745
FXUS63 KBIS 020617
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1217 AM CST Tue Dec 2 2025

.KEY MESSAGES...

- Warmer temperatures, breezy conditions, and low to medium (10
  to 40 percent) chances for light snow showers on Tuesday.

- An active weather pattern is forecast for the rest of this
  week, resulting in periodic low to medium chances for snow,
  breezy conditions, and moderate to large fluctuations in day-
  to-day temperatures.

- Very cold temperatures are forecast Wednesday night into
  Thursday morning, with wind chills possibly as low as 30
  below zero.

&&

.UPDATE...
Issued at 1217 AM CST Tue Dec 2 2025

Surface warm front is moving into western North Dakota, with
current temperatures in the southwest in the lower 20s. Ahead of
the warm front, temperatures have dropped quite significantly,
with midnight temps in the teens below zero in parts of Emmons
and McIntosh Counties. Temperatures are expected to slowly rise
through the overnight hours.

High-res guidance continues to advertise fog potential across
parts of the south central and James River Valley overnight. We
are seeing reduced visibilities in north central South Dakota,
so will be monitoring observation sites, webcams, and nighttime
satellite imagery to see if fog begins to expand north into our
area.

UPDATE
Issued at 1018 PM CST Mon Dec 1 2025

Overall, the forecast for the short term period remains on
track. Lake effect clouds streaming off of Lakes Sakakawea and
Audubon are now being stretched eastward, and there will soon
no longer be cold enough temperatures aloft to support this
feature as warmer air advection commences. 00Z guidance has not
offered any increased confidence in precipitation outcomes
(timing, location, coverage, etc.) for the clipper system on
Tuesday. One thing that has shown up in the RAP though is the
potential for a period of light freezing rain or freezing
drizzle due to a loss of ice nucleation. The pocket of mid level
drier air is forecast to move from northwest to southeast
across the state during the daytime hours. Confidence remains
low in any precipitation actually occurring under the drier air
aloft, even though there could be a deep enough low level
saturated layer with modest lift. If light freezing rain or
freezing drizzle were to occur, the most likely timing and
location appears to be from Williams and McKenzie Counties to
Lake Sakakawea during the mid to late morning hours, but it is
still only a 15 percent chance at most. During the afternoon,
surface temperatures are forecast to rise near or above
freezing, resulting in rain if there is any precipitation
associated with no ice crystal production aloft.

UPDATE
Issued at 628 PM CST Mon Dec 1 2025

High-resolution models show fog, likely in the form of tiny ice
crystals, developing across central North Dakota later this
evening and migrating eastward through the night. Light surface
winds, a mostly clear sky aside from lake effect clouds, and
forecast soundings support this potential. The fog is not
expected to be dense should it develop. A mention of patchy fog
has been added to the forecast to account for this. Most other
changes for this update were to blend in current observations
and trends. Did convert the low chances for lake effect snow to
flurries as there as been no recent ground-truth verification of
any snowfall under the clouds streaming off of Lake Sakakawea.

&&

.DISCUSSION...
Issued at 302 PM CST Mon Dec 1 2025

Cold temperatures will continue through this evening into the
start of the overnight hours. Lake effect snow showers south and
east of Lake Sakakawea will also be found into the early evening
hours, diminishing later this evening or early overnight.
Warming westerly flow aloft with a warm return southerly flow at
the surface will start warming temperatures late tonight.
Forecast lows tonight will generally be near zero to around 10
degrees, although may occur earlier in the overnight hours.
Warming temperatures then look to be found on Tuesday, with
highs currently forecast in the mid 20s to mid 30s. NBM produced
even warmer temps than currently published, however lowered
these to the NBM50th percentile given abundant snow depth across
the area. Upper level wave and clipper system will move through
the state Tuesday as well. This could still bring snow showers,
although confidence in pops is low to medium as current hi-res
data not showing a lot of organized snow showers. Tuesday
morning may have the more increased chances for pops with better
synoptic forcing and some frontogenesis potential. However,
current models hinting the upper wave may outrun the surface
features, making organize snow isolated to scattered. NBM
currently has 10 to 40% chances for accumulating snow across the
CWA with the higher chances coming in the southwest. Chances
for at least an inch are around 10 percent or less. The front
and wave still look potent thus placed in widespread slight
chance for snow at this time. Later in the day Tuesday through
Tuesday night, cold front moves through bringing low clouds and
perhaps some light snow. There could be a small window freezing
rain or freezing drizzle is possible during this time period, if
the mid layers dry out quicker. Breezy winds could also bring
some patchy blowing snow on Tuesday through Tuesday night.
Behind the mentioned front cold temperatures move in Tuesday
night into Wednesday morning, with lows forecast up to 10
degrees below zero. Some isolated dangerous winds chills are
possible. Dry and cold conditions look to be found on Wednesday,
with highs in the single digits to teens. Breezy northwest
winds may also linger. Some isolated lake effect snow showers
may again be possible near Lake Sakakawea. Below zero
temperatures return Wednesday night into Thursday morning. If
steady northwest winds linger through the night, then perhaps
some near Cold Weather Advisory wind chills are possible, mainly
in the southeast.

A series of weak waves in northwest flow may then push through
to end the week Thursday and Friday. Each bringing low (around
20%) chances of snow. Slightly warmer temperatures will
accompany these waves, with highs in the 20s to lower 30s and
lows in the single digits to teens. Perhaps some breezy winds
also return with these disturbances. Better chances for snow
then look to return Friday night through Saturday night. A
similar wave as this past weekend is starting to show up in the
clusters, indicating more accumulating snow is possible. Chances
for at least 2 inches of snow in a 24 hour period to start the
weekend are around 20 to 50 percent. These chances lower yet
remain 10 to 20 percent later in the weekend. High accumulations
will depend on where a surface front sets up and the location of
the surface low. Current temperature forecast through the
weekend remain near to below normal, depending on where the
front sets up. This uncertainty in front location likely is the
reason for large spreads in NBM temperatures. Overall those with
travel plans this weekend will want to keep up to date on the
latest forecast.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1217 AM CST Tue Dec 2 2025

VFR conditions at all terminals to start the 06Z TAF period.
Areas from around KBIS to KJMS could see low clouds or fog
develop overnight tonight, although too low of confidence in
occurrence and location to include with this update. MVFR
ceilings are forecast to develop from west to east during the
day Tuesday. There will also be low chances for light snow at
times, but again, too low of confidence to include any any
particular terminal for now. Light west to southwest winds
through tonight will become west to northwest on Tuesday around
15 knots, with some 25-30 knot gusts possible in the afternoon.

&&

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

&&

$$

UPDATE...Jones
DISCUSSION...Anglin
AVIATION...Jones