976
FXUS63 KGRB 130000
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
600 PM CST Mon Jan 12 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- A light mix of freezing rain. sleet and snow will result in
  hazardous travel across north central and northeast Wisconsin
  late tonight into Tuesday morning. Icy conditions will impact
  the Tuesday morning commute in the Northwoods.

- Accumulating lake-effect snow may cause additional travel
  concerns in far north central Wisconsin Tuesday night into
  Wednesday.

- Additional chances for snow arrive Thursday night into Friday
  and linger through the weekend.

- Mild temperatures occur prevail early this week, with a return
  to colder conditions from mid-week through the weekend.

&&

.DISCUSSION...
Issued at 312 PM CST Mon Jan 12 2026

Partly sunny skies and mild conditions were observed across the
forecast area this afternoon, with temperatures in the middle 30s
to middle 40s. Looking upstream, a 150+ knot upper level jet
over southern Canada was taking aim on the western Great Lakes,
with a strong clipper low pressure system developing northwest of
Lake Winnipeg.

The strong clipper system will pass well to our north (through
northern Lake Superior) late tonight into Tuesday. Moisture is
limited with this system, but strong forcing associated with a
short-wave trough, LFQ of an upper jet, WAA on the nose of a 30-40
kt LLJ and FGEN will produce light precipitation across mainly
northern WI late tonight into early Tuesday. A strong warm layer
aloft will be in place at onset, leading to at least a brief
period of freezing rain across NC/NE WI late tonight. The warm
layer aloft weakens due to wet-bulbing and dynamic cooling a few
hours after onset, leading to more of a sleet/snow mix into early
Tuesday morning. A light glaze of ice will coat the roads over the
Northwoods, leading to hazardous conditions overnight and into the
morning commute. Have issued a Winter Weather Advisory north of a
line from Merrill to Marinette starting at 08z/Tue and ending at
15z/Tue, when the mixed precipitation is expected to either taper
off or switch over to rain/drizzle. It is possible that the
advisory may need to be extended another row of counties to the
south. A mix of light rain and snow is expected across mainly
north central WI Tuesday afternoon.

A strong cold front moves through the region Tuesday night, bring
gusty northwest to north winds, widespread light snow or flurries
and colder temperatures. Accumulating lake-effect snow is
expected over north central WI Tuesday night into Wednesday. The
wind trajectories are not ideal for lake-effect in Vilas County,
as they become too northerly, so accumulations will be capped at
1 to 3 inches. Gale force gusts will be possible on Lake Michigan
later Tuesday night into Wednesday evening, and a Gale Watch has
been posted.

A deep upper level trough moves into the area Thursday night and
Friday and sets up camp over the western Great Lakes through the
weekend. Periods of light snow can be expected during this time
frame.

Temperatures will remain well above normal through Tuesday.
A decent surge of colder air and gusty north winds follows the
midweek clipper system, leading to colder temperatures from mid-
week through the weekend.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 600 PM CST Mon Jan 12 2026

VFR conditions across the area early this evening. Expect this to
change for mainly northern WI overnight as a clouds arrive from
the west and lower, with IFR cigs by sunrise Tuesday.
Additionally, mixed precip will develop, which will primarily
occur in northern WI (KRHI TAF site). Brief periods of mixed
precip (20-40% chance) are possible in central WI early this
morning, and in east-central WI mid-morning. The lower cigs arrive
in central WI Tuesday morning, and in east-central WI Tuesday
afternoon.

Light winds from the W/SW tonight, then increasing from the W on
Tuesday with gusts to around 25 kts. LLWS will also develop late
tonight and continue through the TAF period.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 2 AM to 9 AM CST Tuesday for WIZ005-
010>013-018-019-021-073.
&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......KLJ

NWS GRB Office Area Forecast Discussion