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Area forecast discussion
National Weather Service Green Bay WI
531 am CST Tue Nov 12 2019

Updated aviation portion for 12z taf issuance

Short term...today...tonight...and Wednesday
issued at 320 am CST Tue Nov 12 2019

Lake effect snow should end in Vilas County by noon as winds back
to the west and diminish. Additional snow amounts of an inch or
two are possible. Sunny and unseasonably cold weather will prevail
today, with highs twenty or more degrees below normal. A few record
low maximum temperatures are possible.

Skies should be clear this evening, and then clouds will increase
after midnight as an upper trough approaches from the plains states.
Low temperatures will be during the evening hours with steady or
slowly rising temperatures after the clouds arrive. Lows will be
well below normal.

A light to moderate snowfall is expected Wednesday as the combination
of upper jet dynamics and low level warm advection produce upward
motion and saturation of an initially dry atmosphere. The best
combination of the two forcing mechanisms is across the eastern
half of the forecast area where two to three inches should fall.
An inch or two is likely further west. Snow to water ratios will
be rather high for this early in the season, so it would not be
surprising for a few places near Lake Michigan to receive four
inches of snow. It is possible that a Winter Weather Advisory may
be issued later today for parts of eastern Wisconsin.

Long term...Wednesday night through Monday
issued at 320 am CST Tue Nov 12 2019

After the active weather system departs with the shortwave
Wednesday night, the long term forecast will be fairly quiet into
the weekend. Return flow will bring the next chance for active
weather over the weekend, as well as our first chance for above or
near normal temperatures in quite some time.

Wednesday night, light snowfall will continue as the upper level
trough exits the region overnight. Up to another inch of snow
could fall before midnight, mainly across east-central Wisconsin.
A dry upper ridge will build in behind the departing shortwave on
Thursday, which will bring a return to quiet conditions through
the end of the work week. The trade off however will be continued
access to the colder air from the north, which will keep our
temperatures below normal through the start of the weekend.

By Saturday, the upper level ridge will move off to our east as
the next shortwave approaches Saturday night. An extended period
of light precipitation is then expected, with warmer return flow
allowing for some light mixed precipitation or rain to fall Sunday
afternoon. That said, the access to southerly to southwesterly
flow near the surface will allow temperatures to rise towards the
upper 30s and possibly even lower 40s. How warm it gets by next
Monday will be largely dictated by the strength of the warm front
a week from now, but at least we'll be closer to normal
temperatures for mid November.
&&

Aviation...for 12z taf issuance
issued at 531 am CST Tue Nov 12 2019

Scattered lake effect snow showers and MVFR conditions
are possible north of egv and arv this morning. Clear skies are
expected otherwise today through this evening. Clouds will
increase tonight, though it will remain VFR.

Light snow and lower ceilings and visibilities will arrive from
the west Wednesday and continue Wednesday night.
&&

Grb watches/warnings/advisories...
Winter Storm Warning until 9 am CST this morning for wiz005.
&&

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