NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 311734
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1134 AM CST Sat Jan 31 2026

Updated aviation portion for 18Z TAF issuance

.KEY MESSAGES...

- Light snow is forecast to move across the region Sunday
  afternoon and Sunday night. Accumulations of a half inch (60%
  chance) to one inch (10-30% chance) are expected. Slippery
  travel conditions are expected, which may extend into the Monday
  morning commute.

- A potent clipper system may impact the area next Thursday and Friday.
  While significant timing and track uncertainties remain, this
  system has the potential to bring accumulating snow and gusty
  winds.

- Temperatures will be moderating this weekend. Highs in the 20s
  will be common for much of next week.

&&

.DISCUSSION...
Issued at 342 AM CST Sat Jan 31 2026

Aside from some lake-enhanced flurries or light snow showers in
north central WI, precipitation has ended in most areas early
this morning. Widespread low clouds persisted across the northwest
and eastern parts of the forecast area, with a large wedge of
clearing in between. Early morning temperatures were in the upper
single digits and teens.

High pressure will build into the region today, and this should
result in a gradual clearing trend this morning. With the arctic
air mass finally dislodged, highs are expected to warm into the
upper teens to middle 20s regionwide. Clear skies and light winds
persist into tonight, though a light south breeze and increasing
boundary layer winds should keep temperatures from plummeting
too far. Lows are expected to be mainly in the single digits
above zero, though a couple cold spots could briefly drop a few
degrees below zero.

Attention then turns to a clipper system arriving Sunday. Strong
shortwave energy over the northern Plains tonight will shear apart
partially as it digs into the western Great Lakes Sunday
afternoon and night. While large-scale forcing appears modest,
precipitable water values of 130-140 percent of normal will
support a band of light snow. A 60 percent chance of snow exists
for central and north-central Wisconsin Sunday afternoon,
spreading to eastern Wisconsin Sunday evening. Most locations
should receive around a half inch of snow, though amounts could
approach an inch in parts of northern WI. The snow should end
by Monday morning, though slippery stretches could linger into the
morning commute.

A brief period of high pressure will bring dry conditions late
Monday through Wednesday as the upper-level pattern re-amplifies.
An upper ridge will then strengthen over the western U.S. while a
mean trough reinforces itself over the East. This setup will pave
the way for a potentially more significant clipper system
Thursday into Friday. Model guidance indicates an intensifying
low pressure system crossing the Great Lakes, though large
spreads in multi-ensemble blends lead to low confidence in the
exact track and timing. Given the potential for strong dynamics,
this system will need to be monitored for both accumulating snow
and strong wind impacts. Current probabilities for snowfall
greater than 1 inch are highest across far northern Wisconsin at
40-60 percent. There is low-end potential (20-40 percent chance)
of gale force gusts near Deaths Door as the system departs.

Milder temperatures will persist through most of the period, with
highs reaching the 20s on most days, and perhaps even into the
lower 30s in C/EC WI ahead of the late week clipper system.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1130 AM CST Sat Jan 31 2026

MVFR CIGS and a few flurries at KGRB/KATW/KMTW should end between
20-21z, with another area of MVFR CIGS at Vilas County airports
should also end by 21z. Northwest winds will diminish and also
back southwest late this evening. Clouds will be on the increase
through the night as the next system approaches from the west.
There is some concern that IFR CIGS could develop at KRHI after
06z due to inversion in the low levels near the inversion, plus
upslope flow in the far north. Confidence is low this will happen.
Snow will move into central and north-central WI early to mid
afternoon on Sunday, then slowly work east into far eastern
WI where snow may not arrive until early to mid evening. Most
locations should see under an inch.

&&

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

&&

$$

DISCUSSION.....MPC/Kieckbusch
AVIATION.......Eckberg