028
FXUS63 KBIS 021745
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1145 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 today.

- 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 tonight into Wednesday
  morning and Wednesday night into Thursday morning, with wind
  chills possibly as low as 30 below zero.

&&

.UPDATE...
Issued at 1145 AM CST Tue Dec 2 2025

Surface analysis shows the warm front having made it to the
James River Valley at the time of this mid day update.
Temperatures at this time are broadly from the lower to mid 30s
west to lower 20s east. Weak radar returns continue in the far
northeast and far southwest at this time, though precipitation
reports have been fairly rare so far. No major adjustments to
the forecast were performed with this update.

UPDATE
Issued at 935 AM CST Tue Dec 2 2025

Scattered weak radar returns can be found over northeastern and
southwestern North Dakota at the time of this late morning
update. While much of this precipitation isn`t reaching the
ground, a developing jet streak over the northeast has allowed
some light snow to develop in the far north central into the
Turtle Mountain regions. More light snowfall is expected later
today in the southwest. Expected accumulations remain low at
this time, less than an inch overall. Otherwise, a warm front is
passing from west to east across the state this morning, with
surface analysis placing it roughly along the Highway 84
corridor at this time. Breezy west to northwest winds and highs
in the 30s are expected behind this front this afternoon. With
this update, have blended the latest CAMs into the PoPs, and
ingested satellite trends into the sky grids. Otherwise, the
forecast remains broadly on track.

UPDATE
Issued at 627 AM CST Tue Dec 2 2025

Surface analysis shows center of the low has shifted to
southeast Saskatchewan, with the attendant warm front extending
north-south through western and into central North Dakota,
generally from Renville County through western Morton County and
south. West of this boundary, current temperatures are in the
20s, while to the east, we still have many locations in the
south central and southeast i the single digits above zero.
Areas to the north that have been under persistent cloud cover
all night are in the teens.

We`re starting to see more persistent, although scattered, radar
returns across the north central and southwest, although still
not seeing any evidence of surface precipitation at this time.
More widespread radar echoes are visible upstream in central
Montana, closer to the main shortwave and vort max moving
through. Made some minor tweaks to POPs, but no significant
changes in expectations for today.

&&

.DISCUSSION...
Issued at 320 AM CST Tue Dec 2 2025

Early this morning, broad cyclonic flow aloft due to a Hudson
Bay low dominated the synoptic pattern across the Northern
Plains, with a deepening surface low analyzed in south central
Saskatchewan. A warm front extended south of this surface low
and was placed north-south across western North Dakota, with
winds shifting to be westerly and much warmer air moving into
the area. Ahead of the warm front across central North Dakota,
temperatures were in the single digits above and below zero,
with the coldest area in the southern James River Valley along
the South Dakota border. Some light radar returns were ongoing
across our northernmost tier of counties, but higher ceilings in
this area are likely limiting any precipitation from making it
to the surface, at least for now.

The main weather concern in the near term is for fog and
subsequent reduced visibilities through the early morning, with
Harvey / Wells County the only area with any fog as of 08 UTC.
High-res guidance has been adamant on significantly reduced
visibilities across parts of the south central and southeast,
and there has been fog across the state line in north central
South Dakota, but that has yet to expand north.

Focus then turns to precipitation expected today and into
tonight as a shortwave moves across the region. Latest CAMs are
primarily emphasizing two areas of potential precipitation: one
in north central and northeast North Dakota, in line with an
upper level jet streak, and one in Montana and southwest North
Dakota, where the bulk of the forcing from the upper wave is
projected to track. This leaves the majority of the forecast
area in between these two areas, but opted to carry a broad 20
POP, with higher POPs across the north central and southwest.

We also cannot rule out a brief period of a wintry mix,
primarily in the northwest and west-central parts of the state,
as deterministic guidance is advertising a dry pocket and
potential loss of ice aloft. However, latest forecast soundings
have backed off this potential a bit, so would give this a low
probability outcome through the morning hours before expectation
would be for rain/snow p-types. Any snow accumulations should
be light and only a few tenths of new snow.

Breezy westerly winds are in the forecast as well today, with a
modestly tight surface pressure gradient. Typically that leads
to over performance of forecast high temperatures, but with a
robust snowpack in place across the forecast area, opted to go
with the NBM 50th percentile for today`s highs. This puts
forecast highs in the mid 20s to mid 30s, with a short-lived
warmup behind the aforementioned warm front. The surface low`s
attendant cold front quickly drops south tonight, taking
overnight lows back into the single digits below zero (north)
and above zero (south). Arctic high pressure builds in on
Wednesday, helping partially clear skies out but keeping
temperatures mainly in the single digits for highs, and some
lower teens southwest. Apparent temperatures could be
approaching 30 degrees below zero both tonight and Wednesday
night.

Ensemble guidance is fairly conclusive on broad cyclonic flow
dominating the synoptic pattern through the rest of the week,
the weekend, and into next week. This means moderate to large
fluctuations in day-to-day temperatures and on and off chances
for precipitation that are relatively low predictability more
than a few days out. Temperatures moderate again for Thursday
and Friday as blended POPs are broadly 20 to 30 percent, with
deterministic guidance showing embedded shortwaves tracking
through the northwest flow. The more notable wave that has
potential to bring more than light accumulations arrives Friday
night through Saturday.

The varying solutions advertised by cluster analysis all show
accumulating snow during this period, increasing confidence in
the general expectation. Newest NBM guidance produces a general 20
to 40 percent chance of at least 2 inches of snow, with a 5 to
15 percent probability of at least 6 inches of snow. There`s
also modest agreement on both mid-level frontogenesis and
Q-vector convergence being present in the general area, which
would indicate banded snow potential, although we won`t be able
to resolve any details on this until much closer to the event.

There is high confidence on temperatures cooling down for the
weekend, although a large spread in NBM temperature percentiles
indicates there are still questions on how cold temperatures end
up. We`re then favored to moderate to near normal to start next
week, with a continued active pattern showing up in NBM
probabilities, CIPs extended analogs, and the CPC 6-10 and 8-14
day outlooks.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1145 AM CST Tue Dec 2 2025

MVFR ceilings have begun to move into the northern portions of
the forecast area at the start the 18Z TAF period. Light snow
is possible across portions of southwestern North Dakota this
afternoon through early tonight, and across portions of the far
north central into the northern James River Valley through this
afternoon. With this update, have added PROB30 groups at KDIK,
KMOT, and KJMS. MVFR ceilings are expected to continue spreading
across the forecast area, including over all terminals, through
this afternoon and evening. Periods of IFR ceilings are also
possible, especially in the southwest and where light snow does
develop. Ceilings are anticipated to start lifting through
Wednesday afternoon. Breezy west winds are expected this
afternoon, turning north westerly overnight as a cold front
drops in from the southern Canadian Prairies. Winds are
anticipated to diminish through mid to late Wednesday morning.

&&

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

&&

$$

UPDATE...Adam/Jones
DISCUSSION...Jones
AVIATION...Adam