Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 072055

Area Forecast Discussion
National Weather Service Green Bay WI
255 PM CST Thu Dec 7 2017

Forecast discussion for routine afternoon forecast issuance

.SHORT TERM...Tonight and Friday
Issued at 254 PM CST Thu Dec 7 2017

Clouds will be on the increase tonight as a weak trough tracks
through the western Great Lakes region. This system will bring
light snow or flurries as it tracks through, with the best chances
across the far north given the added boost from the Great Lakes.
Snowfall amounts tonight will be fairly light, with a dusting
possible across the far north. Even with clouds in place,
overnight lows will still dip to around 10 across the north, with
middle to upper teens across east-central and far northeast
Wisconsin given the cold airmass in place.

Light lake effect snow showers will be ongoing Friday morning
across the far north. However the bigger concern will be a clipper
system tracking through the region late Friday afternoon. The
system will just be getting into the region by Friday afternoon,
therefore snowfall amounts will be fairly light during this period
of the forecast with up to an inch possible across the far north,
with a dusting possible across central Wisconsin. There is some
concern regarding the amount of moisture this system will have to
work with as PWATs will only be 0.10 to 0.20. However this system
will have a vigorous shortwave and fairly high snow ratios around
20 to 1 so the strong dynamics and efficient use of the moisture
could help it achieve despite meager moisture. Highs Friday will
be a bit warmer with temperatures ranging from the lower 20s
across the north, with upper 20s across east- central Wisconsin.

.LONG TERM...Friday Night Through Thursday
Issued at 254 PM CST Thu Dec 7 2017

The clipper system should be able to produce an inch or two of
snow Friday evening despite little moisture or low level warm
advection. The snow will diminish over all but Vilas county by
late at night. Lake effect snow is then expected across far
northcentral Wisconsin Saturday. Winds are only favorable for
several hours, and the air is quite dry, so only expect a few
inches in Vilas county.

Some light snow is possible during the day Sunday, with another
clipper system Sunday night or Monday. Models have differences in
amount and timing of snow. Additional lake effect snow is possible
behind that system. More opportunities for light snow are expected
towards the end of the week.


.AVIATION...for 18Z TAF Issuance
Issued at 1149 AM CST Thu Dec 7 2017

Mainly VFR conditions this afternoon with high clouds across the
area and low/mid clouds exiting, except over far northern
Wisconsin were MVFR conditions will exist at times. This evening,
mid- clouds gradually return, followed by low clouds overnight
and into Friday morning. Winds veer slightly more NW across Lake
Superior early Friday morning and could bring some light lake
effect snow showers across northern Vilas County. Otherwise, light
snow showers or flurries are possible across central and north-
central Wisconsin ahead of a clipper system Friday morning, but
most of the area will remain dry through the TAF period ending at
Noon Friday. This clipper is expected to bring widespread snow to
the area late Friday afternoon and Friday evening which would
result in extended IFR conditions.



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