NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 192344
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
544 PM CST Fri Dec 19 2025

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Light snow possible late tonight into Saturday morning.
  Accumulations will largely be focused towards north-central
  Wisconsin, with a dusting possible across central and east-
  central Wisconsin.

- Westerly gales are expected late Saturday afternoon into
  Saturday evening.

&&

.DISCUSSION...
Issued at 226 PM CST Fri Dec 19 2025

Another clipper system is set to track through the northern Great
Lakes tonight through Saturday. Winds aloft will be on the
increase again through the lower to mid levels as a push of warmer
air arrives, but only a few gusts should mix down through around
midnight. As the cold air swings through with the main portion of
the clipper, fairly decent frontogenetic forcing should bring snow
into north-central Wisconsin. This feature is mainly focused
across the border along the Upper Peninsula, but cold air
advection over the rest of the region will likely suffice for at
least some flurries or light snow. Still, snow amounts around a
couple inches will largely be focused towards Vilas County, with
amounts tapering to around an inch by the time you get to a line
from Rhinelander to Iron Mountain, and lesser amounts further
south. Probabilistic guidance indicates areas south of a line from
Merrill to Marinette to Sturgeon Bay have less than a 20% chance
of exceeding an inch of snowfall, with less than a 10% chance of
exceeding 2 inches across much of north-central Wisconsin, save
for far northern Vilas County.

Next round of precipitation is then in the forecast for late Sunday
night into Monday evening. Although again precipitation amounts
will be light, this may yet be another period that bears watching
for mixed precipitation or freezing drizzle as a warm layer will
be in the area which may hamper ice production to a relatively
colder surface. Where the warmer air lines up as we get closer
will drive the precipitation type for this feature and the
impacts.

Temperatures for the period will see a couple swings through the
first few days of the forecast, with highs mainly in the teens
today and Sunday, but in the upper 20s to lower 30s on Saturday.
Then highs steady out for much of the middle of next week, with
highs mainly lingering in the upper 20s to middle 30s.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 543 PM CST Fri Dec 19 2025

Mid to high clouds will be overhead this evening. A few flurries
may occur from the mid clouds over central and north-central WI
this evening. Otherwise, a round of light snow is expected to
develop late tonight into Saturday morning as a cold front crosses
the region. Conditions could drop to MVFR with the snow, especially
across north-central Wisconsin. Snowfall amounts should generally
be light, with a dusting south of KRHI and an inch or two over
far northern WI. LLWS is expected late tonight into Saturday
morning as southwest winds increase to 30-40 kts just above the
lighter surface winds from the south. Conditions rapidly improve
behind the cold front Saturday afternoon as skies clear out. LLWS
will end, but west surface winds will gust to 25-30 kts at all
TAF sites.

&&

.MARINE...
Issued at 226 PM CST Fri Dec 19 2025

Strong southerly winds will build across Lake Michigan tonight,
with a few gale force gusts possible; however, a long enough
period of gales is not expected to upgrade to a Gale Warning. Gale
force winds are expected across all areas late Saturday afternoon
into Saturday evening with cold air advection bringing gusty
winds to the surface. The Gale Watch has been upgraded to a Gale
Warning for the waters during this period.

&&

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

&&

$$

DISCUSSION.....Kurimski
AVIATION.......JLA
MARINE.........Kurimski