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Area forecast discussion 
National Weather Service Green Bay WI
504 am CST Thursday Nov 26 2015

Updated aviation portion for 12z taf issuance

Short and tonight
issued at 402 am CST Thursday Nov 26 2015

Plenty of forecast challenges today into tonight due to precipitation type
and changeover trends for the Thanksgiving travel.

For the start this morning...area radars show expanding rain from
the south. Will have a ramp up pop this morning before rain
becomes widespread late morning into the afternoon. The surface
cold front at 08z extended from around Vilas County meanwhile the
leading edge of the cold front extended from Vilas County to near
La Crosse. Colder is lagging behind the front so anticipate the
precipitation type at the onset will be rain. As the colder air seeps in
from the north...precipitation type will also turn from rain to mix and
eventually all snow later today into tonight.

Baroclinc is prognosticated to bisect the area from around auw to imt
toward 00z as the rrq region of the upper jet. Anticipate a quick
turn to all snow as this large scale region slides over. However
bet quantitative precipitation forecast is also sliding to the will likely have a period
of moderate snow with sleet on the edge of this higher quantitative precipitation forecast region
starting late this afternoon over north central Wisconsin before
spreading southward into central and northeast Wisconsin. Issued a
winter advisory for a mix of snow accumulation and sleet...however
the primary issue is wet roads freezing as temperatures fall below
freezing this evening. Its possible southern areas of Oconto and
Marinette counties may need to be added to the advisory...but the
colder air is slower to reach eastern Wisconsin this evening.
Forecast soundings suggest the snow growth region is delayed.
For areas south for the advisory..will issue a Special Weather Statement due to a
changeover much later tonight...or after midnight.

Long term...Friday through Wednesday
issued at 402 am CST Thursday Nov 26 2015

The system will continue to move away from the area on Friday.
Will continue a small chance of light snow early in the day...
otherwise clouds will be on the decrease during the day.
Gusty northerly winds will also diminish as the day progresses.
For Friday night...clear skies and light winds...along with a
fresh snow pack across the north will allow temperatures to
plumet...especially in our typical colder locations. Our
typical cold spots could be down to near zero.

High pressure will dominate the weather pattern for the weekend
into Monday. The next weather maker will affect the area late
Monday into Tuesday night as closed upper low at 500mb moves
across the central United States. This system has the potential
for an accumulating snowfall...however the European model (ecmwf) is more
aggressive with wrapping warm air into the western Great Lakes
for more rain than snow at the onset of the system. The GFS was
somewhat colder and would have more snow than rain at the onset
except for maybe across northeast Wisconsin where low level winds
would come off the warmer waters of Lake Michigan. The system
should exit the region Tuesday night...bringing an end to the

Beyond Saturday and Sunday morning...temperatures will be at or
above normal next week.

Aviation...for 12z taf issuance
issued at 503 am CST Thursday Nov 26 2015

Ceilings and visibilities will deteriorate into IFR/LIFR
conditions today as rain becomes widespread. The rain will mix
with sleet or snow then change to all snow from north to south
later today into this evening over north central...central
Wisconsin and late evening and then later tonight over northeast


Grb watches/warnings/advisories...
Winter Weather Advisory from 4 PM this afternoon to 2 am CST
Friday for wiz013-020-021-031-035>037.

Winter Weather Advisory from 1 PM this afternoon to 2 am CST
Friday for wiz010>012-018-019-030.


Short term.....Tdh
long term......eckberg

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