861
FXUS63 KFGF 060032
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
632 PM CST Fri Dec 5 2025

.KEY MESSAGES...

- Several light snow chances with below average temperatures
  through the weekend.

- A stronger system arrives on Tuesday, with a 60% chance of at
  least advisory level impacts.

&&

.UPDATE...
Issued at 632 PM CST Fri Dec 5 2025

An area of light snow/flurries that developed along/ahead of a
secondary cold front is tracking to the southeast. Most of this
is non accumulating/flurries, however there have been some
pockets with slightly higher rates where vis has dropped 2-5sm
and in those areas a dusting has been observed. This should
continue to progress to the southeast while additional flurries
may linger with stratus this evening. Adjustments were made to
reflect these trends.

&&

.DISCUSSION...
Issued at 123 PM CST Fri Dec 5 2025

...Synopsis...

General troughing over the eastern half of North America has kept
the Northern Plains locked into northwest flow for the past week.
Northwest flow is forecast to continue for the foreseeable future.
This will leave our FA in an active pattern, as waves ride the
baroclinic zone southeastward from the Canadian Rockies through the
High and Northern Plains. As each wave approaches, a period of warm
air advection will lead to warmer temperatures in the 20s to
occasionally 30s in the south. Then, as each wave passes
through, snow will occur over at least portions of the FA, with
colder/breezier conditions filtering in on the backside. This
rapid fire pattern of shortwaves continually repeats every
couple of days over the next week.

...Light Snow over the Weekend...

Several shortwaves over the weekend will bring light snow chances.
The first will pass through tonight into Saturday, as an area of low
pressure develops in the Plains of Montana, sliding southeast. The
best forcing with this system resides to our south. However the
broad nature of the synoptic forcing will promote light snow in the
southern FA during the day on Saturday. With arctic air helping keep
the storm track a bit more to our south, temperatures will
remain stuck in the single digits for highs for many locations
on Saturday and Sunday.

Another weak shortwave will propagate through on Monday. Again,
broad/weak synoptic forcing will foster light snow, with
minimal impacts.

...Tuesday Clipper System...

By late Monday, another area of low pressure will develop in the lee
of the Canadian Rockies in Alberta. This wave looks to be the
strongest in the parade of shortwaves. An interesting thing to
note this far out is the lack of spread in modeled scenarios.
Take the 12z GEFS for example. Every member develops an area of
surface low pressure in Alberta, tracking it southeastward
towards our FA by sometime during the day on Tuesday. The only
real differences are how fast the clipper is, which will impact
the exact timing of when precipitation starts/ends, along with
how far north the low tracks. For being 4 days out, it is pretty
remarkable that the differences in the systems track from
ensembles members is on the order of counties, not half of
states which seems to be more typical at this timeframe.

It is important to stress, however, that even though the general
evolution of this system seems fairly certain, the small differences
that remain will play a major role in determining the degree and
type of impacts at any one location, such as in your own backyard.
The strong warm air advection ahead of this system will likely crust
at least some of the snowpack across the southern FA, limiting its
blowability and increasing reliance on new snowfall to reduce
visibility. Warm temperatures at the surface and aloft will likely
complicate precipitation type as well for some locations, and impact
snow to liquid ratios elsewhere. Snowfall ratios will likely
not be consistent throughout the event either, as colder air
works in on the backside. Add on top that conceptually, systems
such as this one usually have the heaviest snow (associated with
warm air advection and frontogensis) displaced to the north of
where the strongest winds (associated with the largest surge of
cold air advection behind the southward draped cold front)
occur. EFI highlights this difference well, with both snow and
wind showing a shift of tails, but in drastically different
areas. Therefore, at this time it is too early to pinpoint where
which exact type of impacts will occur. This system will be one
to closely monitor over the weekend into early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 532 PM CST Fri Dec 5 2025

Widespread MVFR stratus is still in place across eastern ND and
northwest MN, with an area of light snow (brief vis reductions
to 2-6sm) tracking across the region. There are upstream trends
of clearing in Canada and north central ND on satellite/obs,
however additional pockets of MVFR stratus are developing just
to the north of the Red River Valley in Manitoba which would
continue to track south to KGFK/KFAR. Guidance supports all
locations becoming VFR tonight reflecting the areas of clearing
well, but not picking up well on the newer development.
Considering the current trends it is more likely that MVFR
lingers much of the night at KGFK/KFAR with VFR improvement not
favored until Saturday (after 12Z) when a drier northeast BL
flow is shown to develop.

Winds are still out of the north 10-14kt but should continue a
downward trend as surface high pressure builds south, then
eventually turns northeast Saturday as low pressure rebuilds to
the southwest. Another period of light snow may then develop to
the west and track east across southern ND/west central MN with
this low pressure system Saturday afternoon, but confidence is
lower in coverage/aviation impacts with that fast moving/
weaker wave.

&&

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

&&

$$

UPDATE...DJR
DISCUSSION...Rafferty
AVIATION...DJR