643
FXUS63 KFGF 232322
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
522 PM CST Tue Dec 23 2025

.KEY MESSAGES...

- Light wintry mix or snow Christmas Day into the evening, with
  a 30 percent chance for advisory level impacts

- A system moves through the region this weekend, potentially
  bringing winter impacts. There is a 10 percent chance for
  warning level impacts, mainly from blowing snow.

&&

.DISCUSSION...
Issued at 146 PM CST Tue Dec 23 2025

...Synopsis...

Deep upper troughing will continue over the eastern Pacific,
with broad upper ridging over the Southern Plains extending
into the Northern Plains. This will promote generally zonal to
flat southwesterly flow aloft over our region. Pacific sourced-
moisture will flow through the jet stream aloft over the
Northern Plains, as well as impulses of energy. Generally
flurries with some embedded bouts of lightly accumulating snow
(less than 1 inch) will remain possible today and Wednesday.

One such piece of energy/moisture comes Thursday/Christmas Day.
This will bring wintry precipitation to the region, including
the chance for light ice accretion and snow accumulation. Much
uncertainty still exists with this system. More details below.

Toward this weekend, ensemble guidance suggests a break in the
Pacific trough, or at least the northern portion of it,
allowing it to traverse eastward into the central CONUS and
central CAN. This will bring more consolidated forcing into the
Northern Plains and Upper Midwest, as well as moisture. Much
uncertainty extends into this potential as well. More details
below.

Temperatures are forecast to be generally near average, with
potential for above average temperatures Thursday ahead of the
approaching system. Confidence, however, is low to medium in
temperature forecast, mainly due to unknowns about cloud cover
and strength of subsequent waves mentioned above.

...Wintry mix Christmas Day / night ...

As a shortwave trough embedded within the upper ridging /
quasi-zonal flow traverses the region Thursday, warm
temperatures will work its way into the Dakotas. This includes
temperatures above freezing aloft nosing their way into the
region ahead of the wave. Ensemble guidance strongly suggests
this will coincide with light precipitation, driving the
potential for wintry mix, including freezing rain and/or sleet
in addition to snow. Most guidance currently suggests
accumulations of snow and ice will be light (generally under 4
inches and 0.1", respectively). However, available
deterministic guidance does hint at some transient mesoscale
forcing being present, lowering confidence in
amounts/accumulations. Additionally, ensemble spread in
synoptic evolution of this wave lowers confidence in location of
impacts.

Despite lighter amounts, potential for travel impacts on a
potentially busier than average travel holiday period means it
wouldn`t take much accumulation to result in impacts, especially
from icing. Thus, there is a 30% chance for advisory- type
impacts.

...Potential winter impacts this weekend...

Ensemble guidance is starting to agree in at least some
development of a stronger wave emanating out of the broader
Pacific trough, deepening into the Great Lakes region, this
weekend. While spread is high in synoptic evolution like track
and strength of the eventual low pressure system, ensemble
signals like ENS EFI is highlighting the potential for increased
winds into our region, particularly Sunday.

Should this system deposit as little as 2 inches of snow with
high winds over 35 mph, blowing snow impacts can be
anticipated, including potential for blizzard conditions. This
is a plausible scenario that could happen, however just as
plausible is a scenario that results in little to no snow, with
lesser winds. This would mitigate winter impacts during another
potentially higher than average travel holiday period.

While the envelope of potential impacts is large, there is
still much uncertainty that lowers confidence in potential
impacts. Thus, there is currently a 10% chance for warning-
level impacts.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 518 PM CST Tue Dec 23 2025

Pockets of MVFR ceilings may arise at any TAF site, but
predominately VFR conditions can be expected through 06z. After
06z, ceilings should begin to lower in eastern North Dakota to
MVFR, although it is unclear how far east this gets so it may
not make it to TVF. The bulk of guidance keeps this west of
BJI, so expect continued VFR conditions there. Fog may also
develop in eastern North Dakota, driving down visibilities,
however the probability for this is low right now, but it is
something to monitor as a possibility considering the weak
winds.

As we progress after 12z, ceilings/fog should lift but it is
uncertain if ceilings will remain MVFR or become VFR. At a
minimum, expect a ceiling to continue to prevail for the
afternoon with a general range of ceiling between 2000-4000ft.
Winds will eventually shift to northerly towards the end of the
TAF period west of BJI but remain sustained generally below 15
knots. No other aviation impacts are expected to develop.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

DISCUSSION...CJ
AVIATION...Perroux