044
FXUS63 KGRB 161129
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
529 AM CST Sun Nov 16 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Mixed precip Monday night into Tuesday with snow accumulations
  (less than 1 inch, but monitoring for a narrow heavier band)
  could affect the Tuesday morning commute south of Hwy 29.

- Another weather maker brings precip chances (30-60%) Thursday
  into Friday.

- Temperatures return to near or slightly below normal this week.

&&

.DISCUSSION...
Issued at 339 AM CST Sun Nov 16 2025

Precip Chances: The majority of the Lake Superior lake effect
snow activity will stay in the U.P. today, but a stray flurry
could sneak to near the MI border and/or into northern Door Co.
this morning, along with some clouds. Otherwise, dry conditions
will prevail today into Monday as high pressure drifts into the
western Great Lakes.

The northern trend of the NBM/LREF has continued with the
shortwave trough and FGEN for the Monday night and Tuesday
system, as locations south of Hwy 29 look to get at least some
light mixed precip. Still some details to iron out regarding just
how far north the precip will get, whether it will be rain or snow
(and the change over time), and rain/snow amounts, especially as
we will be dealing with a FGEN band that could shift a little as
the event approaches and produce a narrow band of heavier snow.
NBM/LREF probabilities of 0.1"+ are up to 40-70% along and south
of Hwy 29, with 0.25"+ at 10-35%. Chances of 1+ inch of snow
running in the 15-30% range, highest just west of the Fox Valley
toward Marathon/Wood counties. Forecast soundings showing some
warm air near the surface for the precip to start as a rain/snow
mix. Then as the precip continues, better saturation occurs, and
the boundary layer cools during the night, a change over to mainly
snow is expected in central WI, with a rain/snow mix over east-
central WI. The precip could remain snow a little longer than what
is currently forecast in the stronger FGEN band, otherwise a
change over back to mix or plain rain is expected on Tuesday.
Canadian notably has the stronger FGEN a little further north,
which brings the heavier QPF band into the southern row or two of
counties. This will need to be monitored, as if it occurs and
encounters the colder air, a sneaky narrow band of snow could
develop. DGZ and best lift will be quite high (around 15,000 ft)
for much of the event, but a secondary lower area of lift does try
to form Tuesday morning. Some dry air will also need to be
overcome closer to the surface at the onset. Do expect a pretty
sharp gradient on the northern side of the precip as drier air
will be advecting in from the east/northeast as well. Snow plumes
are clustered around 0.5" in central WI, but some ensemble
members are in the 3-4" range (which likely accounts for the FGEN
band being further north). Will bump up snow a little, but keep
totals under an inch for now.

Once this system exits by Tuesday evening, dry conditions return
for Wednesday. Then as the upper flow turns to the southwest,
another low pressure system will track northeast into the Great
Lakes. Current temp profiles support mainly rain, with some
indications of some locally heavier rain will be possible, with
the LREF probabilities of 0.5+" approaching 40%. This would help
the worsening drought conditions, but don`t want to get hopes up
just yet.

Temperatures & Winds: CAA behind a cold front will drop temps
back to near normal today with highs ranging from the upper 30s
across north-central WI to the 40s across the rest of the area.
There will be a chill in the air today as northwest winds gust to
30 mph, dropping wind chills in the upper teens and 20s much of
the day. Lighter winds under 15 mph arrive for the majority of
next week. The seasonal temps will continue for most of the
week, with Thursday looking to be the warmest as a little shot of
WAA arrives ahead of the next weather maker. However, highs look
to stay mainly in the 40s, with probabilities of reaching 50
under 10% due to cloud cover.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 528 AM CST Sun Nov 16 2025

VFR conditions expected through the TAF period. A few low-end VFR
lake effect clouds will move across locations near the Michigan
border and Door County, mainly this morning. Otherwise, look for
plenty of clear skies with only a few daytime cumulus clouds and
some high clouds moving into central WI tonight.

Any ongoing LLWS will end early this morning as surface winds
increase, with gusts to 25 kts expected later this morning into
the early afternoon. Winds will decrease by sunset, with winds
under 10 kts tonight. Another period of marginal LLWS is possible
this evening as the surface winds decrease, but winds at 2000 ft
remain around 30 kts.

&&

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

&&

$$

DISCUSSION.....Bersch
AVIATION.......Bersch