Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 150414

Area Forecast Discussion
National Weather Service Green Bay WI
1014 PM CST Sat Dec 14 2019

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Sunday
Issued at 204 PM CST Sat Dec 14 2019

Main concern in the short-term portion of the forecast will be the
potential for light snow/flurries through this evening and light
lake effect snow across the north-central.

A shortwave passing through the area early this evening, will allow
for a few light snow showers or flurries to continue across most
locations. Otherwise, as a surface low pressure system slide off to
the east of the area, cyclonic northwesterly flow will increase
across north-central Wisconsin. This, along with 850 mb temperatures
dropping into the -16C to -18C, will create favorable wind
trajectories and delta-T values to produce lake effect snow across
north-central Wisconsin. Specifically, northern Vilas County would
have the best chance of seeing light snow accumulations. This will
quickly diminish by Sunday morning as winds shift to the west ahead
of a surface ridge building across the Upper Mississippi Valley.
Drier air associated with the high, will allow much of the area to
become mostly clear for much of the day Sunday. High temperatures
are expected to be in the teens to around 20, warmest near the Lake
Michigan shoreline. Overnight lows are expected to be in the single
digits below zero central/north-central to the single digit to low
teens above zero east-central and far northeast.

.LONG TERM...Sunday Night Through Saturday
Issued at 204 PM CST Sat Dec 14 2019

Surface-based low pressure will develop over the Plains States
starting Sunday night and expand east during the first half of
the work week. Although energy and moisture associated with this
system will spread northeast as it moves east, precipitation is
expected to stay south and east of our area. Temperatures will
drop as the system integrates with broader low pressure in
Canada and pulls arctic air south into our region for a couple of
days. Then on Thursday, another low will strengthen over the
southern Rockies and move out over the High Plains on Friday.
Temperatures will moderate at that time as the low draws warmer
air into the northern Midwest.

.AVIATION...for 06Z TAF Issuance
Issued at 1014 PM CST Sat Dec 14 2019

Skies should clear overnight, with the exception of some bands of
lake effect clouds north of a Merrill to Iron Mountain line. There
may also be some clouds over Door County from cold air moving over
the bay. Snow showers with brief MVFR conditions are possible at
times at D25/LNL/EGV/RHI overnight.

After any lake effect clouds dissipate, Sunday should feature
good flying weather that will continue Sunday night.



SHORT TERM.....Cooley
AVIATION.......RDM is the U.S. government's official web portal to all federal, state and local government web resources and services.