NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 140922
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
322 AM CST Wed Jan 14 2026

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Slippery roads, parking lots and sidewalks expected this
  morning as temperatures quickly fall well below freezing.

- Accumulating lake-effect snow and areas of blowing snow may
  cause localized travel concerns in north-central Wisconsin and
  northern Door County today.

- Widespread light snow late Thursday afternoon through Friday,
  with additional chances for light snow into the weekend.

- Much colder today. Temperatures moderate by Friday, before
  another reinforcing shot of cold air arrives this weekend.

&&

.DISCUSSION...
Issued at 321 AM CST Wed Jan 14 2026

Arctic cold front is dropping across the region early this
morning. Ahead of the front, temps were still in the mid 30s,
while falling into the 20s and teens just behind the front. Burst
of rain/snow has shifted to mainly snow as it drops across eastern
WI early today. Slippery conditions are expected on untreated
roads, parking lots and sidewalks with recent precipitation and as
temperatures continue to fall.

Lake effect snow showers flared up in wake of the front and as
sharp primary shortwave trough shifted through the area. Though
inversions are lower, lake EQL are around 5-6kft and given the
40kt in the cloud-bearing layer pushing the lake effect farther
inland than normal, along with favorable NW wind trajectories,
put quick Winter Weather Advisory up for Vilas early this morning.
Gusty northwest winds, over 30 mph at times, is also leading to
areas of blowing snow, reduced visibility. Lake effect will
gradually diminish after daybreak as inversions lower, but expect
locally hazardous travel to linger through the morning. May need
to extend the advisory, or at least issue follow-up SPS. Other
location that could see lake effect today will be northern Door.
Ice is thin on Bay of Green Bay, so there could be fluxes lead to
the lake effect with preconditioning plume off central Lake
Superior. Not expecting much snowfall (inch or two), but the snow,
along with gusty winds, blowing snow could lead to locally
hazardous travel. Prime time for the lake effect in Door would be
12z-18z based on forecast soundings. Though intensity of lake
effect fades later today and tonight, it will continue for both of
these areas. Elsewhere, went more bullish with clouds and
flurries as the wave drops through. Highs today will struggle to
reach the lower teens north, and should stay steady in the upper
teens, lower 20s elsewhere.

Next system will be dropping across the northern plains on
Thursday. Snow with this from warm air advection will arrive
over central and north-central WI by sunset, spreading over the
entire region on Thursday night. Additional rounds of mainly light
snow occur into Friday as the broad trough settles over the central
CONUS to the Great Lakes, with embedded shortwaves in the trough
focusing the times of more steadier snow. Overall, the setup still
favors widespread light snow of an inch or two from late Thursday
through Friday night, but there are signals that areas of a bit
more accumulation could occur. These details are hard to pin down
at this point. In general, NBM/LREF probabilities seem too low
compared a glance at deterministic models that are using 10:1
ratio for their snowfall projections. There will also be numerous
lake-effect snow showers over north-central at times.

Temperatures will be more down than up into next week. Readings
bottom out Today into Thursday, but then rebound on Friday with a
few spots around 32. Reinforcing shot of even colder air arrives
over the weekend and lasts into early next week. This will result
in sub-zero min temps and wind chills as cold as 10 below to 25
below zero during the late weekend and early part of the next work
week.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1048 PM CST Tue Jan 13 2026

The fast moving cold front is on its way into the region at the
beginning of the TAF period and will sweep across the region
through the early overnight hours. Accompanying the front will be
wind gusts up to 25 to 30 knots and brief snowfall that will lower
visibility across the region. Included a TEMPO group for the areas
most likely to be impacted for the brief period of sudden but
intense snowfall. Ahead of this front, winds have dropped off at
the surface, so made a mention of some LLWS again but would expect
this to be unnecessary once the front arrives and winds get
better mixing to the surface.

Ceilings during this period will start as a mix of MVFR in the
north and VFR still in portions of central and east-central
Wisconsin but should drop to MVFR as the front rolls through.
Finally, any wind gusts will likely linger on into Wednesday, with
periodic gusts up to 20 to 25 knots through Wednesday afternoon.

&&

.MARINE...
Issued at 321 AM CST Wed Jan 14 2026

Forecast soundings and ensemble winds/gusts still on track showing
solid 35-40 kt gale gusts through late this afternoon. Winds taper
to 30-35 kts this evening. Even with an offshore wind direction,
high waves and freezing spray will occur, especially toward open
waters of Lake Michigan.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM CST early this morning for
WIZ005.
&&

$$

DISCUSSION.....JLA
AVIATION.......Uhlmann
MARINE.........JLA