NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 171148
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
548 AM CST Sat Jan 17 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- The chances of snow showers continue today into this evening,
  with additional accumulations under an inch for most, except for
  1-2 inches in Vilas County.

- Heavier snow showers are possible from Marinette and Oconto
  counties southward to the Fox Valley and east to the lakeshore
  late this afternoon and early this evening. Motorists may
  encounter lower visibilities while there may be brief period
  of snowfall rates of 1" per hour.

- Bitter cold arrives this weekend into early next week, with a
  20-80% Monday morning and 60-100% chance of wind chills colder
  than -20F.

- A clipper system is expected to bring 0.5 to 1.5 inches of snow
  Sunday into Sunday night. Behind this clipper, strong northwest
  will are expected late Sunday night into Monday, creating areas
  of blowing and drifting snow. On the Bay of Green Bay and Lake
  Winnebago, near whiteout conditions will be possible.

- A clipper system will bring another chance of snow (30-50%)
  Tuesday night into Wednesday with another clipper system
  possible towards next weekend.

&&

.DISCUSSION...
Issued at 345 AM CST Sat Jan 17 2026

The persistent upper trough across the western Great Lakes will
finally shift east away from the area today into tonight. This
will bring an end to the snow shower activity for most of the area
later this afternoon or evening. The only exception will be
across the far north where light snow lingers into the overnight
hours. Additional snow accumulations should be under an inch,
except for locally higher amounts across northwest Vilas County.
There is one area to watch this afternoon into early this evening
is across northeast WI, from Marinette and Oconto counties
southward through the Fox Valley east to the lakeshore Several
models are depicting snow shower activity breaking out along a
surface through that drops southward across the area. Bufkit
soundings indicated steep low level lapse rates. It is possible
that heavier snow showers will break out along this boundary with
lower visibilities and snowfall rates to around an inch per hour.

Attention then turns to the next clipper that sweeps across the
area Sunday into Sunday night. The chances of light snow are
set at 60-90% with snowfall amounts between 0.5 and 1.5 inches
expected for most. Snowfall totals will be higher across the
far north where lake effect snow showers will linger into Monday.
Behind the clipper system, strong northwest winds will develop
with gusts of 30 to 45 mph with the highest gusts over Door
County. The snow on Sunday will be powdery, thus areas of blowing
and drifting snow will develop Sunday night and linger into
Monday. On the Bay of Green Bay and Lake Winnebago, near whiteout
conditions will be possible. The winds should subside Monday
afternoon.

The main story next week will be the bitter cold from Sunday
night through the end of the work week as well below normal
temperatures will continue into the weekend. The probabilities of
wind chill readings of -20F on Monday morning range from 10-20%
across Door County to 60-90% along the Interstate 39 and Highway
51 corridor in central and north-central WI. The probabilities on
Tuesday increase to to 60-80% along the lakeshore to near 100%
across north-central WI. On a side note, the chances of reaching
-35F Tuesday morning is 20-30% across central and north-central
 WI. The cold will continue into next weekend, with the warmest
 day being Wednesday with highs across from 10 to 20 degrees.
 Beyond the forecast period, the Climate Prediction Center 6-10
 day temperature outlook is calling for greater chances of below
 normal temperatures to continue. There is a fairly potent clipper
 system for Tuesday night into Wednesday, with the snow chances
 increased to 30-50% for now. There continues to be a lot of
 spread in the storm track of the system. Wherever the track ends
 up, this system could bring several inches of snow.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 530 AM CST Sat Jan 17 2026

Scattered snow showers or flurries will continue today into
this evening across much of the area, except across the
far north where light snow will linger overnight. CIGS
early this morning vary from VFR to MVFR as pockets of the low
clouds cleared out. Based on forecast soundings, the low clouds
in the MVFR category should reform for a few hours later this
morning where the low clouds cleared. The CIGS should then rise
into the VFR category this afternoon into the evening. For the
KGRB/KATW/KMTW TAF sites, watching a period from 22z Saturday to
03z Sunday for scattered snow showers to push southward across the
area. VSBYs in the snow showers could drop to 1-2 miles for a
brief period of time and produce up to a half inch of snow in
a short period of time.

Looking ahead, another round of light snow is expected from late
Sunday morning into Sunday night, with snow lingering across the
north into Monday. Outside the far north, expected snowfall
amounts should range from 0.5 to 1.5 inches. The bigger story
will be the gusty northwest winds developing later Sunday night
and continue into Monday afternoon with gusts of 25 to 35 knots.
The strong winds combined with the powdery snow will cause areas
of blowing and drifting snow that will impact airport snow removal
operations.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST today for WIZ005.
&&

$$

DISCUSSION.....Eckberg
AVIATION.......Eckberg