173
FXUS63 KBIS 101818
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1218 PM CST Wed Dec 10 2025

.KEY MESSAGES...

- Another round accumulating snow is expected late this
  afternoon through Thursday night. Areas of freezing rain are
  also expected across the west and south through late Thursday
  morning.

- Below average temperatures are expected today through the
  upcoming weekend, with dangerous wind chills possible Thursday
  evening through Sunday morning.

- More accumulating snow is possible across the west and south
  central Friday through early Saturday.

&&

.UPDATE...
Issued at 1215 PM CST Wed Dec 10 2025

The low clouds mostly broke up across the central and east. What
is left is lake effect stratus from Sakakawea. Moisture in the
form of high clouds from the Atmospheric River event in
Washington has entered the state ahead of this evening`s next
snow system. The latest NBM has been loaded into the forecast,
and not much as changed in terms of p-types and timing.

UPDATE
Issued at 900 AM CST Wed Dec 10 2025

Very light snow continues to fall sporadically in the central
and east under the low cloud deck. These clouds will slowly move
east with surface high pressure and then the incoming next
system. No major changes where made to the on going forecast.

UPDATE
Issued at 555 AM CST Wed Dec 10 2025

Low level clouds linger over northwestern and central North
Dakota this morning. Flurries have be observed across portions
of this cloud deck, and have added such to the forecast through
the mid to late morning. Flurries and clouds should diminish
from west to east as surface high pressure moves in this
morning. Otherwise, this morning, gusty northwest winds linger
over portions of the central North DAkota, with speeds broadly
from 15 to 25 MPH and gusts up to 35 MPH observed. These winds,
too, should diminish as high pressure moves in this morning.
Other than the aforementioned update mentioned above, the
forecast remains broadly on track.

&&

.DISCUSSION...
Issued at 415 AM CST Wed Dec 10 2025

Northwesterly flow is found over the northern Plains this
morning. Light wintry precipitation lingers over north central
North Dakota into the northern James River Valley, trailing
along and behind a inverted surface trough associated with the
clipper system that passed through North Dakota yesterday. A
transient upper level ridge is expected to move through the
northwesterly flow pattern this morning through much of the day,
and will allow high pressure at the surface to move into the
northwest. While this will help further erode precipitation and
the somewhat gusty northwest winds that lingered overnight.
Before that time light, non accumulating snow will remain
possible over portions of north central North Dakota into the
northern James River Valley through this morning. Clearing
conditions are then anticipated through the late morning and
afternoon as high pressure slides across North Dakota. Low
temperatures this morning are from the lower single digits below
north, to the upper single digits to mid teens above south.
High temperatures this afternoon are forecast from the upper
single digits to mid teens central, to the lower 20s to lower
30s west.

Another round of impactful winter weather is expected early
this evening through Thursday as another upper level wave passes
through the northern Plains. Chances for precipitation will
increase as strong 850-700mb WAA pushes in across the west,
accompanied by decent FG forcing. At the fore of this system,
periods of moderate to heavy snowfall will be possible across
the west this evening through early tonight as the
aforementioned FG forcing aligns with decent Q vector
convergence. Then, in a similar setup to Tuesday, a ongoing WAA
will cause a deep warm nose aloft, allowing for a switchover
from snow to freezing rain across the west and south central
overnight through late Thursday morning. During this transition,
portions of southwestern and south central North Dakota may
experience precipitation in the form of ice pellets, as the
initially elevated nature of the warm nose aloft could allow for
refreezing of falling liquid before it reaches the surface.
CAMs remain somewhat discordant on the exact cessation time of
the freezing rain, mainly due to differences in when the warm
nose aloft erodes. A good majority of the CAMs favor an initial
weak slug of CAA moving in out of the northwest mid to late
Thursday morning, which will allow for a slightly quicker
change-over to all rain and snow across the forecast area. A
minority of CAMs instead favor WAA continuing through the late
morning, early afternoon period which would allow freezing rain
to continue across south central North Dakota for a little
longer. In either scenario, the cold front associated with the
low pressure system is then expected to move in out of the
northwest, and facilitate a complete conversion to snow through
the remainder of Thursday. As of the current forecast cycle, NBM
5.0 Calibrate probabilities has medium to high chances (50 to
80 percent) for at least 0.001" of ice accumulation across much
of western and portions of central North Dakota, with
probability dropping off quickly north of Highway 200. Chances
for 0.10" are generally low (10 to 20 percent) across much of
the same area, though a small area of medium (30 to 40 percent)
can be found in south central North Dakota, mainly along and
east of the Missouri River and south of I-94. This area would
have the greatest residence time for freezing rain overall, not
to mention the scenario where it lingers into the early
afternoon mentioned above. With banding potential Wednesday
afternoon and evening, and with the freezing rain overnight
through Thursday morning, A Winter Weather Advisory is in effect
across western North Dakota start 3 PM CST Wednesday, then
expanded to include portions of central North Dakota starting 6
PM CST Wednesday, through 6 PM CST Thursday. With this update,
we have opted to start the Advisory a little earlier across the
west due to potential for moderate snowfall to start late
Wednesday afternoon.

