Forecast Discussion for GRB NWS Office
060
FXUS63 KGRB 301018
AFDGRB

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

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

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

- Lake-effect snow could bring around an inch of accumulation
  along the lakeshore this morning.

- 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 06Z TAF Issuance
Issued at 1056 PM CST Thu Jan 29 2026

Overall, expect SCT-BKN VFR cigs the rest of the night, with a
few flurries over northern WI as a surface trough drops across the
region.

On Friday, a lake effect snow band is expected to come onshore
near MTW in the morning, at least briefly, before dropping to the
south in the afternoon. Continue to frame out the most favored
time to see IFR conditions (vsby reductions). Confidence is still
on the lower side as some guidance still keeps bulk of the band
offshore, just grazing MTW. Otherwise, SCT-BKN VFR clouds in the
morning will trend toward BKN MVFR from the afternoon into the
evening. A few flurries may come out of the lower cloud deck as
well.

Light northwest winds shift north late tonight. Northerly winds
will then turn gusty for most of the day on Friday, especially at
MTW once the lake effect shifts by. Northwest winds will diminish
again on Friday evening.

&&

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

&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......JLA

NWS GRB Office Area Forecast Discussion