519
FXUS63 KBIS 010216
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
816 PM CST Sun Nov 30 2025

.KEY MESSAGES...

- Well below average temperatures will continue through Monday.
  Wind chill temperatures as low as 25 below zero are possible
  tonight into Monday morning.

- Scattered flurries and patchy fog are possible across central
  and parts of northwest North Dakota this evening through
  tonight.

- An active weather pattern is forecast for the upcoming 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 as low as 30 below zero.

&&

.UPDATE...
Issued at 814 PM CST Sun Nov 30 2025

Some parts of western North Dakota are observing enhanced
southerly winds this evening, as high as 20 mph sustained. These
winds are mostly in a cloud free area where temperatures have
already fallen to around 5 to 15 below zero. This is resulting
in wind chills around 25 to 30 below. We do not anticipate that
winds this strong will continue for much longer. But if they do,
there should be enough mixing of the near surface layer to
raise temperatures (and effectively wind chills) by a few
degrees.

UPDATE
Issued at 644 PM CST Sun Nov 30 2025

A diffuse low level baroclinic zone with weak warm air
advection is analyzed over western and central North Dakota
early this evening on the back side of a departing surface high
pressure. Water vapor and mid/upper height analyses also show a
weak shortwave moving down from Saskatchewan. This is resulting
in an area of low stratus producing occasional flurries as well
as ice crystals/fog along the Highway 83 corridor and surrounding
areas. There is also some lake enhancement to the flurries/ice
crystals/fog to the north of Lake Sakakawea. Within the last 3
hours, visibility as low as 1 mile was reported near Steele, and
we have also measured one tenth of an inch of new snow
accumulation at our office. Model guidance suggests a slow
eastward migration of the excessive low level moisture (with
respect to ice) through tonight, but the western edge could
stall into the late night hours. Forecast mentions of flurries
and fog, along with sky cover, have been updated to reflect
these thoughts and trends.

&&

.DISCUSSION...
Issued at 304 PM CST Sun Nov 30 2025

Surface high will continue its slow progression eastward through
tonight. Low level moisture trapped under this high has brought
low clouds and patch to areas of fog all day. This trend could
continue through tonight, although predictability on the exact
location of this is low. High Res fog guidance now showing fog
redeveloping in much of central and portions of eastern North
Dakota. This could also indicate low clouds may linger in these
areas through tonight. There is an upper level wave forecast to
move through later tonight into Monday morning, which may help
diminish these clouds and fog. For now have placed in patchy fog
mention to these central and eastern areas. Cold temperatures
aloft and southerly flow has been enough to bring some light
lake effect snow showers to the northern shores of Lake
Sakakawea and especially the Van Hook Arm area. Lake effect snow
potential could continue until warmer temperatures at the 850 mb
layer move in with the mentioned upper level wave later tonight
or early Monday morning. For now have mention of snow flurries
to account for this potential. Lows tonight will dip below zero
for many areas. Increased cloud cover could limit this
potential, although clearing skies could bring colder
temperatures. Wind chills are forecast to remain above advisory
criteria, although could get close in some areas. Upper level
wave moves through on Monday, with a weak surface high in its
wake. The result could be slightly warmer yet still below
normal temperatures across the area. This wave could bring some
increased northwest winds. Mainly dry conditions are also
expected. Winds will switch to the northwest, which could favor
some return of lake effect snow. 850 mb winds may be just
slightly too warm though for these to take shape. An approaching
surface low will then switch winds to the west southwest Monday
night, perhaps bringing warming temperatures through the now.
Mainly dry conditions are also expected.

A brief warmup will then be found with this clipper system for
Tuesday, with highs returning into the mid 20s to mid 30s for
most areas. This system may also bring at least slight chances
for snow as it moves through Tuesday through Tuesday night.
Currently models show limited moisture with this system, with
the NBM chances for measurable snow in 24 hours currently at 10
to 40%, and the chances for at least an inch generally less than
10 percent. This clipper could also bring breezy northwest
winds, perhaps leading to some blowing snow potential although
warm temperatures and lack of fresh snow may limit this. Chances
for light snow may then linger through Tuesday night as the cold
front associated with this clipper moves through. Near to below
zero temperatures may also return, with lingering breezy winds
bringing some cold wind chills. Cold yet mainly dry conditions
then look to be found Wednesday through Wednesday night.
Trapped moisture could once again bring lingering low clouds and
perhaps some fog as well, although breezy northwest winds could
persist into Wednesday. Very cold temperatures are forecast for
Wednesday night as the surface high exits the area. This could
lead to some dangerous wind chills perhaps getting into advisory
level criteria.

Clusters indicate trough pattern could persist late next week
into the weekend, with individual solutions showing part of this
pattern could include a more moist westerly flow. This could
provide for better chances of accumulating and perhaps the
return to more seasonable temperatures. NBM has high
temperatures spreads currently, indicating some uncertainty to
this pattern change. There is some increased chances for at
least an inch of snow in a 24 hour period through the weekend,
with NBM chances up to 50% at times. This same pattern could
also bring periods of breezy winds at times.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 814 PM CST Sun Nov 30 2025

MVFR/IFR stratus producing ice crystals/fog and occasional
flurries will impact much of central North Dakota through this
evening, with a slow eastward migration and erosion forecast
late tonight into Monday morning. There is a low chance that
more widespread MVFR ceilings could develop Monday afternoon,
but forecast confidence in this is not high. Winds will
gradually turn from southerly to westerly at around 10 kts
through the forecast period, with some stronger southerly winds
possible across parts of western North Dakota this evening.

&&

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

&&

$$

UPDATE...Hollan
DISCUSSION...Anglin
AVIATION...Hollan