363
FXUS63 KGRB 220936
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
336 AM CST Wed Jan 22 2025

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Light snow is expected across the region today into this
  evening, with lake effect snow continuing across north-central
  Wisconsin late tonight into Thursday. Snowfall amounts will
  generally be less than an inch; however, 1-2 inches of snow is
  possible across northern Vilas County through Thursday.

- One last colder night is in the forecast for Thursday night
  before a warming trend arrives for the end of the work week and
  the weekend.

&&

.DISCUSSION...
Issued at 335 AM CST Wed Jan 22 2025

Short Term...Today...Tonight...and Thursday

Light snow and flurries are expected today as a clipper system
tracks through the western Great Lakes region. Despite a warm
front across Minnesota, the system is expected to occlude with
northeast Wisconsin missing the warm sector and mainly seeing the
occluded front late this afternoon into this evening. Although the
region will miss out on the warm sector, temperatures today will
still warm into the middle teens across the north, with
temperatures around 20 across central and east-central Wisconsin.
Snowfall amounts today will generally be light, with a dusting or
a few tenths of an inch possible.

Much of the snow will end this evening as the occluded front and
clipper system head off to the east. The main exception will be
across far north-central Wisconsin as low level winds turn north-
northwest with lake effect snow or flurries continuing across the
north late tonight into Thursday with delta T values in the mid
20s and a convective cloud depth around 5k ft. The lake effect
will continue until Thursday afternoon when winds back westerly as
high pressure builds in across the upper Mississippi Valley. The
lake effect snow across the north should generally be light, with
a dusting or a few tenths of an inch possible; however, around an
inch or so will be possible across far northwest Vilas County in
the Lake Superior snowbelt region. Lows tonight are expected to
range from around zero across western portions of central and
north-central Wisconsin to around 10 along the Lake Michigan
shoreline. Highs on Thursday are expected to range from around 10
across north-central Wisconsin to the upper teens across east-
central Wisconsin and the lakeshore.

Long Term...Thursday Night Through Tuesday

The extended will feature a warmup from the bitter cold
temperatures from early this week, but not before one more
relatively colder night Thursday night. The extended will
mainly be dry, but will keep an eye on the chance for some
flurries on Saturday.

Temperatures...
One last cold night is in the forecast for Thursday night as
skies clear and winds drop off. Air temperatures by Friday morning
are expected to range from ten below in the coldest spots of
north- central Wisconsin to right around zero near the Fox Valley.
This brings wind chills to around twenty to ten below zero
respectively. Probabilistic guidance still keeps the chance of
approaching Cold Weather Advisory low, so no headlines are
anticipated at this time, but this will still prove to be a fairly
cold overnight period.

Behind the cold, a quick warmup is expected the following days
with highs getting back towards the 20s and 30s for Saturday. A
fast moving cold front will bring temps back towards the teens for
Sunday before we again warm towards the upper 20s and lower 30s
next week.

Precipitation...
The fast moving cold front Saturday afternoon and evening will be
the only feature of note capable of producing precipitation in the
extended. The forecast remains dry for now as this is still a very
dry airmass, but a few of the latest ensemble members do produce a
few flurries. If this signal persists, may see flurries or a few
light snow showers added to the forecast, but would expect minimal
impacts and accumulations given the lack of moisture and forcing
with this feature.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1047 PM CST Tue Jan 21 2025

VFR conditions will continue late this evening as mid-level
clouds thicken/lower across the region. A mix of MVFR/VFR
conditions are expected on Wednesday, as a clipper system drops
across the Great Lakes. Look for some flurries and snow showers to
accompany this system, but amounts will be on the light side,
mainly under an inch. Some brief reduction in visibilities are
expected, mainly across northern WI. Have kept TEMPO/PROB30 groups
across central and east central WI where the snow will be less
widespread due to weaker forcing and dry air, but will have
prevailing snow at RHI where the most widespread snow activity is
expected.

Southwest/south winds are expected overnight into Wednesday
morning. Some gusts to ~20 kts are expected, but gusts at the
surface will be somewhat limited tonight due to the stabilizing
effects of warm air aloft along with the reduced mixing at night.
But as the pressure gradient tightens early Wednesday, more gusts
are expected at the surface. Winds will shift to the west/northwest
Wednesday evening. LLWS is expected late this evening into
Wednesday morning as winds at 2000-3000 ft increase to 40-45 kts.

&&

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

&&

$$

DISCUSSION.....Kurimski/Uhlmann
AVIATION.......Bersch

NWS GRB Office Area Forecast Discussion