663
FXUS63 KGRB 081825
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1225 PM CST Mon Dec 8 2025

Updated aviation portion for 18Z TAF issuance

.KEY MESSAGES...

- A clipper system is expected to bring a swath of 1 to 3 inches
  of snow along and north of a line from Wausau to Green Bay to
  Manitowoc tonight. Lesser amounts are expected farther south.

- A more potent clipper system is expected to bring another round
  of snow to the area late Tuesday afternoon into Wednesday
  morning. This system is expected to produce 3-7 inches of snow
  over much of the forecast area. There is still some uncertainty
  in where the axis of heaviest snow will set up. A Winter Storm
  Watch has been issued for portions of the area from late Tuesday
  afternoon and evening into Wednesday morning.

- Temperatures will moderate some by the middle of the week, then
  turn colder again late in the week. Wind chills of -10 to -30
  are possible Friday night into early Saturday and again Saturday
  night into Sunday morning.

&&

.DISCUSSION...
Issued at 259 AM CST Mon Dec 8 2025

Short Term...Today...Tonight...and Tuesday

High pressure will push off to the east today, which will allow
winds to turn southerly as a clipper system approaches from the
west. Models suggest low clouds will develop in the late morning,
and there may be just enough saturation depth for some flurries
by afternoon. CAMs show that a north to south oriented lake-effect
band should stay out over Lake Michigan, though a few flurries
could impact the shoreline. The low pressure system will impact
the region tonight, and should bring a swath of 1 to 3 inches of
snow north of a Wausau to Green Bay to Manitowoc line. Recent
model runs have bumped up snow totals a few tenths of an inch
from previous runs. Gusty winds are expected across the region
tonight, with the potential for a few gale force gusts across the
nearshore areas, especially north of Sturgeon Bay.

Snow will taper off Tuesday morning from the first clipper system,
with a few hours of respite before the next clipper system
approaches fast on its heels, bringing another swath of snow to
the area Tuesday afternoon. The best moisture and dynamics will
not quite be in the area by Tuesday afternoon, with snowfall
amounts expected to mainly be below an inch during this period.

Long Term...Tuesday Night Through Sunday

The main focus for this period will be the clipper system expected
to bring an impactful snowfall to the region late Tuesday
afternoon into Wednesday morning, then the passage of an arctic
cold front that will bring bitter cold wind chills Friday into
next week.

For Tuesday night, potent clipper system expected to bring a swath
of moderate to heavy snow across portions of the area. A widespread
swath of 3-7 inches of snow is expected, however there is still
uncertainty in where the highest totals of 6+ inches would occur,
thus the Winter Storm Watch covered more counties than if there
was a convergence on location for the highest snowfall totals.
The NAM/ECMWF is further north while the Canadian/GFS are further
south. On the backside of the system, strong northerly winds
are expected to produce some blowing or drifting of the snow,
especially across eastern Wisconsin. Due to the ongoing light
snow and gusty winds, the watch was continued until 9 am
Wednesday morning for the Interstate/Highway 41 corridor east
to the lake.

High pressure builds into the region Wednesday night to allow for
temperatures tank. On Thursday, high pressure slides east across
the area while a clipper passes to the southwest. Attention then
turns to an arctic cold front that will move across the area on
Friday, bringing a chance of light snow. Arctic air is expected
to linger across the area Thursday through the weekend, with the
coldest air next weekend where wind chills of -10F to -30F are
possible at times.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1225 PM CST Mon Dec 8 2025

VFR conditions were the main flight category observed across the
region late this morning, with a few sites in central and north-
central WI reporting MVFR conditions at times due to passing
flurries. Anticipate these conditions will continue for the
remainder of the afternoon with intermittent flurries within the
lower cigs ahead of an approaching clipper system.

The quick-moving clipper system will bring accumulating snowfall,
reduced vsbys, and MVFR/IFR conditions to the area from west to
east late this evening into tonight. General arrival times at
CWA/AUW/RHI around 04z Tue, and around 05-07z Tue at the east-
central WI TAF sites. By early Tuesday morning, about 1-3 inches
of snow is forecast along and north of a Wausau to Appleton to
Manitowoc line. However, as the snow ends early Tuesday morning,
there are indications of the MVFR/IFR conditions sticking around
through the remainder of the TAF period with potential for
freezing drizzle to occur.

Southerly winds will increase this afternoon into this evening with
gusts to 15 to 20 kts. There still appears to be a period of LLWS
that will occur tonight with southwest winds up to 40 kts just
above the surface, before surface winds turn westerly by Tuesday
morning.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Tuesday afternoon through late Tuesday
night for WIZ018>021-030-031-035>037-045.

Winter Storm Watch from Tuesday evening through Wednesday
morning for WIZ022-038>040-048>050-074.
&&

$$

DISCUSSION.....Kurimski/Eckberg
AVIATION.......Kruk