433
FXUS63 KGRB 070438
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1038 PM CST Sat Dec 6 2025

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- For tonight, snow accumulations around 1" are expected from
  Wautoma to Manitowoc. Farther north, accumulations will be
  lower. Chances of light snow taper off over northern WI, except
  in Vilas County, where some lake-effect snow will develop.

- A clipper system is expected to bring a swath of 1 to 3 inches
  of snow to the northeast two-thirds of the forecast area area
  Monday night into early Tuesday morning.

- A more potent clipper system is expected to bring another round
  of snow to the area late Tuesday into early Wednesday. There is
  a 30-50% chance of 4+ inches of snow, though the location of the
  heaviest snowfall is still uncertain.

- Below normal temperatures continue through early next week, with
  moderating temperatures expected Tuesday/Wednesday, then
  turning colder again later in the week.

&&

.DISCUSSION...
Issued at 257 PM CST Sat Dec 6 2025

Low clouds and scattered flurries were observed across the region
this afternoon, except across the far north, where there was some
sunshine. Temperatures were much below normal, in the middle teens
to middle 20s.

Fast WNW flow aloft will continue through at least mid-week, with
a series of clipper-type systems moving through. The first system
arrives tonight, bringing a swatch of significant snow from Iowa
into northern IL. A southward shift in the system has resulted in
lower snowfall totals in the GRB forecast area. Will only carry
accumulations of around an inch in our southern tier of counties,
with lower amounts farther north. The snow is also expected to
depart by daybreak. Parts of northern Wisconsin will not see any
accumulation with this system, but developing cold NNW flow off
Lake Superior will support an inch or less of powdery accumulation
in northern Vilas County late tonight into Sunday morning.
Clearing skies will bring abundant sunshine on Sunday, but also
lead to cold temperatures Sunday night, with sub-zero low
temperatures expected west and north of the Fox Valley.

Additional Snow Chances through the middle of next week...The
next clipper approaches on Monday, with increasing south winds
leading to strong WAA during the day. There are differing opinions
on whether there will be enough saturation for some light snow
development with the WAA, but for now will keep a mainly dry
forecast. The low pressure system will impact the region Monday
night through early Tuesday, and should bring a swath of 1 to 2
inches of snow to the northeast two-thirds of the forecast area,
with perhaps 3 inches over northern Door County. The most
impactful clipper system arrives late Tuesday into Wednesday, with
strong upper level forcing with a short-wave/upper low and the
LFQ of a 120 knot jet streak. In addition, this low will have
remnant moisture from a Pacific Northwest atmospheric river to
work with. Current probabilistic forecasts show a 30-50% chance of
4+ inches of snow across the forecast area, though the axis of
the heaviest snowfall is still uncertain. Headlines are looking
more likely during this period.

Precipitation chances become a bit muddled later in the week, so
did not budge from the model blended pops. Temperature trends
seem a bit clearer. After a mid-week moderation in temperatures
(highs in the mid 20s to lower 30s), there is a decent signal for
a return to colder temperatures during the latter half of the
week.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1038 PM CST Sat Dec 6 2025

A mix of VFR/MVFR/IFR conditions late this evening as light snow
starts to fall across parts of central and east-central WI.

Light snow will continue overnight, and end early Sunday morning.
Reductions to MVFR/IFR cigs and vsbys will accompany the snow. Up
to an inch of accumulation is forecast, highest farthest south
(KMTW in the Green Bay forecast area). Most of northern WI will
miss the overnight snow, however some light lake- effect showers
are possible on Sunday at KRHI.

As the snow departs early Sunday morning, VFR conditions return,
with mostly clear skies through the remainder of Sunday TAF
period. The exception in far north-central WI, where NNW winds off
Lake Superior may keep some lower cloud around throughout Sunday.
Clouds return area wide Sunday night.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......KLJ