387
FXUS63 KGRB 301719
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1119 AM CST Fri Jan 30 2026

Updated aviation portion for 18Z TAF issuance

.UPDATE...
Issued at 645 AM CST Fri Jan 30 2026

Radar trends show the main LES band remaining east of the
forecast area, and CAMs have caught on to this trend too, so have
lowered pops/QPF/snowfall considerably in our lakeshore counties
this morning. Will also be updating the MTW TAF to remove MVFR/IFR
vsbys this morning.

&&

.KEY MESSAGES...

- Wind chills still 10 below to 25 below early this morning, but
  temperatures trend toward normal this weekend into next week.

- A dusting to an inch of snow may create travel concerns from
  Sunday afternoon through Sunday night.

- A more impactful system may arrive for the end of the work week,
  with potential for accumulating snow, strong winds and gales on
  Lake Michigan.

&&

.DISCUSSION...
Issued at 417 AM CST Fri Jan 30 2026

Cold temperatures remained over the region early this morning,
with most places in the single digits above or below zero. A few
observation sites in north central WI had readings in the teens
below zero earlier, but cloud cover resulted in some moderation.
Though winds were on the light side, wind chills as cold as 10
below to 25 below zero were reported in spots.

A thermally-induced surface trough extended north to south along
Lake Michigan was providing focus for a long, narrow LES band
with numerous embedded circulations (meso-lows), which were
evident on radar. The best developed of these circulations should
shift south of the GRB forecast area, but several CAMs indicated
that another one would at least brush our lakeshore counties
south of Sturgeon Bay, with the greatest impacts expected over
eastern Manitowoc County. Current radar trends, the latest HRRR
and a prevailing N-NNE wind trajectory suggest a glancing blow, so
have lowered snowfall amounts to a half inch to an inch in most
areas. That being said, will have to watch meso-low development
carefully over the next couple hours, especially given strong
over-water instability (lake-850 mb delta-t`s of 22-24 C). Most of
the LES is expected to shift south of the forecast area by 18z.
Models also suggest a weak disturbance and associated area of
light snow impacting far NE WI this afternoon, including
Marinette and Door counties. NNW flow off Lake Superior should
also aid in the development of scattered lake-effect snow showers
in Vilas County this afternoon and evening.

Lingering light lake-effect snow showers or flurries should taper
off later tonight, with high pressure and upper ridging bringing
dry and milder conditions for most of the weekend. These milder
conditions should prevail through most of next work week.

A clipper system arrives Sunday afternoon and continues Sunday
night. This has the appearance of a high pop/low QPF event, so
have raised pops to likely over most of the forecast area. Most
places should see a half inch of snow, though there is a 20-40%
chance of an inch over mainly NC WI. Weak LES will develop over
far NC WI Monday morning as the system departs, but the snow
should be over in most areas before the morning commute.

Dry conditions are expected Monday afternoon and night, but a weak
inverted surface trough could bring a 20-30% of light snow to the
southwest part of the forecast area Tuesday into Tuesday night.

Perhaps the most interesting part of the forecast is the potential
for a strong and deepening clipper system moving through the area
later Thursday through Friday. These is decent model agreement
given it`s nearly a week away, and if the forecast holds, we will
likely see accumulating snow over most of the area, followed by
strong N-NW winds, possible gales on Lake Michigan and another
surge of arctic air as it departs.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1050 AM CST Fri Jan 30 2026

VFR conditions prevailed across much of the region this morning,
except across the far north where MVFR CIGS were reported in
some spots. For the afternoon and evening, low clouds are
expected to develop or spread southward with MVFR CIGS at
times. Along with the low clouds, there will be a chance of
snow showers across the far north and over far northeast WI
with a chance of flurries elsewhere. Clouds will beon the decrease
late tonight into Saturday morning. The next chance of light snow
(50-70%) is on Sunday afternoon and Sunday night. Most likely snowfall
amounts are from 1/2 to 1 inch.

&&

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

&&

$$

UPDATE.........Kieckbusch
DISCUSSION.....Kieckbusch
AVIATION.......Eckberg

NWS GRB Office Area Forecast Discussion