043
FXUS63 KBIS 101155
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
555 AM 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 possible across the west and south central 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 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 protions 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 /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 555 AM CST Wed Dec 10 2025

MVFR ceilings and flurries can be found over portions of
northern and south central North Dakota this morning, including
at the terminals of KMOT and KJMS. Conditions are expected to
improve from west to east as high pressure builds in across the
area. Late this afternoon through the evening, chances for
precpitation and MVFR to IFR ceilings will increase from west to
east as a low pressure system passes through the northern
Plains. Periods of moderate snowfall are possible across the
west early this evening through early tonight. A transition to
freezing rain is expected late this evening and overnight across
portions western and south central North Dakota, with ice
accumulations from 0.001 to 0.10" possible across this area.
Brief periods of ice pellets are also possible across the south
central during this transition period, though confidence remains
too low to include at any given TAF site at this time. Thursday
morning through Thursday afternoon, another transition to all
rain and light snow is anticipated. Northwest wind this morning
remain moderately strong, with speeds broadly from 20 to 25
knots and gusts up to 30 to 35 knots observed. As surface high
pressure moves from the northwest this morning, winds are
expected to diminish turn variable through the afternoon. As the
aforementioned low pressure system starts to move into the area
this afternoon, a general reorganization out of the south
southeast is expected, with winds becomes somewhat gusty through
the evening and overnight.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 3 PM CST /2 PM MST/ this
afternoon to 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...Adam
DISCUSSION...Adam
AVIATION...Adam