Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 272348

Area Forecast Discussion
National Weather Service Green Bay WI
648 PM CDT Thu Apr 27 2017

Updated aviation portion for 00Z TAF issuance

Issued at 359 PM CDT Thu Apr 27 2017

Snow continues to taper off over the Northwoods, so will let the
advisory expire at 4 pm.

.SHORT TERM...Tonight and Friday
Issued at 248 PM CDT Thu Apr 27 2017

Colder air wrapping into the departing system continues to turn the
mix to mainly snow with the exception of eastern Wisconsin. Web
cams showing some locations with several inches of snow. System is
winding down fairly quick from southwest to northeast but may
need to extend the advisory for another hour across the north due
to reports of moderate snow yet.

Next forecast issue is the rate of clouds departing overnight.
Satellite imagery shows plenty of clouds across the region, so
will extend the period of clouds overnight longer. With the
extensive clouds and mixing from winds, most areas should not
expect temperatures to plummet, even with the fresh snow cover.

For Friday, progs continue to lift the next system into southern
Wisconsin in the afternoon. While precipitation will overall stay
south, what clearing that does occur with the departing system
late tonight into Friday morning is trending to be shorter lived
due to the next system.

.LONG TERM...Friday Night Through Thursday
Issued at 248 PM CDT Thu Apr 27 2017

500mb trough across the western United States is expected to
deepen over the first half of the weekend, then slowly eject
northeast out of the four corners region Sunday into Monday.
The upper low is forecast to be across the western Great
Lakes region Monday afternoon into Monday night, then fill
as it heads northeast into Canada Tuesday. This system
will bring another potentially locally heavy rain event
to some areas of the Upper Midwest. By the end of the week,
500mb ridge is expected to build into the central United
States as another 500mb low deepens across the eastern
Great Lakes.

For Friday night, models continue to show system passing
to the south of the area. East-central Wisconsin will
be on the northern fringe of this system, thus continue
to have chances of rain mainly south of Green Bay.
Any chances of rain should end around midnight along
the lakeshore as the system moves east of the area.

Next system will begin to move towards the area Saturday
afternoon. With system well to the south of the area and
a 1035mb high across eastern Canada, concerned that models
are too quick in bringing rain back into our far southern
counties late Saturday afternoon. Was thinking rain will
move back into our southern counties during the mid to late
evening on Saturday. Even later Saturday night, there is concern
if precipitation would make it into far northern Wisconsin with
easterly flow. Precipitation should arrive across northern
Wisconsin by mid to late morning, thus the chances of snow
are diminished. Rain will continue at times through Monday
night. It may be mixed with snow at times late Sunday night/Monday
morning and Monday night into Tuesday morning.

High pressure builds into the region Wednesday and Thursday,
bringing dry conditions and temperatures closer to normal.

.AVIATION...for 00Z TAF Issuance
Issued at 641 PM CDT Thu Apr 27 2017

Isolated rain/snow showers should end early this evening, but
MVFR ceilings are expected to prevail well into the night. There
is some question about the timing of clearing across the southern
part of the forecast area, and whether or not it will clear at
all over the north. Will mention partial clearing late tonight,
except at the RHI TAF site, but this may need to be adjusted.
Regardless, expect conditions to improve to VFR as ceilings rise
Friday morning.




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