486
FXUS63 KGRB 302016
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
216 PM CST Tue Dec 30 2025

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- A clipper system brings a round of fluffy snow through this
  evening. An inch or less is likely for most, with 1 to 2 inches
  expected in the Fox Valley, bayshore and lakeshore areas as well
  as across the lake effect snow belt in north-central Wisconsin.
  Minor travel concerns are expected.

- An arctic cold front will bring additional light snow on
  Wednesday, with a dusting to a half inch anticipated in most
  areas. A couple inches of snow will be possible in Vilas County
  due to lake-effect.

- Wind chills as cold as 15 to 25 below zero are possible New
  Years Eve night into the morning on New Years Day.

&&

.DISCUSSION...
Issued at 210 PM CST Tue Dec 30 2025

First Round of Snow: A fast moving Clipper system is currently
bringing a swath of light snow and flurries to the region late
this afternoon. Although moisture is meager, snow ratios are
fairly high (upper teens) with fairly good dynamics in the form of
a mid level PV anomaly and left-front quad of a 110 knot upper
level jet. The high snow ratios and dynamics should lend
themselves to most areas getting around a half inch of snow, with
the Fox Valley, bayshore and lakeshore areas could get 1 to 2
inches. This will produce slick roads, especially in eastern
Wisconsin, for the evening commute.

Arctic Cold Front Snow: An arctic cold front will move into
northern Wisconsin late tonight, then drop south through the rest
of the region during the day on Wednesday. As this occurs,
conditions will become more favorable for lake-effect snow
(northwest winds and increasing instability over western Lake
Superior with delta T values around 20) in north-central
Wisconsin, with accumulations of 1 to 3 inches possible in Vilas
County. Despite the arrival of a dry arctic air mass, will keep
POPs higher than NBM (30-50%) given fairly strong dynamics with
the frontal passage, increasing frontogenesis, a mid-level short-
wave and the left-front quad of a 135 kt jet streak. Outside of
the lake-effect region, only expecting a dusting to a half inch
of powder in most areas.

Brief Period of Cold: A fairly strong push of cold air arrives in
the wake of the arctic front, with 800 mb temperatures dropping
to 18 to 23 below zero Celsius across the region later Wednesday
into Wednesday night. The combination of surface temperatures
falling into the single digits below zero (except near Lake
Michigan) and persistent northwest winds will result in wind
chills of 15 to 25 below zero late Wednesday night into Thursday
morning. These cold temperatures would likely impact any
activities late New Years Eve into the morning hours of New Years
Day. Cold Weather Advisories may eventually be needed for roughly
the northwest half of the forecast area. Some moderation in
temperatures is expected Thursday into Thursday night as incoming
cloud cover prevents temperatures from tanking overnight, which
will mean wind chill values will only fall to around 10 below zero
across central and north-central Wisconsin Thursday night into
Friday morning.

Rest of the Forecast: No significant precipitation events are
expected for the rest of the extended forecast period. After the
brief shot of arctic air, a gradual moderate in temperatures is
expected, with highs reaching the 20s by Sunday/Monday.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1133 AM CST Tue Dec 30 2025

VFR cigs were ubiquitous across the region late this morning, with
some MVFR cigs across northern Door County. Upstream, an incoming
Alberta Clipper was bringing an area of light snow and MVFR cigs
across northwest Wisconsin.

Light snow will overspread the region this afternoon, with mainly
MVFR ceilings/vsbys. Potentially more significant snow should
impact the region from mid-afternoon through early evening, with
periods of IFR vsbys expected. The snow should taper off from west
to east in the evening, though some lake-effect snow could
persist in far NC WI. Additional snow is expected on Wednesday as
an Arctic cold front sinks south through the region.

Winds will be from the W-NW with speeds of 10 knots or less
through tonight. Winds then increase to 10 to 20 knots with the
Arctic front Wednesday from the NW.

&&

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

&&

$$

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

NWS GRB Office Area Forecast Discussion