847
FXUS63 KGRB 281017
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
417 AM CST Sun Dec 28 2025

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Areas of fog expected today. Patchy freezing fog or freezing
  drizzle may create slippery conditions on untreated surfaces in
  northern Wisconsin this morning.

- Winter Storm Warnings are in effect for the entire forecast
  area, for heavy snow, strong winds and considerable blowing and
  drifting snow, from late this afternoon through Monday.
  Treacherous travel conditions are likely, and some tree damage
  and power outages are possible.

- Strong northwest winds gusting to 35 to 50 mph inland, and gale
  or storm force gusts to 45 to 50 knots on Lake Michigan, are
  anticipated from late tonight through Monday evening.

- A surge of below normal temperatures is likely towards the New
  Year`s time frame. Wind chills as cold as 10 to 20 below zero
  are possible Thursday morning and Friday morning.

&&

.DISCUSSION...
Issued at 416 AM CST Sun Dec 28 2025

Changes to Winter Storm Warning Headlines: Winter Storm Warnings
remain in effect for the entire forecast area, but some minor
changes to snowfall amounts and impacts have been made. In
general, snowfall amounts have come up a little bit and more
emphasis on potential power outages has been added, especially
in northern WI, where the heaviest snowfall will occur. Start
times have also been moved up a few hours in some places, as the
changeover to snow is expected to occur a bit quicker than
previously thought. Some minor adjustments to end times have also
been made, mainly to line up with decreasing trends in winds and
blowing snow.

Areas of fog covered the forecast area this morning, but rising
vsbys in central WI allowed for a cancellation of the Dense Fog
Advisory. Minor travel concerns were occurring over north central
WI, where air and road temperatures were hovering near freezing,
leading to potential for patchy icing due to freezing fog or
light freezing drizzle. Have covered the travel concerns with a
Special Weather Statement.

Low pressure was developing in eastern KS early this morning, as
a potent short-wave and jet streak ejected out of the base of the
deep Northern Plains upper trough. This low will deepen rapidly
as it moves through southern Lake Michigan this afternoon and
tracks toward southeast Ontario late tonight. Models continue to
trend higher with QPF/snowfall, so have bumped up snowfall totals
an inch or two, especially over our western and northern counties.
Strong winds gusting to 35 to 50 mph will produce considerable
blowing and drifting snow, and high-end gale to storm force gusts
are likely on Lake Michigan. Expecting 12 to 16 inches of snow
over parts of Vilas County (aided by lake-effect), 7 to 11 inches
across the rest of northern WI, and 4 to 7 inches farther south.
The combination of heavy snow accumulations and winds will likely
cause some tree damage and power outages, most notably over
northern WI and Door County. Most of the accumulating snow will
taper off late tonight into Monday morning, but winds are not
expected to decrease much until later in the day or evening, so
blowing and drifting snow will likely continue. Treacherous
travel conditions are likely through the event, but especially
tonight.

A clipper system passes north of the region Tuesday afternoon and
night, bringing a chance of snow followed by a surge of arctic
air for the New Year. This will bring renewed chances for lake-
effect snow in north central WI, as well as wind chills as low as
10 to 20 below zero later in the work week.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 935 PM CST Sat Dec 27 2025

Poor flying conditions are expected through the TAF period. IFR/LIFR
are already widespread across the region as low status and areas of
fog continue to impact the region. Conditions will further
deteriorate overnight as cigs lower to 100-300ft across most of the
region. Areas of dense fog area with vsbys under 1/4SM are expected
to expand tonight, mainly across central and northern WI.

Don`t expect much improvement in flying conditions Sunday as IFR/LIFR
status and areas of fog will linger through the morning. A potent
low pressure system will bring a mix of rain and snow to the region
Sunday afternoon with a transitions to mainly snow expected Sunday
evening as a cold front sweeps across the region. Within the
heaviest snow showers IFR vsbys will be possible.

Behind the cold front winds will shift to the northwest and increase
late Sunday into Monday. Gusts of 35-50 mph will be possible early
Monday morning.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 3 PM this afternoon to 3 PM CST Monday
for WIZ005.

Winter Storm Warning from 3 PM this afternoon to noon CST Monday
for WIZ010-018-030-035-036.

Winter Storm Warning from 6 PM this evening to 3 PM CST Monday
for WIZ011>013.

Winter Storm Warning from 6 PM this evening to noon CST Monday
for WIZ019>021-031-037-045.

Winter Storm Warning from midnight tonight to 6 PM CST Monday
for WIZ022-040-050.

Winter Storm Warning from 9 PM this evening to 3 PM CST Monday
for WIZ038-039-048-049-073-074.
&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......GK

NWS GRB Office Area Forecast Discussion