Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 072332

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

Updated aviation portion for 00Z TAF 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 00Z TAF Issuance
Issued at 410 PM CST Thu Dec 7 2017

An upper level disturbance will bring another round of light
showers or flurries to much of the region tonight into Friday
morning. The next disturbance will bring a more substantial
accumulating snow Friday afternoon into Saturday morning.
Look for VFR CIGS to deteriorate into the MVFR category across
much of the area, with local IFR conditions across the north later
tonight into Friday morning. Snow showers or flurries will be
most numerous across the north tonight into Friday morning, with
flurries across central and east-central Wisconsin after midnight
into the mid morning hours on Friday. The next round of snow
should arrive across the north Friday afternoon, reaching
KAUW/KCWA by mid to late afternoon and at KGRB/KATW/KMTW
by late afternoon or early evening. Snow will continue through
much of Friday evening, then tapering off late Friday night or
early Saturday morning across much of the area. Snowfall totals
of 1 to 3 inches are expected across much of the region.




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