677
FXUS63 KGRB 251959
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
159 PM CST Tue Nov 25 2025

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- A Winter Storm Warning has been issued for north-central
  Wisconsin from late tonight through early Thursday morning.
  Heavy snow of 6 to 12 inches is expected, with locally higher
  amounts in excess of 18 inches possible in the northwest corner
  of Vilas County.

- A Winter Weather Advisory has been issued for Lincoln and
  Langlade Counties for 3 to 5 inches of snow and hazardous travel
  conditions. The advisory has been expanded to include Marathon,
  Wood, Portage, northern Marinette and northern Oconto counties
  for 2 to 5 inches of snow and hazardous travel conditions.

- Strong northwest winds gusting 35 to 45 mph, locally up to 50
  mph, will develop on Wednesday. This will lead to blowing and
  drifting snow in the winter headline areas and difficult driving
  conditions for high profile vehicles across the entire area. A Wind
  Advisory has been issued for the rest of the area that does not
  have winter headlines for Wednesday.

- Another round of accumulating snow could impact travelers this
  weekend.

&&

.DISCUSSION...
Issued at 159 PM CST Tue Nov 25 2025

A low pressure system near the MN/IA border continues to deepen as
it heads east towards the western Great Lakes region. As this
low pressure tracks east and intensifies over Wisconsin tonight
through Wednesday, the focus of this forecast revolves around
highly impactful winter weather during one of the busiest travel
days of the year.

Short Term...Tonight through Wednesday Night

Precipitation Trends: The low will continue to intensify as it
tracks across north-central and far northeast WI tonight. Strong
QG and frontogenetical forcing will accompany the low, leading to
widespread precipitation across the area. The heaviest
precipitation is forecast to occur within the trowal airstream
over north-central WI. While thermal profiles look too warm for
snow initially in the evening, strong lift and heavy precipitation
rates combined with northeast winds advecting in colder air
should lead to a gradual transition from rain to snow starting
around mid evening over Vilas county and reaching the Lake
Michigan shoreline by mid to late morning Wednesday.

As the comma head precipitation sweeps across the area on
Wednesday in strong cold advection, precipitation will change to
snow at nearly all locations (except maybe the Door Peninsula) by
Wednesday morning. Nearly all locations will have the potential
to see 1-2 inches of snow on Wednesday. Most snowfall will
diminish in coverage and intensity by late Wednesday afternoon or
evening, becoming confined to the snowbelt of Vilas County.

Heavy Snow Potential: Thermodynamic profiles look quite favorable
for heavy snow accumulations from late tonight through about mid-
afternoon due to a large dendritic growth layer over north-central
Wisconsin. Lake enhancement looks quite favorable for Vilas
County from Wednesday morning through Wednesday night, with delta-
Ts around 14-17C, favorable wind trajectories, and equilibrium
levels increasing to around 10 kft. The heaviest synoptic QPF and
lake effect will occur in the snowbelt of Vilas County, where
there is a 60-90% chance of 10 inches or more of snow
accumulations. There is a signal (greater than 50% chance) of snow
reaching greater than 20 inches in the far northwest corner of
Vilas County. Consequently, Vilas County was upgraded to a Winter
Storm Warning.

Surrounding areas in Oneida, Forest, and Florence counties are
expected to see snowfall amounts ranging from about 3 to
8 inches, but uncertainty is higher there due to potential dry
slot issues. Given the strong winds, blowing and drifting snow,
and heavy travel weekend, the Warning continues for these
counties. Lincoln and Langlade counties are in an Advisory for 3
to 5 inches.

Even though lower snowfall amounts are expected in northern
Marinette, northern Oconto, Marathon, Wood, and Portage counties
the combination of 2 to 4 inches of snow along with very gusty
winds means either Winter Weather or Wind Advisory conditions (or
both) will be met. Given the main impact is winter weather will
lean towards a Winter Weather Advisory given the snow and blowing
snow potential.

Strong Winds: With strong subsidence in cold advection on the
back side of the low, strong northwest winds are likely to occur
late tonight through Wednesday. Gusts of 40-45 mph appear likely
(50-80% chance) across most of the area. Winds may be slightly
lower in the heavy snow area (30-40 mph). The strong winds
combined with heavy snow will make for very difficult travel over
north-central WI late tonight and Wednesday. Travel could become
impossible in Vilas county if the higher end snowfall amounts
materialize. Given the likelihood of strong winds will issue a
Wind Advisory for areas not already in any winter headlines as the
snowfall amounts do not rise to the level of Winter Weather
Advisory. Model soundings indicate there is the potential for some
gusts to approach High Wind Warning criteria; however, current
probabilities are not quite high enough to go with the higher
headline (up to 10 percent).

Long Term...Thursday through Monday

Strong low pressure will be departing the region over Quebec on
Thursday. Strong cold advection will be ongoing in an amplifying
pattern across North America. Lake effect snow showers will
likely continue into Thursday over north-central WI and perhaps
the northern Door Peninsula, with flurries possible over far
northeast WI outside of these areas. An additional 1-3 inches of
snow seems possible in Vilas County as delta-Ts remain in the mid
to upper teens with favorable wind trajectories. While light snow
will likely continue into Thursday night, dry air finally arrives
from the west over western Lake Superior, which should put an end
to any significant accumulations.

Gusty winds to 35 mph are likely on Thanksgiving Day, making for
a blustery holiday.

An amplifying long wave trough over the center of the continent
will lead to energy crossing the region on Saturday. This system
has trended deeper and faster, with a higher impact on the region
during the weekend after Thanksgiving and focused more on Saturday
and Saturday night with the highest impacts. Recent snowfall
probabilities have subsequently taken a noticeable turn upward;
with the probability for 2 inches or more of snow 50 to 80 percent
across the region with the highest probabilities across east-
central Wisconsin and the lakeshore. Yet another system could pass
close to the region by early next week.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1120 AM CST Tue Nov 25 2025

A deepening low pressure system will create precipitation
regionwide at times through Wednesday and poor flying conditions.
A widespread mix of LIFR and IFR conditions are present across
the region late this morning. Some improvement in conditions is
expected this afternoon, but IFR/MVFR visibilities are likely to
stick around.

Precipitation is expected to be widespread tonight. Rain will
change over to snow from west to east tonight into Wednesday
morning. A couple inches of snow may accumulate by the end of the
TAF period at Rhinelander. Several inches of accumulations are
likely north of Rhinelander.

Winds will be on increase as well late tonight, but moreso on
Wednesday when gusts are likely to reach up to 30 to 40 knots at
times by mid to late morning and last through the afternoon.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 9 PM this evening to 6 AM CST Thursday
for WIZ005.

Winter Storm Warning from midnight tonight to 6 PM CST Wednesday
for WIZ010>012.

Winter Weather Advisory from 9 AM to 6 PM CST Wednesday for
WIZ013-021.

Winter Weather Advisory from 3 AM to 6 PM CST Wednesday for
WIZ018-019-030-035-036.

Wind Advisory from 9 AM to 6 PM CST Wednesday for WIZ020-022-031-
037>040-045-048>050-073-074.
&&

$$

DISCUSSION.....Kurimski
AVIATION.......Kurimski

NWS GRB Office Area Forecast Discussion