Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 161034

Area Forecast Discussion
National Weather Service Green Bay WI
534 AM CDT Fri Mar 16 2018

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Saturday
Issued at 211 AM CDT Fri Mar 16 2018

Early this morning, weak radar returns and observations over
northern Door County were reporting light snow showers or
flurries. The light precipitation is associated with a lingering
weak trough and northerly fetch off the Great Lakes. Clouds were
also brushing over northern Door County, otherwise clear skies
light winds over the rest of the area were allowing temperatures
to fall, especially across the snow covered north. Forecast focus
during this period are minor cloud trends today and temperatures
today through Saturday.

High pressure will dominate the region through Saturday with
sunny days and clear nights. Only exception is perhaps some mid to
high level clouds brushing over the south half of the state today
due to the passing storm system over the lower to mid mississippi
valley region. Its also possible some of the strato cu clouds
extending from central Upper Michigan to far northern Door County
to eastern Lower Michigan early this morning may make a run
toward the lake shore counties today due to an easterly surface
component. This easterly component will drift southward along the
lakeshore as the high pressure ridge axis shifts south. Much of
Door County surface winds turn southwest later today into tonight.

Will go with persistent cold low temps again tonight across the
north with the clear skies, light winds and dry air mass.

After a cold start Saturday morning, Temperatures begin to modify
to milder levels. Despite the cold dry air mass over the area the
last few days, daytime highs were not having much problem reaching
near normal levels over the snow less regions. Light northeast
winds return for Saturday, so slightly cooler readings expected
along the shoreline. Its also possible lake clouds may again
brush the shoreline for Saturday.

.LONG TERM...Saturday Night Through Thursday
Issued at 211 AM CDT Fri Mar 16 2018

The medium range models continue to advertise a quiet weather
pattern over the next week, thanks in part to a blocking mid-level
ridge positioned just upstream of the western Great Lakes, and also
a storm track well south of the region as well.  Will continue to
follow a general model blend for this part of the forecast.

Saturday night through Sunday night...With a dominant mid-level
ridge located over the northern Plains, ample dry air through the
column will ensure mostly clear conditions continue on Saturday
night. Will side with the colder guidance for the snow covered
areas.  Cloud cover should continue to be minimal on Sunday.
However, models point towards a back door cold front will drop
across the region on Sunday afternoon or Sunday evening depending on
the location.  This front will bring cooler temperatures and breezy
conditions to the region, in particular for northeast WI, where
wind trajectories will originate off the Bay and Lake.

Rest of the forecast...Northeast winds will continue to provide
chilly and blustery weather on Monday.  Mid-level ridging gradually
breaks down on Tuesday and Wednesday.  Should see more in the way of
cloud cover arrive as this occurs, but with a storm track that will
be south of the region, and residual dry air in the low levels,
precip chances look very low.  Some moderation of temps appears
possible late in the work week.

.AVIATION...for 12Z TAF Issuance
Issued at 534 AM CDT Fri Mar 16 2018

High pressure settled over the region will produce VFR
conditions with light winds today into Saturday for most areas.
Patchy MVFR or lower end VFR clouds may brush along parts of the
Lake Michigan shore at times today and again on Saturday. Mid to
high level clouds may slide over the south half of the state later
today into Saturday.



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