern Plains this coming weekend, but there is a lot of
uncertainty with timing and location.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 1016 PM CST Mon Nov 24 2025

A low pressure system will bring widespread aviation impacts
across the state through the forecast period. Snow is already
falling in northwest North Dakota and is expected to rapidly
spread southeastward through tonight. The snow is expected to
end from west to east Tuesday morning and afternoon. IFR to LIFR
visibility can be expected with the falling snow. Ceilings are
also expected to lower to MVFR/IFR levels this evening through
tonight, with improvement from the west Tuesday afternoon. Winds
will become north to northwest and strengthen later tonight
through Tuesday, with sustained speeds around 20-25 kts and
gusts as high as 30-40 kts. The wind may cause areas of blowing
and drifting snow beyond when falling snow ends.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight CST /11 PM MST/ Tuesday
night for NDZ001>003-009>013-017>023-025-031>037-040>048-050-
051.
Winter Weather Advisory until noon CST Tuesday for NDZ004-005.

&&

$$

UPDATE...Hollan
DISCUSSION...Smith
AVIATION...Hollan