829
FXUS63 KGRB 191125
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
525 AM CST Sun Jan 19 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Wind chills of 20 to 40 degrees below zero are expected late
  tonight through Wednesday morning. The coldest wind chills will
  occur Monday night into Tuesday morning when wind chills as low
  as 40 below zero will be possible.

- A Cold Weather Advisory is in effect through 9 PM Monday. An
  Extreme Cold Warning will likely be issued for late Monday
  night into Tuesday morning.

- A warming trend will start on Wednesday which will continue into
  the weekend. High temperatures ranging from 10 to 20 degrees on
  Wednesday will warm into the mid 20s to low 30s by Saturday.

&&

.DISCUSSION...
Issued at 311 AM CST Sun Jan 19 2025

Short Term...Today...Tonight...and Monday

Arctic air will continue to move into Wisconsin for the next few
days. The air is very dry, so we expect mostly clear skies except
for northern Door county and Vilas county where lake effect clouds
and snow flurries are possible. MOS temperature guidance seems to
be a little too cold, especially for the Fox Valley and lakeshore
where there is no snow cover. Wind chills will be between 20 and
30 below zero much of the time through Monday, so will continue
the Cold Weather Advisory.

Long Term...Monday Night Through Saturday

As has been extensively messaged, focus for the extended remains
on cold weather impacts as the snow drought continues. Only hope
for snow in the foreseeable future comes late Wednesday into
Thursday as yet another clipper system in the wave train passes
to our north. This being said, snowfall amounts should be held
down to a couple tenths of an inch due to lack of moisture.

Temperatures/wind chills... Brunt of the cold air will settle in
late Monday night/early Tuesday morning as lows drop between 10
and 20 below zero for most. Combined with a marginal but
persistent northwest wind, it won`t take a lot to quickly tank
wind chills between 25 and 35 degrees below zero. Readings
approaching 40 below will be possible in usual cold spots. Suffice
to say, plan on a prolonged period of cold-related impacts
through at least Wednesday morning. WAA then takes over on
Wednesday as surface ride builds over the Great Lakes, moderating
temperatures back to near, though slightly below, average.

Headlines... Cold Weather Advisory remains in effect area-wide
through 9 PM Monday. Advisory will then more than likely be
replaced with an Extreme Cold Warning for the Monday night/Tuesday
morning time frame as guidance holds. We then drop back down to
Advisory criteria by Tuesday night/Wednesday morning, although
there are still some questions as to end time given a tighter
wind chill margin.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 524 AM CST Sun Jan 19 2025

Scattered lake effect clouds are possible north of a RHI to IMT
line, and north of 3D2 over the northern part of the Door Peninsula.
Otherwise, mostly clear skies and excellent visibility is expected
across the region through at least Monday.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory until 9 PM CST Monday for WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&

$$

DISCUSSION.....RDM/Goodin
AVIATION.......RDM