NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 040427
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1027 PM CST Sat Jan 3 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- An impactful system will bring snow, sleet, freezing rain and
  freezing drizzle late Sunday afternoon through early Monday
  morning. The greatest snow accumulations will occur across north
  central and northeast WI, but minor icing could occur regionwide.
  Hazardous travel conditions are anticipated, and may linger
  into the Monday morning commute.

- Warmer temperatures are expected next week, with a wintry mix
  of rain, freezing rain and snow possible with systems moving
  through Tuesday and again late in the week.

&&

.DISCUSSION...
Issued at 321 PM CST Sat Jan 3 2026

A short-wave brought light snow to the region today, but the snow
was gradually decreasing and pulling out of northeast WI late this
afternoon. Some breaks in the cloud cover were noted over western
WI. Temperatures were still quite cold, with most locations
reporting middle teens to lower 20s.

Surface high pressure will build into the region tonight and
linger into Sunday morning. Partial clearing is expected, which
should allow temperatures to drop into the single digits above and
below zero, except near Lake Michigan, where readings should
remain near 10 degrees. There is potential for some light fog
in NC/C WI late tonight.

Clouds will increase Sunday morning, as WAA increases ahead of an
approaching Alberta Clipper. This system is quite dynamic, with
strong forcing associated with a short-wave trough, WAA on the
nose of 35-45 knot low-level jet, upper divergence with a coupled
upper level jet and bands of intense FGEN impact the region late
Sunday afternoon and evening. Models are now pulling more warm air
aloft into the region, leading to more sleet and freezing rain
across the southwest half of the forecast area during the main
period of precipitation. Still expecting mainly snow over the far
north and northeast WI, where accumulations of 2 to 5 inches are
anticipated, though totals drop off quickly due to the wintry mix
along and south of Hwy 29. An additional period of freezing
precipitation occurs as the main precipitation band exits in the
late evening and overnight. A loss of ice crystals in the
saturated layer will likely lead to widespread freezing drizzle,
which should diminish later Sunday night into early Monday
morning. Total ice accumulations for the event should range a from
a couple hundredths in far northeast WI to around a tenth of an
inch in central WI. A Winter Weather Advisory will eventually be
needed for the forecast area, but given the recent trend of more
warm air aloft and more uncertainty in precip type and ice/snow
accumulations, will follow the consensus of surrounding offices
and hold off for now. Those with travel plans late Sunday
afternoon and Sunday night should expect hazardous conditions,
which may linger into the Monday morning commute.

There will be additional opportunities for mixed precip next
week, especially on Tuesday/Tuesday night and Friday/Saturday.
Precipitation type will be an issue as warmer air arrives and
highs surge into the 30s during the days, but fall into the 20s at
night. Additionally, the ground/roads may still be cold following
the recent stretch of cold weather, which could lead to locally
icy conditions even if temperatures are slightly above freezing.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1027 PM CST Sat Jan 3 2026

Good flying conditions are expected for most of the region under
a broad stratus deck that remains largely VFR. The only exception
will be across far north-central Wisconsin, where intermittent low
clouds have kept a low MVFR ceiling in place, impacting mainly
RHI.

Good flying conditions are expected for most of the day Sunday as
well before wintry weather arrives in the late afternoon and
evening. A mix of precipitation will accompany this system, along
with reduced visibility and quickly falling ceilings down to IFR
across portions of central and north-central. Freezing
precipitation will not be out of the question, especially later in
the evening so icing will become a concern for portions of Sunday
night.

&&

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

&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......Uhlmann