337
FXUS63 KGRB 302311
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
511 PM CST Fri Jan 30 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

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

- A more impactful system is anticipated for Thursday PM into
  Friday AM, with the potential for accumulating snow, gusty winds
  and possible gales on Lake Michigan.

&&

.DISCUSSION...
Issued at 224 PM CST Fri Jan 30 2026

For most of January, 500mb ridge across western North America
has dominated the weather pattern with downstream troughing
noted across eastern North America. This pattern has led to
warmer conditions across the western United States with cold
across the east. In matter fact, the 500mb trough will deepen
enough to drive the 850mb 0C isotherm all the way south to
Miami and Key West, Florida Sunday morning (GFS/ECMWF models).
Back in Wisconsin, for the month temperatures have been averaging
2 to 5 degrees below normal. Temperatures during the forecast
period are going to warm up to seasonable cold category, possibly
reaching the upper 20s later in the week.

There are two systems to contend with during the period. The first
system is expected to impact the area Sunday afternoon and Sunday
night. The latest trends are to slow the eastern progression of
the snow as it makes it into eastern WI. Some guidance doesn`t
have snow reaching Green Bay until mid-evening on Sunday.
Accumulations under an inch are expected across the entire area.
The NBM probabilities of an inch or greater of snow is only 10-25%
across central and north-central WI.

A strong clipper system is expected to move across the western
Great Lakes Thursday into Friday morning, with the greatest
impacts across northeast WI Thursday afternoon and evening at
the moment. Chance of snow are for now are set at 40-60%.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 511 PM CST Fri Jan 30 2026

A warm advection pattern with northerly winds will bring scattered
snow showers or flurries and a mix of MVFR/VFR ceilings to the
region this evening. The most persistent MVFR ceilings are
expected over north-central WI (KRHI) and eastern WI (KGRB, KATW,
KMTW) through the overnight hours. Snow showers should exit the
east-central sites early in the TAF period, while light snow and
flurries linger longer at KRHI. A brief period of LLWS is forecast
this evening as a 35 kts jet moves overhead at 2kft.

Drier air moving in from the west will lead to a clearing trend on
Saturday morning. Confidence in the timing of clearing is medium, as
northerly flow may keep MVFR ceilings in place longer than guidance
suggests, especially at KRHI. Mainly VFR conditions are expected for
all terminals by mid-afternoon with clear skies by Saturday evening.

Outlook...Light snow may bring MVFR/IFR conditions Sunday afternoon
and evening.

&&

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

&&

$$

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

NWS GRB Office Area Forecast Discussion