220
FXUS63 KGRB 151146
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
546 AM CST Thu Jan 15 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- There is a 60-90% chance for snowfall accumulations greater than
  2 inches across most of the area from this afternoon through
  Saturday. Snow-covered and slippery travel will occur at times.
  Also, there will also be breaks in the steadier snow through
  Saturday.

- Cold temperatures arrive late in the weekend and early next week,
  with wind chills as cold as 10 below to 30 below zero.

- A clipper system may bring light snow and the potential for
  hazardous travel Sunday, and then possibly again during the
  middle of next week.

&&

.DISCUSSION...
Issued at 312 AM CST Thu Jan 15 2026

500mb ridge across western North America will remain firmly in
place during the forecast period, while downstream trough over
eastern North America will result in periodic chances of light
snow along with below normal temperatures during most of the
period. As the upper trough deepens into the weekend, there
will be a prolong period for chances of light snow from this
afternoon through Saturday. As the pieces of energy rotate with
the mean flow of the upper trough, there will be certain periods
of higher chances of light snow, although figuring when and where
can be complicated by each model solution.

For today, skies will vary from mostly clear across central into
portions of northeast WI with mostly cloudy skies across the
north. The next clipper system will spread light snow (60-80%)
into north-central WI between 2 pm and 4 pm, and then across the
rest of the area by early evening in response to 850mb warm
advection. There is scenario across eastern Wisconsin where the
first round of light snow moves across the area through mid
evening, then there will be a break in the snow until later in the
night until main shortwave feature approaches the area. Have
trended lower in the chances of light snow later in the evening
across the east. Also, during the evening, bufkit soundings also
support the potential for freezing drizzle for a few hours across
central into north-central WI. Later tonight into Friday morning,
models depict shortwave energy moving across the forecast area.
There could be a band of steadier snow with lower visibilities
from central WI into the Fox Valley east to the lakeshore, which
could bring a higher impact for the Friday morning commute. There
could be a band of higher snowfall rates and lower visibilities
for a few hours. The chances of light snow continue Friday night
and Saturday as upper trough swings across Wisconsin. The greatest
focus for snow will be across the far north-central WI where snow
chances are 40-80%. The focus for Saturday will be across central
into northeast WI where snow chances are currently 40-70%.
Otherwise, the active pattern will continue with another chance of
light snow on Sunday (30-60%) and possibly during the middle of
next week.

After highs in the 20s to lower 30s on Friday, colder air returns
on Saturday, then temperatures bottom out on Monday. ECMWF
indicated 850mb temperatures of -28C to -30C which supports high
temperatures struggling to warm to around zero. The probability of
highs below 10 degrees were greater than 80%, with near 100% over
north-central WI. The probability of highs not reaching zero
ranged from 10% along the lakeshore to 70% in far north-central
WI. Wind chill readings of -10F to -30F are likely Monday morning
and Tuesday morning, resulting in frostbite on exposed skin in as
little as 20 minutes. Temperatures will moderate towards the
middle of next week, but still below normal. With the warmup will
need to watch for a clipper system thus the potential for some
light snow around the middle of next week.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 534 AM CST Thu Jan 15 2026

MVFR CIGS continue across the north early this morning which
should erode by late morning. The next round of light snow
will move into north-central WI between 18-22z and over the
rest of the area by 03z Fri. Low confidence in the start time of
the light snow due to model difference in how quick the atmosphere
will saturate. Periods of light snow will continue into Saturday
which will result in snow covered and slippery runways. CIGS
should drop into the MVFR and IFR category due to the light snow
and low clouds across the entire region tonight. On a side note,
air temperatures are expected to climb to near or a few degrees
above freezing on Saturday across east-central WI, with
temperatures falling below freezing Saturday night could create
slippery spots. After Saturday, there is another chance of light
snow on Sunday.


&&

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

&&

$$

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

NWS GRB Office Area Forecast Discussion