Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 130913

Area Forecast Discussion
National Weather Service Green Bay WI
313 AM CST Sat Jan 13 2018

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Sunday
Issued at 313 AM CST Sat Jan 13 2018

Aside from scattered lake-effect clouds and flurries over northern
Vilas county this morning, clear skies are anticipated today. Wind
chills of 20 to 30 below zero will continue over north central
and central WI through mid to late morning, so will let the
current headline run its course. High temperatures will only be in
the single digits and lower teens.

The surface ridge axis will move across the forecast tonight,
resulting in decreasing winds, clear skies and very cold
temperatures. Lows will be in the single digits below zero in the
Fox Valley and lakeshore areas, with teens and lower 20s below
zero farther northwest. Wind speeds will drop below 5 mph at most
locations overnight, so it is questionable whether or not another
wind chill advisory will be issued for tonight into Sunday
morning. Regardless, it will still be dangerously cold, and the
threat will be detailed in the Hazardous Weather Outlook.

After a dry morning with increasing high and mid level clouds,
light snow is expected to move into the forecast area Sunday
afternoon. Models disagree on the timing, but it appears most
likely to overspread north central and central WI during the
late afternoon. The snow will develop as a result of increasing
WAA ahead of a cold front. Highs will remain cold, ranging from
the upper single digits to the teens.

.LONG TERM...Sunday Night Through Friday
Issued at 313 AM CST Sat Jan 13 2018

The main story will be the prolong period of snow from Sunday
night into Monday night. A widespread snowfall of 3 to 6 inches
are expected across the region. The lowest totals are anticipated
to be across central Wisconsin northeast towards Florence.
Snowfall totals across far north-central Wisconsin will be
locally higher, especially across northwest Vilas county where
lake effect snow showers will enhance the totals. Things get very
interesting from the eastern Fox Valley east to the lake. Models
tonight are indicating the low level wind field should turn to the
east off the lake Monday afternoon into Monday evening, then turn
northeast later Monday evening before backing to the north after
midnight. 850mb temperature forecast was around -13 C, creating
lake to 850mb temperatures differences around 16 C. Bufkit
soundings also impressive with capes of 500 to 700 J/KG and
EQL levels around ten thousand feet. Although the easterly flow
will be light, enough period of time for snowfall totals to be
enhanced due to the lake contribution across the lakeshore
counties. Would not be surprised if the snow would become
locally heavy at times Monday afternoon/evening. Based on wind
trajectories, the highest totals are anticipated to be across Door
county where there will be a longer period of a favorable wind
direction off the lake compared to locations just to the south
where winds will be backing through the night. However, all it
will take is for an organized lake band to move onshore to mess
up snow totals. For now, will have 6 to 8 inches across the
lakeshore counties with locally higher amounts possible,
especially across Door County.

Cold northerly flow and upper trough exiting the region will allow
for some lingering light snow shower or flurry activity Tuesday
morning. Lake effect snow showers will continue at times into
Tuesday evening across the far north. Tuesday night will be colder
than Monday night due to less cloud cover and light winds.
Wednesday will continue to be cold with highs mainly in the teens.
Milder air returns to the region on Thursday with highs in the
20s and even warmer on Friday with highs in the 30s. Mild Pacific
air is expected for the first half of next weekend.

.AVIATION...for 06Z TAF Issuance
Issued at 826 PM CST Fri Jan 12 2018

Primarily VFR conditions are expected for the next 24 hours,
though lake-effect clouds will affect north-central Wisconsin at
times. The clouds are expected to remain primarily north of the
TAF sites.

Wind Chill Advisory until 9 AM CST this morning for WIZ005-


SHORT TERM.....Kieckbusch
LONG TERM......Eckberg
AVIATION.......Skowronski is the U.S. government's official web portal to all federal, state and local government web resources and services.