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Area forecast discussion
National Weather Service Green Bay WI
541 am CST Fri Nov 15 2019

Updated aviation portion for 12z taf issuance

Short Saturday
issued at 416 am CST Fri Nov 15 2019

High pressure will move from Lake Winnipeg towards
the eastern Great Lakes by tomorrow night. It will provide drier
air and weak cold advection today which should result in a sunny
day with high temperatures about ten degrees below normal.

As the surface high moves east of the region tonight, low level
winds will become northeast and later east. Low level temperatures
are still cold enough to produce some lake effect clouds across
eastern Wisconsin and perhaps snow flurries near the Lakeshore.
Warm advection and a steady breeze will keep temperatures from
falling much tonight.

Clouds will increase further on Saturday as a low pressure system
approaches from the northwest. Highs should reach freezing or even
a few degrees higher in the afternoon despite the cloud cover.

Long term...Saturday night through Thursday
issued at 416 am CST Fri Nov 15 2019

Several periods of active weather are expected for the long term
forecast. Snow and mixed precipitation will move through both
Saturday night into Sunday, Monday night into Tuesday, and
Thursday. Temperatures will moderate through the extended, coming
to close to normal by the middle of next week.

Saturday night into Sunday, an upper level trough will bring
active weather to the region. Precipitation should start as all
snow for the region as it overspreads in to the afternoon. As warm air advection
continues, some rain will likely mix into the snow, especially
along the Fox Valley and areas near Lake Michigan. In central
Wisconsin, temperatures will hover near freezing, which will make
for a fairly blurry line between rain and snow through the day.
This will likely impact snow totals if the warm air intrudes
further north across central to north-central Wisconsin. As the
trough moves through Sunday evening, dry air will intrude at the
middle to upper levels, which will cut off the source of ice
crystals for the region and create a chance to see some mixed
precipitation and freezing drizzle. Travel will likely be impacted,
but impacts may be reduced if the drizzle falls on the fresh snow
instead of freezing on paved surfaces.

Monday will be quiet for most of the day, but a weak shortwave
will bring a quick round of precipitation into the region
overnight into Tuesday, primarily for northern Wisconsin. Much
like the system the previous day, a mix of precipitation types
will be likely for the area.

Weak ridging then moves into place Tuesday night and will keep
quiet conditions in place through Wednesday. Weak southerly flow
will even push our high temperatures into the middle to upper
30s, within a few degrees of normal.

Another system is then in the works for Thursday with another
upper level trough, but the details on this are yet unclear.

Aviation...for 12z taf issuance
issued at 541 am CST Fri Nov 15 2019

Clearing skies are expected today with good visibility and light
surface winds. Lake effect clouds with MVFR ceilings are possible
this evening near the lake and Bay, and across the rest of the
area late tonight. Ceilings will probably rise to VFR by midday

VFR ceilings are expected Saturday afternoon and evening. MVFR/IFR
conditions are likely late Saturday night and Sunday as light
snow arrives ahead of a low pressure system.

Grb watches/warnings/advisories...

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