NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 291149
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
549 AM CST Thu Jan 29 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Late night and early morning wind chills ranging from near 15
  below to 25 below zero through Friday morning.

- Below normal temps continue through Friday, then moderate
  slightly toward normal this weekend and next week.

- Besides non-impactful light snow showers or flurries at times
  through Friday, the next chance for widespread snow (20-50%)
  arrives Sunday afternoon into early Monday.

&&

.DISCUSSION...
Issued at 319 AM CST Thu Jan 29 2026

Temperatures/Wind Chills...

The arctic air will continue to bring well below normal temps to
the region today and Friday, as Canadian high pressure settles
into the Plains. Highs in the single digits to mid-teens are
expected, with lows tonight dropping back into the single digits
below zero to around zero in most spots, with a few double digit
below zero readings in the cold spots of north-central WI if we
can get the clouds to clear. Where the winds do not decouple and
become calm, wind chills will be approaching or briefly hitting
Cold Weather Advisory criteria both this morning and overnight
into Friday morning, generally between 15 below and 25 below.
With current temps/winds having everyone just shy of criteria or
not at criteria for long enough period or widespread enough (both
HREF and REFS showing under 20-40% probability of reaching
criteria), there are no plans for an advisory, but it will remain
quite cold for anyone venturing outside. Will continue to mention
in the HWO.

As the core of the arctic air shifts south/east this weekend,
temps will slowly moderate back toward normal. This will
especially be the case next week as flow turns more westerly.
Highs look to be mainly in the 20s for most of next week, with
lows in the single digits and teens. Wind chills should mainly
stay above zero as well.

Snow Chances/Trends...

As moist, northwest/north flow continues over Lake Superior, look
for very light lake effect snow shower/flurry activity to spread
across parts of north-central WI this morning with little (dusting
to a tenth or two) or no accumulation. Could be a lull in the
activity, along with a little sunshine for some (mainly in the
downslope areas) through the morning, then look for more clouds
and possible additional flurries or light snow showers later this
morning and afternoon as the northwest flow continues. Did expand
the light accumulations toward the Hwy 29 corridor, but no impacts
are expected.

Attention turns to the Lake Michigan, where a convergence lake
effect snow band will develop as winds turn north/northeast. CAMs
showing a dominate lake effect snow band organizing over the mid-
lake tonight. Question will become how far it can shift west
overnight into early Friday as winds attempt to shift more to the
northeast and an upper level trough drops south. A couple
negatives to consider for the band making it onshore are the
increasing ice coverage on/near the WI shoreline, which could
limit/impact the band as it heads westward, along with N/NNW winds
over land which will help the band stay over the water. One
unique scenario that could play out is the development of a
mesolow, which could pinwheel the main band toward the WI shore,
possibly bringing in a period of brief heavier snow, mainly south
of Sturgeon Bay. This would be the one scenario where a small area
near the lake would see some impactful snow (around an inch). For
now, will stick with 15-30% PoPs near the shore, with accumulations
under a half inch, which is supported by the NBM/HREF showing
under a 50% chance for a half inch.

The next chance for an area-wide light snow event arrives Sunday
afternoon into early Monday as a clipper systems swings across the
Great Lakes. Currently have 40-50% PoPs, but as with the last
clipper, imagine PoPs for a 6-hour period will creep up as we
approach the event. It will be another quick mover with limited
moisture, so expected under an inch of snow (LREF and NBM
probabilities of over an inch under 30% for most of the area,
slightly higher in Vilas Co. on the LREF). There could be just
enough snow to create some minor travel impacts for the Monday
morning commute.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 549 AM CST Thu Jan 29 2026

Area of MVFR ceilings will continue across portions of central and
northern WI this morning, with some flurries possible. VFR
conditions are expected elsewhere to start the day. Look for the
MVFR or low-end VFR clouds to expand across the area later this
morning and afternoon. Some flurries or light snow showers will be
possible with these low clouds, but should not have any impact on
flying conditions, except possibly some briefly lower visibilities
closer to the MI border. A lake effect snow band is expected over
Lake Michigan tonight into Friday morning. It is expected to
approach MTW, but it remains unclear if it will move far enough
west to bring lower flying conditions. Clouds look to scatter out
this evening and overnight. Northwest to north winds will stay
generally under 10 kts today into tonight.

&&

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

&&

$$

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