NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 170519
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1119 PM CST Fri Jan 16 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Light snow to continue over most of the area through Saturday
  morning. Light to moderate lake effect snow will result in
  greater snowfall amounts in Vilas County (4 to 6"), where a
  Winter Weather Advisory is in effect until noon on Saturday.

- Bitter cold arrives this weekend into early next week, with a
  broad 60-100% chance of wind chills colder than -20F both
  Monday and Tuesday mornings.

- Active pattern remains in place through next week, with several
  clipper systems bringing additional opportunities for
  accumulating snow.

&&

.DISCUSSION...
Issued at 109 PM CST Fri Jan 16 2026

Snow chances... Radar shows that the initial round of snow has
exited the area, with subsidence behind the line resulting in a
lull in snow activity for some. However, comma head returns have
begun to fill back in this afternoon as additional shortwave
energy pivots through the western Great Lakes. CAMs start to show
the snow squall parameter flagging within these returns due to
marginal lift and decent saturation, though remain pessimistic on
this front given a lack of better instability, a strong arctic
front, or focused mid-level FGEN. Could certainly see some
convective snow showers, though likely not any organized squalls.
Regardless, biggest change to this forecast package revolves
around lake effect potential in the typical snowbelts across far
north-central Wisconsin as winds already begin to take on a more
northwesterly component along the back edge of the departing
surface low. Seeing several ingredients coming together for at
least a low-end lake effect event, namely as DGZ heights increase
to around 6 to 7k ft and delta Ts hit the sweet spot between 13
and 15C. As such, have opted to increase both PoPs and QPF in the
northwest snow belts, resulting in a solid 3 to 5 inches of total
snow across Vilas due to effective dendrite production. Some CAMs
go so far as to hint at the possibility of a mesoscale banding
feature developing, which would significantly boost snowfall
amounts were it to materialize. For the time being, have gone with
a Winter Weather Advisory for Vilas through 18Z Saturday, though
this will continue to be monitored.

Active pattern refuses to let up through the end of next week as
the 500 mb wave train proceeds at full steam ahead. We will be
afforded a brief break in precip late Saturday into early Sunday
before our next clipper system makes an appearance later Sunday
morning. Widespread light snow will once again be possible, though
far north-central Wisconsin will once again receive the brunt of
the snow. Yet another clipper system then arrives this week, with
the current trajectory looking to bring more impactful snowfall to
the rest of the forecast area.

Temperatures... Forecast concerns for the extended shift to the
arrival of arctic air this weekend into early next week as an
anomalously cold 850 mb airmass (nearing absolute min relative to
climo) settles over the Great Lakes. With high temperatures
failing to meet zero degrees at many locations and a
strong/consistent signal for at least 40 knot winds at 850 mb,
wind chills are progged to plummet to between 15 and 25 degrees
below zero at most locations, colder further west. The LREF grand
ensemble currently shows a broad 60 to 100% probability of lower
than -25F wind chills early Monday and Tuesday mornings, which is
heavily influenced by the high- performing ECMWF. As such, it
currently looks pretty slam dunk for cold weather headlines early
next week, especially as long-range guidance continues to trend
colder. Temperatures then moderate slightly mid- week as another
clipper system steers the core of the colder air off to the east.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1118 PM CST Fri Jan 16 2026

Cyclonic flow will bring continued light to moderate snow showers
at times through Saturday morning. Conditions will range from
VFR/MVFR to MVFR/IFR with the snow showers. Further north, light
to moderate lake effect snow will continue in/near KRHI through
Saturday morning. Winds will be predominantly out of the
northwest, with surface gusts between 15 and 20 knots, especially
during the daytime.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST Saturday for WIZ005.
&&

$$

DISCUSSION.....Goodin
AVIATION.......Kurimski