Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 190809

Area Forecast Discussion
National Weather Service Green Bay WI
309 AM CDT Mon Mar 19 2018

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Tuesday
Issued at 309 AM CDT Mon Mar 19 2018

After a mild weekend, a cold front passage last night will bring
cooler temperatures on northeast winds for the start of the new
work week. The forecast area will be caught between high pressure
to the northeast of the Great Lakes and the slow moving trough
system over the northern plains. The primary issue will be cloud
cover and temperatures as drier air will be feeding into the area.

Early this morning, satellite imagery shows mid level clouds over
the forecast area, while lower level clouds were more widespread
over the northern plains with the weak trough system. The mid
level clouds were gradually thinning as well early this morning,
so a decreasing trend in clouds appears ok for today. Anticipate
mid level clouds will continue to stream across the area through
Tuesday while drier low levels will confine lower level system
clouds to the west. These cloud trends will cause some challenges
to max temperature forecasts each today and Tuesday. More clouds
are expected over western Wisconsin, putting central Wisconsin
under a more variable cloud cover. March sun and snow less inland
regions from the bay and Lake may exceed most guidance today.

Progs suggest the weakening upper trough system shifts eastward
Tuesday. In addition, H850 temperatures will continue to cool
Tuesday, resulting in the potential of lake clouds developing
along with a diurnal increase of clouds. The potential of more
clouds will lead to cooler max temperatures Tuesday compared to

.LONG TERM...Tuesday Night Through Sunday
Issued at 309 AM CDT Mon Mar 19 2018

Forecast concerns mainly revolve around precip chances during the
Friday into Saturday period.  In general, the medium range models
show a storm track remaining south of the region.  Models have also
trended slightly further south with the track of a low pressure
system on Fri-Sat, leaving northern WI under greater influence of a
Hudson Bay High pressure system.  Will continue to rely on a general
model blend for this part of the forecast.

Tuesday night through Wednesday night...Sheared shortwave energy
will be slowly migrating across the state on Tuesday night and
Wednesday.  Cloud cover will be plentiful during this period, with
progged soundings showing deep saturation above 700mb for most
locations.  The column will likely struggle to saturate below around
10 kft, due to dry NE winds emanating out of a high pressure to the
north.  As a result, models show most of the light precip chances
remaining over western WI and MN.  The lone exceptions could be the
Lake Michigan shoreline, where instability may be just sufficient
for a few flurries, and also possibly far north-central WI, closer
to the more robust low level moisture. Though some cloud cover will
likely stick around on Wednesday night, the shortwave energy will be
departing to the east, so should see some clearing take place.  With
the cloud cover and NE winds, temps will likely be chilly over this

Rest of the forecast...Mostly clear conditions are likely to return
to the region on Thursday and Thursday night, thanks to building
heights aloft and high pressure at the surface.  The next low
pressure system will be moving across the central Plains on Friday
and into the Ohio Valley on Saturday.  Will see mid and high clouds
increase as this system passes, and a chance of snow will likely
remain over central and east-central WI on Fri night and Saturday,
but chances have diminished over the past 24 hours.  Cool and dry
weather returns on Sunday.

.AVIATION...for 06Z TAF Issuance
Issued at 1200 AM CDT Mon Mar 19 2018

VFR mid clouds are expected in most areas through noon Monday followed
by clearing. There could be some MVFR ceilings mostly north of a Wausau
to Iron Mountain line for a while late tonight and early Monday.



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