Forecast Discussion for GRB NWS Office
308
FXUS63 KGRB 072111
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
311 PM CST Sun Dec 7 2025
Forecast discussion for routine afternoon forecast issuance
.KEY MESSAGES...
- A clipper system is expected to bring a swath of 1 to 3 inches
of snow along and north of a line from Wausau to Green Bay to
Manitowoc. Lesser amounts are expected farther south.
- A more potent clipper system is expected to bring another round
of snow to the area late Tuesday afternoon into Wednesday
morning. This system is expected to produce 3-6 inches of snow
over much of the forecast area. There is still some uncertainty
in where the axis of heaviest snow will set up.
- Temperatures will moderate some by the middle of the week, then
turn colder again late in the week. Wind chills of -10 to -25
are possible Friday night into early Saturday.
&&
.DISCUSSION...
Issued at 310 PM CST Sun Dec 7 2025
Low clouds and scattered flurries were observed across north
central WI this afternoon, but the clouds had eroded over the
past couple hours. High clouds were gradually increasing
elsewhere. Temperatures were much below normal, in the single
digits and teens.
Fast WNW flow aloft will continue through at least mid-week, with
a series of clipper-type systems moving through. The next clipper
approaches on Monday, with increasing south winds leading to
strong WAA during the day. Models suggest low clouds will develop
in the late morning, and there may be just enough saturation depth
for some flurries by afternoon. CAMs show that a north to south
oriented lake-effect band should stay out over Lake Michigan,
though a few flurries could impact the shoreline. The low pressure
system will impact the region Monday night, and should bring a
swath of 1 to 2 inches of snow north of a Wausau to Green Bay to
Manitowoc line, with perhaps up to 3 inches over northern Door
County.
The most impactful clipper system impacts the region from late
Tuesday afternoon through Wednesday morning, with strong upper
level forcing with a short-wave and coupled upper level jets,
and an intense low pressure system (985-990 mb). In addition,
this low will have remnant moisture from a Pacific Northwest
atmospheric river to work with. Current probabilistic forecasts
show a 50-80% chance of 4+ inches of snow across most of the
the forecast area. Far northern WI looks to be north of the main
QPF axis, and the far south could see a little rain mixed with the
snow, so the heaviest snow band will probably set up somewhere in
the middle. Winter Weather Advisories are looking likely during
this period, with a possibility of a narrow band of heavy snow.
Don`t see any big storms coming for the rest of the week, but
models are in agreement on the passage of a strong arctic cold
front during the Friday/Friday night time frame. This front could
bring wind chills of 10 below to 25 below zero Friday night into
Saturday morning. So, after mid-week "warm-up" (highs in the mid
20s to lower 30s), frigid temperatures will likely return late in
the week.
It will be a windy week, with low-end potential for southwest
gales Monday night and north gales on Wednesday, and higher-end
potential for northwest gales Friday into Friday night.
&&
.AVIATION...for 18Z TAF Issuance
Issued at 1134 AM CST Sun Dec 7 2025
Lake-enhanced low clouds (MVFR) covered north central and parts of
far northeast WI at issuance time, but any southward advancement
had ended. Will carry MVFR ceilings at RHI until around 21z, with
the expectation of clearing after that time. High/mid clouds will
increase overnight, and models strongly hint at some low cloud
(MVFR) development as south winds and associated WAA strengthen
late Monday morning. The forecast still looks on track for
accumulating snow Monday night, with the most significant amounts
(1-3 inches) occurring over the northeast half of the forecast
area.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kieckbusch
AVIATION.......Kieckbusch
NWS GRB Office Area Forecast Discussion