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Area forecast discussion 
National Weather Service Green Bay WI
312 am CST Tuesday Jan 27 2015

Forecast discussion for routine morning forecast issuance

Short term...today...tonight...and Wednesday
issued at 311 am CST Tuesday Jan 27 2015

At 3 am...area radars show a diminishing region of light snow
over eastern Wisconsin. Light snow will wind down quickly this
morning over most locations as a weakening short wave trough
quickly shifts southeast and phases with the large East Coast
storm. A surface trough will also drop southward as well this
morning while a ridge of high pressure builds into the region from
the north. A subtle surface boundary or convergent area extended
from Vilas County to central WI to southeast WI but radar shows
little or no return in this region. With an east or northeast
surface to 850 wind lingering to around noon today...its possible
light lake effect snow showers may linger. Will monitor for any
subtle bands of snow from Lake Michigan as the system snow ends.

Otherwise cloud trends will become the primary forecast issue
today into Wednesday. Light winds followed with return flow warm
air advection later today through Wednesday will tend to keep
clouds around. Sat imagery shows widespread MVFR/IFR clouds
upstream to the northwest half of Minnesota and in the surface
high pressure system. But can expect some breaks over eastern
Wisconsin today as the surface high pressure ridge slides
southward and a period of subsidence in the of the short wave
trough. Imagery already showing decreasing clouds over Northern
Lake Michigan early this morning.

Currently have a dry forecast for Wednesday as a short wave and
surface trough approaches the state. Considered light freezing
drizzle for Wednesday...but forecasts indicate middle levels are moist
but lower levels start out on the dry side. Some forecast
soundings suggest a possible light mix of light ice pellets/S over northern
Wisconsin in the afternoon...but consensus of the model runs is
to remain dry at this time.

Long term...Wednesday night through Monday
issued at 311 am CST Tuesday Jan 27 2015

Upper level troughs moving into the region from the west will
bring chances for precipitation to the forecast area Wednesday
night through Thursday morning. BUFKIT time sections from the 00z
NAM indicated potential for sleet and/or freezing rain Wednesday
night but quantitative precipitation forecast totals were rather light. Totals were a little
higher from the 00z GFS but leaned more toward snow...especially
across northern Wisconsin. Opted to mention some sleet/freezing
rain in parts of central and east central Wisconsin on Wednesday
night...with just snow farther to the north. Expect mainly snow on
Thursday morning...but cannot rule out freezing drizzle as the
snow winds down. Cold air on the back side of the departing system
will bring chances for snow in the Lake Superior snowbelt and
temperatures should be colder into the weekend. There are some
differences among the models regarding snow associated with an
Arctic cold front over the weekend...so have mainly slight chances
probability of precipitation going for now.
&&

Aviation...for 06z taf issuance
issued at 1019 PM CST Monday Jan 26 2015

The system producing the snow will continue to slowly shift off to
the southeast tonight...but MVFR/IFR ceilings will linger in the moist cyclonic
flow remaining behind the departing system. Ceilings in central WI may
even drop into the LIFR category for a while overnight.
&&

Grb watches/warnings/advisories...
none.
&&

$$

Short term.....Tdh
long term......mg
aviation.......skowronski

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