521
FXUS63 KGRB 190921
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
321 AM CST Mon Jan 19 2026

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Areas of blowing and drifting snow with sharply reduced
  visibilities this morning as northwest winds gust over 30 mph
  with arrival of arctic air. Worst conditions through mid
  morning. Winter Weather Advisory expanded over eastern WI,
  including the Fox Valley and lakeshore.

- Bitter cold wind chills as low as 20 to 30 below this morning.
  After a brief reprieve this afternoon, the low wind chills
  return to all areas tonight into Tuesday morning. Cold Weather
  Advisories extended until 10 am on Tuesday.

- Snow chances trending higher Tuesday night south of Highway 29
  (chances 50-70 percent).

- Another wave of bitter cold Friday into next weekend. This bout
  of cold will be more extreme that is occurring early this week,
  with chances of seeing wind chills down to 40 below zero 70 to
  80 percent over central WI. Chances for daytime highs staying
  below zero all areas up to 60-90%.

&&

.DISCUSSION...
Issued at 320 AM CST Mon Jan 19 2026

Arctic air arriving this morning with gusty winds. Areas of blowing
and drifting snow expected this morning. Bitter cold early this
week, relaxes some mid week, but then resurges late this week into
next weekend.

Snow and Blowing/Drifting Snow Today...
Lighter lake effect, with lower SLRs, persists over Vilas County
early this morning. Still a few hours of light to at times
moderate snow, so no change to the going Advisory there.
Otherwise, upper level trough with 850mb temps down to -25c digs
across and pressure gradient is tightening behind arctic front.
Wind gusts thus far have been 25-30 kts over central WI with vsby
reductions noted, but nothing too widespread. Despite traffic
webcams not showing anything too low in terms of vsby, call to
Marathon County did turn up lower vsby in more open western
Marathon County. Winds in the 1000-925mb layer do increase farther
east, with 40kts at top of mixed layer over eastern WI 9z-15z
teamed with cold air advection in that layer. Wind gusts of 30-40
mph in those areas will cause areas of blowing and drifting. Worst
conditions will be across Door County with stronger winds
forecast to mix off the bay and also as area of snow drops across
this morning. Have extended the Winter Weather Advisory from
Waushara northeast to southern Oconto and filled it in all the way
to the lakeshore. Strongest winds and most of the BLSN/DRSN will
be 4a to 9a, right in line for the morning commute. Main impacts
will be low vsby down to less than 1 mile at times and drifting
snow leading to snow covered and slippery roads. Will cover areas
not in any type of winter advisory in an SPS for the lower vsby.
Expect winds and BLSN/DRSN to back off this afternoon. Any
lingering light snow or flurries should shift to only Door County
by that time.

Bitter Cold into Tuesday...
Wind chills are dropping toward -25 over central WI early this
morning and readings 20-25 below will shift over the rest of the
area through late morning. Modest modification this afternoon even
as air temperatures stay below zero central to north-central and
stay in the lower single digits, but the colder wind chills return
tonight to all areas, including Door County, and last into Tuesday
morning. Have issued a Cold Weather Advisory for Door, and extended
the remaining advisories until 10 am Tuesday. High temperatures on
Tuesday afternoon will barely break zero central to north-central,
and will reach near 10 above elsewhere.

Clipper Snow Tuesday Night into Wednesday...
Shortwave in base of broad upper trough crosses the region Tuesday
night into Wednesday. Based on forecast soundings showing saturation
in the cold airmass, see no reason most of the area will not see snow.
See the last few days for a reference. Snow amounts at this point look
minor with chances for 0.1" up to 60% south of highway 29, while
the chances for 1" are 20-50% only over the southern portion of the
area (south of highway 10). Trends are up, and some models are liking
the higher end of ensembles (2-3" toward Oshkosh and Manitowoc).
Will be worth watching as the morning commute on Wednesday would
be impacted. Wouldn`t be surprised if light snow/flurries linger beyond
this system into Thursday.

Extreme Cold Friday into the Weekend...
Arctic high pressure of 1050mb over the plains arrives later
Friday into the weekend. As mentioned yesterday, sharp trough with
very cold air is nearby, and now today is shown to drop over the
western Great Lakes region. 850mb temps -30c before slightly
moderating into Saturday. Result is better agreement that Friday
is very cold with chances of seeing subzero highs areawide 60 to
90%, and chances for seeing wind chills less than 30 below 50-95%.
If these colder trends hold up, we will need Extreme Cold
Warnings for all areas Thursday night right through Saturday. Wind
chills drop to -10 late Thursday and don`t return to readings
warmer than that until Sunday afternoon. We`re starting to message
this next bitter cold snap.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1052 PM CST Sun Jan 18 2026

A mix of VFR and MVFR CIGs prevailed across the region late this
evening with a combination of light snow, flurries, and blowing
snow. The light snow will come to an end around TAF issuance, with
strong northwest winds developing across the region, with gusts as
high as 30-35 knots. These winds will generate blowing and
drifting snow with vsbys potentially dropping to IFR. The blowing
and drifting snow impacts will likely continue through Monday
morning mainly for the east-central Wisconsin TAF sites as winds
remain higher there the longest. Winds to gradually subside during
Monday afternoon and evening with the potential for some clearing
on Monday. Further north, lake-effect snow showers will persist
in north- central Wisconsin through midday Monday, which will keep
MVFR cigs at the KRHI TAF site. Winds will gradually subside
during Monday afternoon and evening with the potential for some
clearing on Monday.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 AM CST this morning for WIZ005.

Cold Weather Advisory until 10 AM CST Tuesday for WIZ005-010>013-
018>021-030-031-035>040-045-048>050-073-074.

Winter Weather Advisory until noon CST today for WIZ022-031-
037>040-045-048>050-074.

Cold Weather Advisory from 6 PM this evening to 10 AM CST
Tuesday for WIZ022.
&&

$$

DISCUSSION.....JLA
AVIATION.......Kurimski

NWS GRB Office Area Forecast Discussion