525
FXUS63 KBIS 271205
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
605 AM CST Thu Nov 27 2025

.KEY MESSAGES...

- Areas of fog across portions of western and central North
  Dakota will linger through the mid to late morning. Another
  round of fog is them possible this evening through Friday
  morning.

- There are medium to high chances (70 to 90 percent) for
  accumulating snowfall Friday and Friday night across portions
  of western and south central North Dakota.

- Well below average temperatures are favored for this coming
  weekend and into early next week. Wind chill temperatures as
  low as 25 below zero will be possible both Saturday night and
  Sunday night.

&&

.UPDATE...
Issued at 605 AM CST Thu Nov 27 2025

Areas of dense fog linger across much of northwestern and
portions of south central North Dakota this morning, and
continues to slowly expand to the southwest. At the same time,
fog has slowly begun to lift across the northern and eastern
edge of this stratus deck. With this update, have clipped
Renville, Sheridan, and Kidder counties from the Dense Fog
Advisory, while adding Stark, Grant, and Sioux counties.
Visibilities are broadly expected to improve through the mid to
late morning, though some patchy fog may linger in the northwest
and south central through the early afternoon. With this update,
have tweaked cloud cover and the fog to account for the latest
satellite trends. Have also started the fog this evening
slightly earlier to account as per model trends. Otherwise, this
morning, low temperatures around or slightly below zero can be
found across the west and far south central, up to the lower
positive teens in the north central and in the James River
Valley.

&&

.DISCUSSION...
Issued at 400 AM CST Thu Nov 27 2025

Northwesterly flow can be found across the northern Plains this
morning. At the surface, high pressure continues to bleed into
northwestern North Dakota this morning out of the southern
Canadian Prairies. With the resulting calm winds, and with
plenty of snow pack across much of northern and central North
Dakota, areas of fog and low stratus lingers across the
forecast area. Visibilities across portions of northwestern and
south central North Dakota, where winds are weakest, have
dropped as low as 1/4 SM. With high clouds pushing in the
southwest, fog has struggled to develop outside of shallow
valleys. A Dense Fog Advisory remains in effect through the mid
morning across portions of northwestern and central North
Dakota. Fog is generally anticipated to lift through the late
morning, though may linger over portions of the northwest and
north central through the early afternoon. Otherwise, isolated
flurries are also possible across portion the James River Valley
this morning. Low temperatures are broadly in the positive
single digits under the stratus deck. Where skies remain
somewhat clear, mainly in the southwest and far south central,
lows in just below zero are expected. Highs temperatures this
afternoon are broadly expected to be from the mid to upper 20s
in the far southwest, to the upper teens to lower 20s elsewhere.
Areas of fog are again possible across the northwest and
central this evening and overnight across northwestern and
portions of central North Dakota, though are anticipated to
start lifting by the early to mid morning Friday.

Late tonight through early Friday, an upper level low in the
Pacific Northwest is expected to merge into the general
northwestern Flow over Idaho/western Montana. The resulting
shortwave and associated surface low pressure system is expected
to induce widespread snowfall across the region Friday
afternoon through the weekend. The trajectory of this system is
such that the bulk of the this snowfall is expected to fall to
the south and east of North Dakota, though wintry precipitation
developing along and behind a surface trough/cold front is
progged to clip portions of the west and south central Friday
afternoon through early Saturday. An interrogation of BUFKIT
model soundings across the affected area during this period
reveal a somewhat shallow saturated DGZ and unimpressive mid
level lapse rates around 6 C/KM. Considering this and the the
fairly progressive nature of this system, overall snowfall
totals are forecast to be limited compared to some of our
neighbors. That being said, there is some decent agreement
between ensemble model families at some limited banding
potential across portions of the far southwest into the far
south central Friday afternoon and evening as weak 700-850mb FG
forcing slides along the ND/SD border, becoming briefly aligned
with moderate to strong Q vector convergence as it does so. If
this scenario comes to pass, some moderate snowfall rates would
be anticipated during this period, and thus enhancing the
overall snowfall accumulation. As of current forecast cycle, the
NBM 5.0 calibrated probability to exceed 2 inches of snowfall
through Saturday is from 50 to 80 percent south and west of the
Missouri River, and over an area along and south of I94 in south
central North Dakota. Notably, this area has sunk further to
the south and west over the past few forecast cycles as the NBM
catches up with its constituent ensemble families. Similarly,
the band of low to medium potential for 4 inches or more of snow
has sunk further south, and remain highest of the far southwest
into far south central North Dakota. If and where the limited
banding potential does set up Friday afternoon and evening, a
few locations in this same area could approach or even exceed 6
inches of snow overall, though this potential (10 to 30 percent)
may continue to be displaced further south into South Dakota
over the next few model runs. We will continue to evaluate this
system over the next few model runs.

After highs linger in the upper teens to mid 20s on Friday, a
much colder airmass is expected to settle over the region
through the weekend, reinforced by near northerly flow aloft.
Seasonably cold high temperatures broadly in the teens on
Saturday then drop even lower on Sunday, from the mid single
digits northwest to lower teens south. With this, overnight low
temperatures Saturday night and Sunday night are expected to
broadly sink in the single digits below zero. While winds
remains relatively light during this period, they will be
sufficient to drive wind chills into the teens to lower 20s
below zero both nights. The ensemble becomes increasingly
discordant beyond this point, though broadly speaking the surge
of arctic air is expected to cease as northwesterly flow is
reestablished. A weak shortwave sliding around a Hudson Bay Low
sometime Tuesday through Wednesday could invite another dusting
over snow over portions of the forecast area during this period,
though confidence in this remains somewhat shaky due to how
shallow this deviation is. Looking even further ahead, climate
analogues continue lean toward below normal temperatures through
the first week of December.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 605 AM CST Thu Nov 27 2025

Areas of dense fog and low stratus can be found across much of
western and central North Dakota this morning, with IFR to LIFT
ceilings and visibility found at KDIK, KJMS, and KXWA, while
KMOT and KJMS have improved to VFR conditions. Fog and low
stratus is expected to lift through the mid to late morning,
including over all terminals. Some patchy fog may linger over
portions of northwestern North Dakota through the afternoon.
Areas of fog and low stratus are expected to redevelop across
northwestern and central North Dakota this evening and
overnight, inducing MVFR ceilings ceilings and visibility a
KXWA and KBIS. Confidence is too low at other terminals at the
time of this update. This second round of fog and stratus is
expected to improve early to mid Friday morning. Snow will start
to move into southwestern North Dakota through the mid morning,
expanding to encompass much of western and south central North
Dakota beyond the end of the TAF period. With this update, have
added a Prob30 group for light snow at KDIK. Winds are generally
anticipated to remain light across the forecast area today,
variable this morning before reorganizing out of the southeast
overnight through early Friday.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM CST /9 AM MST/ this morning for
NDZ001-002-009>011-017>021-033>035-042-045>047-050.

&&

$$

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