After the cessation of freezing rain, lightly accumulating snow
is then expected to continue across much of western and central
North Dakota from the remainder of Thursday afternoon through
late Thursday night, perpetuated by an incoming arctic cold
front Thursday evening. When all is said and done, much of
western and central North Dakota has medium to high (30 to 60
percent) probabilities to exceed 1.0 inches of snow through
Friday morning, with low to medium probabilities to exceed 2.0
inches overall.

The aforementioned arctic cold front will bring much colder
temperatures and gusty winds starting Thursday night through
Friday, and addition to the light snowfall through Friday
morning. Low temperatures Friday morning are forecast from the
mid teens below zero north, to around zero south. With these
temps, with northwesterly winds with speeds from 15 to 20 MPH
and gusts up to 30 MPH overnight, there are medium to high
chances (50 to 80 percent) for dangerously cold wind chills
below -30 across the northern portions of the forecast area
Friday morning, mainly north of Highway 200 plus the northern
James River Valley. That being said, a slightly faster
progression of the cold front overnight could allow for this
potential area to spread further to the south. High temperatures
Friday morning are also very cold, with much of northwest and
central North Dakota unlikely to rise above freezing. Saturday,
if anything, will be even cooler across the north, though less
windy than Friday. Low temperatures Saturday and Sunday morning
are broadly forecast as low as -20 in north central North
Dakota, up to around -5 in the southwest and south central.
Despite the lack of winds, there are again medium to high for
portions of northern North Dakota to experience dangerously cold
wind chills both mornings, with the highest potential north
central. High temperatures on Saturday are from -10 north
central, to around 10 above southwest, then warming into lower
teens east to lower 30s southwest on Sunday. Persistant
northwesterly flow will allow for more opportunities for
precpitation essentially each day over the weekend, though
Friday through Saturday is currently looking like our best bet
at the moment. Another low pressure system passing to the
southwest of the forecast area will allow for medium to high
chances (50 to 80 percent) for accumulating snowfall west and
south central. NBM calibrated probabilities for at least 2
inches of snow through Saturday morning are high south and west
of the river, with low to medium chances to exceed 4 inches in
the far southwest for the same period. Looking ahead to next
week, the warming trend starting Sunday is to continues, with
forecast highs broadly back into the 30s and 40s by Tuesday.
CIPS analogues lean toward near to above normal temperatures to
continue through the end of the workweek.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1215 PM CST Wed Dec 10 2025


VFR across the area except for BKN MVFR CIGs in the central and
east. Winds will be breezy today in the west with southeast
winds gusting to 25kts. This evening another round of snow will
be moving west to east, switching to freezing rain early
Thursday across the west and south. Then mostly snow will fall
through Thursday morning with rain in the southwest. CIGs with
the precip will be IFR and VIS 4SM or lower.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM CST /5 PM MST/ Thursday for
NDZ009-017-018-031>033-040-041-043-044.
Winter Weather Advisory from 6 PM CST /5 PM MST/ this evening
to 6 PM CST /5 PM MST/ Thursday for NDZ010-019>021-034-035-042-
045-046.

&&

$$

UPDATE...Smith
DISCUSSION...Adam
AVIATION...Smith