Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 271730

Area Forecast Discussion
National Weather Service Green Bay WI
1130 AM CST Mon Feb 27 2017

Updated aviation portion for 18Z TAF issuance

.SHORT TERM...Today...Tonight...and Tuesday
Issued at 338 AM CST Mon Feb 27 2017

Precipitation chances and types the forecast issue through

A surface boundary which stalled over central sections of
wisconsin last Sunday evening is lifting back north as a warm
front early this morning. Clouds and isolated bands of snow
showers or flurries were noted over northwest Wisconsin just
north of Eau Claire and drifting east to northeast. Will include
a period of flurries early this morning over north central
Wisconsin as the front lifts north over the area. Quite a range
in temps early this morning ranging from 6 below over the far
north with clear skies and north of the front to the mid 20s over
east central Wisconsin. Clouds spreading north should put a halt
across the north in the next few hours.

South winds and mostly sunny skies will provide above normal
temperatures today for most locations. Clouds will depart a little
later this morning over the north.

Attention then turns to an approaching Central Plains frontal
system late tonight into Tuesday. While the phasing of the surface
systems eventually occur Tuesday, will focus on the developing
850 mb trough and track tonight into Tuesday for precipitation
trends. Height 850 warm air advection occurs tonight into Tuesday
morning with precipitation spreading northeastward late tonight.
Forecast soundings and surface temperatures suggest a mix over
north central Wisconsin late tonight into Tuesday morning, then
all liquid for the rest of the day. Height 850 mb cold front sags
into northwest wisconsin including parts of north central areas
late Tuesday afternoon. Still anticipate mainly rain but pcpn type
may start to mix over late afternoon for areas north of

.LONG TERM...Tuesday Night Through Sunday
Issued at 338 AM CST Mon Feb 27 2017

Precipitation type is the main concern during the early part of
the long term forecast. Rain is the most likely type across the
forecast area at 00Z Wednesday, before cold advection behind a
departing surface system brings a changeover to a wintry mix and
then snow. PoPs will generally decrease across the area through
Wednesday as the system continues to move away and a mid level
trough axis pushes east of Wisconsin.

Colder air and moisture wrapped around the departing system will
bring a chance for snow showers to north central Wisconsin into
Friday morning. A surface ridge should then keep things mostly
dry until a mid level short wave in northwest flow and warm
advection bring a chance for light snow on Friday night. Models
showed another surface system strengthening over the northern
Plains on Sunday which could impact the area late in the day, but
its exact path and strength remain uncertain at this point.

High temperatures should be within a few degrees of normal through
the end of the week, before warm advection brings highs in the 40s
to most of the area for the weekend.

.AVIATION...for 18Z TAF Issuance
Issued at 1126 AM CST Mon Feb 27 2017

VFR conditions to prevail for the rest of today into this
evening. Approaching frontal system late tonight will begin to
lower cigs, and move precipitation from southwest to northeast
across the region. Light snow and/or freezing rain may occur for a
few hours over north-central WI late tonight into early Tue
morning, which could impact flat surfaces such as runways. A
period of low level shear conditions is also possible late
tonight over north-central Wisconsin. Lifr/ifr cigs and poor vsbys
are expected to hold tough through much of the day tomorrow with
periods of light rain and drizzle.




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