Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 212037

Area Forecast Discussion
National Weather Service Green Bay WI
237 PM CST Tue Nov 21 2017

Forecast discussion for routine afternoon forecast issuance

.SHORT TERM...Tonight and Wednesday
Issued at 235 PM CST Tue Nov 21 2017

Lake effect snow showers in northern Wisconsin should dissipate
by late evening as low level winds diminish and become westerly.
Skies should clear over most of the area overnight as a surface
high moves across Wisconsin. Skies should begin as sunny
Wednesday, but high clouds will arrive in the afternoon ahead of a
weakening clipper system. Lows tonight and highs Wednesday will
be 5 to 10 degrees below normal.

.LONG TERM...Wednesday Night Through Tuesday
Issued at 235 PM CST Tue Nov 21 2017

Various systems passing by in the northwest flow aloft will
provide a few chances of precipitation and fluctuating
temperatures for much of the period. Cold air on northwest winds
at times will produce periods of lake effect snows far north.

A quick moving clipper system with frontal system will be passing
over the region Wednesday night. System will be moisture starved
but a few snow showers or flurries will be possible along or near
the fropa. At this time a dusting of snow cover is possible late
Wednesday night. If accumulation trends increase, then a mention
in the HWO will be needed.  High pressure to quickly slide over
Thursday with return flow already developing toward Thursday night
and continuing into Friday morning.

Next more robust clipper or shortwave trough to drop over the
area later Friday into Saturday morning. Air mass will be warm
enough at the start for mainly rain but colder air advecting into
the region behind the system will turn the pcpn type to a mix
and to mainly snow north. System precipitation departs rather
quickly before colder air arrives, so snow amounts appear limited.
Winds will be rather strong with this system.

Rest of the weekend will be breezy and cold before another warming
trend for the start of the new work week ahead of another system.

.AVIATION...for 18Z TAF Issuance
Issued at 1157 AM CST Tue Nov 21 2017

VFR ceilings between 3500 and 4500 feet should continue
in most areas through early evening before clearing. The exception
is north of Rhinelander where lake effect snow showers and MVFR
ceilings will continue into the evening hours. Brief IFR possible.

Clear skies should prevail late tonight through midday tomorrow,
then middle and high clouds will arrive ahead of a weak clipper
system. It may produce a few hours of light snow or flurries
tomorrow night. Accumulations of a dusting to an inch are



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