179
FXUS63 KBIS 111001
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
401 AM CST Thu Dec 11 2025

.KEY MESSAGES...

- Snow and freezing rain are expected across much of western and
  central North Dakota through this afternoon.

- Well below average temperatures are expected through the
  upcoming weekend, with dangerous wind chills this evening
  through Sunday morning.

- Another round of accumulating snow could impact areas mainly
  south and west of Lake Sakakawea and the Missouri River Friday
  afternoon through Saturday morning.

&&

.DISCUSSION...
Issued at 400 AM CST Thu Dec 11 2025

Currently, satellite and radar show a narrow band of light snow
along the Highway 83 corridor, pushing east through central ND.
East of this band, the atmosphere has not saturated enough to
produce precip at the surface. Behind the band, mainly along and
west of the highway 83 corridor, we are saturated enough that we
are seeing a mixed bag of snow and light freezing rain/freezing
drizzle, until you get into the far southwest, where
temperatures have climbed above freezing, and precipitation is
rain.

For today, a band of heavier precipitation over northeast
Montana will track across western and central ND, with the axis
of the precip tracking from mainly west central ND into the far
south central. This looks to be the focus for the heaviest
accumulations of freezing rain. There are still uncertainties,
mostly in precipitation amounts, but the general area seems
pretty consistent. The HREF probability of a tenth of an inch or
more of freezing rain is indicating medium probabilities (40-60
percent) over southern Grant and Much of Sioux counties, with
low probabilities over eastern portions of Stark, Hettinger and
Adams counties, as well as western Morton counties. If you look
at probabilities of two tenths or more, they drop to less than
10 percent over Grant, Sioux and portions of Hettinger and Adams
counties. Our NBM developmental (which is higher than the
operational NBM) probabilities of a tenth of an inch or more of
freezing rain are lower, generally 30 percent or less over
western Grant and Sioux Counties and into far eastern Adams and
Hettinger counties. Recent deterministic runs of the HRRR and
RAP are similar in the placement and amounts. The NAMNest is
also similar in placement, but is a high outlier, and the only
CAM that is currently supporting Warning criteria ice
accumulations. Outside of this area, but generally south and
west of the Missouri River, lesser amounts of freezing rain can
be expected, ranging from a light glaze to less than a tenth of
an inch, which can still produce high impact hazardous travel.
Will continue to monitor for a potential upgrade for a small
area as we get closer to the 12-15Z timeframe, but for now will
continue with our current Winter Weather Advisory, for light
snow and up to two tenths of an inch or freezing rain. The far
southwest, including Bowman and Slope counties, and portions of
Golden Valley, Billings and Stark and possibly western portions
of Hettinger and Adams counties will see mostly rain through
this morning as temperatures here have already climbed above
freezing.

The remainder of western and central ND, will likely see a mix
of light snow/flurries and/or freezing drizzle this morning.
Cold air begins to drop southeast into northwest ND this
afternoon and continues propagating southeast through tonight.
Precipitation this afternoon is expected to transition to either
snow, or rain in the far southwest. There looks to be a period
of light snow associated with the Arctic front, but until it
passes, there could be a mixed bag of snow flurries and freezing
drizzle in northern and eastern portions of the forecast areas,
outside of the ongoing Winter Weather Advisory.

Later tonight we see the very cold Arctic air enter the state.
It is likely that we will need Headlines for Cold air late
tonight over northwest ND, and towards Friday morning for
portions of central ND along, north and east of Lake Sakakawea
and and into the northern James River Valley. The timing of
arrival of the coldest air is such that it may be best to let
the day shift take another look. It`s possible that northern
portions of the forecast area may be handled with more of a
long term Advisory, through at least a portion of the weekend, but
areas farther south would likely not reach this criteria. Being
it`s a late arrival tonight, it may be best to let the day shift
take another look.

In addition to the Dangerous wind chills, patchy blowing and
drifting snow is possible, mostly where we are able to see any
light snow accumulations today. Otherwise, the warm temperatures
and shot of freezing rain earlier this week have put a crust on
much of the snow. The north central into the northern JRV would
be the areas where some blowable snow still remains.

The next shot of snow from Friday afternoon through Saturday
morning looks to remains mainly south and west of Lake Sakakawea
and the Missouri River, with a moderate 40-70 percent chance of
at least two inches mainly confined to far west central and
southwest North Dakota. One thing to note with this snow,
Bufkit soundings indicate that the entire column from the
surface to around 600 mb is within the DGZ, which could yield
some very high snow ratios. This could lead to some over
achieving amounts of light fluffy snow.

After this bout of snow it looks like we may dry out through the
remainder of the weekend and into early next week. The very cold
wind chills will continue through Sunday morning, but look to
retreat quickly on Sunday as we see strong ridging build over
the region. We`ll see if the current NBM temperatures hold, but
we the NBM is already depicting highs into the low to mid 40s by
Tuesday across much of western and central ND, along and west of
the Highway 83 corridor. Generally following an Arctic airmass,
the warmup can be slower to arrive than forecast. However, there
is good agreement in the pattern shift. NBM ensemble spreads,
especially over western ND, are really pretty low, adding
confidence in a very noticeable warmup early next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1200 PM CST Wed Dec 10 2025

A band of light snow will move from west to east from western
into central ND tonight. Primarily low VFR-MVFR visibility with
the snow, but with a few periods of LIFR possible. Trailing the
snow is the potential for a period of freezing drizzle or light
freezing rain. Southwest North Dakota into the far south
central, will see a more persistent band of freezing rain, and
transitioning to rain closer to the Montana border, through
tonight. By 12Z, widespread precipitation is expected along and
south of a line from KXWA to KJMS, with freezing rain (rain in
far southwest North Dakota) transitioning back over to snow.

Ceilings are forecast to lower through tonight, reaching at least
IFR at most terminals Tuesday morning. Generally light and
variable late tonight into this morning, then northwest around
10-15 kts (strongest in western North Dakota) this afternoon.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM CST /5 PM MST/ this evening
for NDZ009-010-017>021-031>035-040>046-050.

&&

$$

DISCUSSION...TWH
AVIATION...TWH