265
FXUS63 KFGF 050537
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1137 PM CST Thu Dec 4 2025

.KEY MESSAGES...

- Areas of light freezing drizzle may lead to slick travel
  conditions through midnight tonight.

- Accumulating light snow may impact the early Friday morning
  commute within southeast North Dakota into west-central
  Minnesota.

- Clipper systems bring additional opportunities for winter
  impacts this weekend into next week, particularly around
  Tuesday and Wednesday.

&&

.UPDATE...
Issued at 905 PM CST Thu Dec 4 2025

Loss of ice development aloft and just enough saturated depth
in the -2C to -6C range is leading to a few areas of freezing
drizzle over parts of the Red River Valley in eastern ND and
north of Highway 2 in northwest MN (including detected light
icing on the KBDE ASOS sensor). In the same areas where these
reports are occurring precip types are alternating between
flurries and very light freezing drizzle, and duration/impacts
are more uncertain as a result.

At the NWS office at Grand Forks there is very light
accumulation on the windward side of elevated objects, but no
indications of accumulation on other surfaces yet. Where rates
are high enough slick travel may occur, so this is worth
monitoring and considering if traveling. The window for this
appears to be ahead of the approaching wave in western ND before
saturation aloft increases. For now I went ahead and added fzdz
mention to the forecast and issued an SPS, but held off on
issuing a Winter Weather Advisory for light icing. If it
looking like advisory impacts are likely I will reconsider.

UPDATE Issued at 630 PM CST Thu Dec 4 2025

There are still several areas of light snow in northwest MN on
the back side of the first mid level wave that are
transitioning east this evening. THe next mid level wave is
becoming organized upstream in western ND and this is lining up
well with 12Z HREF and shorter range CAMs/timing. Adjustments
were made to reflect coverage trends this evening/overnight,
with no changes to impacts/messaging from earlier discussion.

&&

.DISCUSSION...
Issued at 141 PM CST Thu Dec 4 2025

...Synopsis...

The Northern Plains and Upper Midwest will be generally in the
midst of northwest flow aloft in between broad upper troughing
centered near the Hudson Bay and upper ridging over the eastern
Pacific. Upper jet max on the crest of the Pacific upper trough
will help continually feed energy and moisture into the western
CONUS and CAN, at times phasing with shortwave troughing on the
western flanks of the Hudson Bay troughing. This allows several
shortwave troughs/clippers to traverse the Northern Plains and
Midwest as guided by a rather stagnate baroclinic zone draped
northwest to southeast across the Northern Plains into the
Midwest. This will be the case throughout the forecast period
ending into mid next week.

This active pattern will continue to bring periodic episodes of
snow/wintry precipitation, gusty winds, as well as variable
temperatures ranging from near average to below average. Each
clipper will bring its own potential for winter impacts, mainly
in the sub-advisory category, with the exception of Tuesday and
Wednesday. More details can be found below regarding early
potential impacts early Friday morning and Tuesday into
Wednesday.

Below average temperatures are most favored this weekend behind
a cold front that moves through during the day Friday. Sub-zero
temperatures are forecast, with wind chill values into the
negative 20s Saturday and Sunday.

...Potential Impacts to Early Friday Morning Commute...

The next clipper to impact the area comes across ND into MN late
tonight into Friday. Ensemble and high resolution guidance all
suggest deep saturation throughout the column, including within
an area of synoptic forcing mainly via vorticity advection,
lending credence in snow production. Steep lapse rates aloft
juxtaposed with saturation and forcing will allow for convective
elements to percolate within the area of snow as it traverses
generally west to east across southeast ND into west-central MN
early Friday morning.

While forcing is present, it isn`t overly strong. This will keep
overall snow amounts lower, with 25th-75th percentile
accumulation in the 0.5 to 2.5 inch range. Additionally, a lack
of surface pressure gradient and cold air advection will keep
winds relatively light during its passage. This wouldn`t
normally pose an impact, however, it does move through the I-94
corridor and Fargo-Moorhead metro area within the early Friday
morning commute hours between 4 AM and 8 AM.

Thus, this seemingly innocuous light snow accumulation may
impact unaware morning commuters. Decided to message this
potential for this particular reason.

...Tuesday and Wednesday Potential Impacts...

While there are several potential generally weak clipper systems
between Friday and Tuesday, ensemble guidance agrees in
Tuesday/Wednesday clipper carrying more strength and moisture,
thus greater potential for impacts. Ensembles still vary in
important synoptic evolutions to pin point impact potential and
types of weather hazards that lead to impacts. Despite this
variation, impacts from accumulating snow, gusty winds/blowing
snow, and even wintry precipitation that may result in icing
potential, all appear plausible.

Currently, the chance for advisory-type impacts from this
clipper sits at 40%, with warning-type impacts being around 10%.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1136 PM CST Thu Dec 4 2025

Widespread MVFR to IFR stratus remains in place over much of
eastern ND and northwest MN, with a pocket of VFR still near
KFAR early in the TAF period that should rapidly fill in based
on nearby obs. There have been reports of very light freezing
drizzle over parts of the region, but the transition (mainly
northeast ND and far northwest MN), but the transition to all
snow appears to be underway. The main area of accumulating snow
and vis reductions due to snow rates is in line to move over
southeast ND and west central MN through Friday morning. This
ends but stratus lingers at least through the afternoon, with
drier arctic air starting to arrive late afternoon and evening
in ND though this may not be enough to bring VFR to KGFK/KFAR
until after 06Z.

Winds are shifting to the north then northwest as the low
pressure tracks over southeast ND into MN while a cold front
drops south (already in the northern Red River Valley).

&&

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

&&

$$

UPDATE...DJR
DISCUSSION...CJ
AVIATION...DJR