Winter Weather Advisory 1, NWS Milwaukee, WI

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
Issued by National Weather Service Green Bay WI
604 AM CST Fri Jan 1 2021

Updated aviation portion for 12Z TAF issuance

.SYNOPSIS...
Issued 323 AM CST Fri Jan 1 2021

A round of light snow this afternoon and evening, mainly over the
southeast part of the state, then a return to relatively quiet
weather with above normal temperatures.

Split upper flow will persist across North America throughout the
forecast period. The northern stream will remain low amplitude,
and primarily across Canada. That will prevent any intrusion of
cold air from high latitudes into the area, and result in above
normal temperatures. The southern stream will be highly amplified
at the start of the period but gradually flatten for several
days before probably reamplifying a little late in the period. A
mature southern stream cyclone will track just close enough to the
area to produce some light snow this afternoon into tonight. A
second system may just graze the area Saturday night, then dry
weather is expected until at least late next week. The total
precipitation for the period will probably end up below normal.
&&

.DISCUSSION...
Issued 323 AM CST Fri Jan 1 2021

The main forecast issue this morning was fine tuning the snowfall
potential with the mature cyclone passing southeast of the area
late today and tonight. 00Z RAOBS from across the region showed a
lot of dry air will need to be overcome before precipitation can
begin, so tried to slow down the arrival of the snow, especially
north of the Illinois border areas. The model precipitation
forecast looked a little high, especially given the dry air and
the fact that the best dynamics will be passing well south of the
area. Kept 1-3 inch snowfalls going over the SW part of the state,
but trimmed amounts a little on the NW edge of the precipitation
shield. Amounts may need to be edged up a little more in Kenosha
county, but it seemed wise to wait and see how far/fast the
precipitation shield advances north this morning prior to doing
that. Although mixed precipitation is possible at times, forecast
soundings suggest snow will be the dominant type.

The standard NBM forecast initialization grids seemed reasonable
for the rest of the forecast, so no significant changes were
necessary.
&&

.AVIATION...for 12Z TAF Issuance
Issued 602 AM CST Fri Jan 1 2021

Widespread low stratus/fog covered the region this morning, with
IFR/LIFR conditions at most inland locations. East flow off the
relatively mild waters of Lake Michigan was resulting in higher
ceilings and vsbys near the lakeshore, with mainly MVFR
conditions. The stratus/fog will prevail through much of the
morning.

Low pressure tracking southeast of the region will bring snow to
southeast WI this afternoon/evening, with associated IFR
conditions. As the low exits to the east, gradually improving
conditions are expected overnight. Partial clearing could occur
in eastern WI Saturday morning.
&&

.MARINE...
Issued 323 AM CST Fri Jan 1 2021

Winds and waves will increase over southern Lake Michigan today as
the cyclone tracks toward Lake Erie. Winds will remain below gale
force, but a Small Craft Advisory will be needed for the southern
3 MKX NSH zones for this afternoon into tonight.
&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ644-LMZ645-LMZ646...2 PM Friday to 4
     AM Saturday.

&&

SYNOPSIS.......JS
DISCUSSION.....JS
MARINE.........JS
AVIATION.......TSK

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Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
Issued by National Weather Service Green Bay WI
407 AM CST Fri Jan 1 2021

WIZ046-047-051-052-056>060-062>072-021200-
Marquette-Green Lake-Fond du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
407 AM CST Fri Jan 1 2021

This Hazardous Weather Outlook is for portions of east central
Wisconsin, south central Wisconsin and southeast Wisconsin.

.DAY ONE...Today and Tonight

Roads across southeast Wisconsin could become slippery this
afternoon and evening due to snow. One to three inches of snow is
expected.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to forward snowfall measurements to the
National Weather Service.

LMZ643>646-021200-
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
North Point Light to Wind Point WI-
Wind Point WI to Winthrop Harbor IL-
407 AM CST Fri Jan 1 2021

This Hazardous Weather Outlook is for the nearshore waters from
Sheboygan Wisconsin to Winthrop Harbor Illinois.

.DAY ONE...Today and Tonight

Gusty northeast winds and building waves will create conditions
hazardous to small craft this afternoon into tonight, mainly
south of Port Washington.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The probability for widespread hazardous weather is low.

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-021200-
Lake Michigan Michigan City IN to St. Joseph MI 5 NM offshore to
mid-line of lake.-
Lake Michigan from Seul Choix Point to Rock Island Passage 5NM
offshore to Mid Lake-
Lake Michigan South of a line from Seul Choix Point to the
Mackinac Bridge and North of a line from Charlevoix MI to South
Fox Island 5NM offshore-
Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to
mid lake-
Lake Michigan from Point Betsie to Manistee MI 5NM offshore to
Mid Lake-
Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM
offshore to mid lake-
Lake Michigan from Sturgeon Bay to Two Rivers WI 5NM offshore to
Mid Lake-
Lake Michigan from Two Rivers to Sheboygan WI 5NM offshore to Mid
Lake-
Lake Michigan from Sheboygan to Port Washington WI 5NM offshore
to Mid Lake-
Lake Michigan from Port Washington to North Point Light WI 5NM
offshore to Mid Lake-
Lake Michigan from North Point Light to Wind Point WI 5NM
offshore to Mid Lake-
Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Wilmette Harbor to Michigan City in 5NM
offshore to Mid Lake-
Lake Michigan from Pentwater to Manistee MI 5NM offshore to Mid
Lake-
Lake Michigan from Whitehall to Pentwater MI 5NM offshore to Mid
Lake-
Lake Michigan from Grand Haven to Whitehall MI 5NM offshore to
Mid Lake-
Lake Michigan from Holland to Grand Haven MI 5NM offshore to Mid
Lake-
Lake Michigan from South Haven to Holland MI 5NM offshore to Mid
lake-
Lake Michigan from St Joseph to South Haven MI 5NM offshore to
Mid Lake-
407 AM CST Fri Jan 1 2021

This Hazardous Weather Outlook is for the open waters of Lake
Michigan.

.DAY ONE...Today and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

No hazardous weather is expected at this time.

www.weather.gov/mkx

SPECIAL WEATHER STATEMENT
National Weather Service MILWAUKEE/SULLIVAN WI
Issued by National Weather Service Green Bay WI
619 AM CST Fri Jan 1 2021

WIZ046-047-051-052-056>060-062>072-011500-
Marquette-Green Lake-Fond du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
Including the cities of Montello, Westfield, Oxford, Neshkoro,
Endeavor, Berlin, Princeton, Markesan, Fond Du Lac, Plymouth,
Sheboygan Falls, Howards Grove, Oostburg, Baraboo, Reedsburg,
Prairie Du Sac, Sauk City, Portage, Columbus, Lake Wisconsin,
Lodi, Beaver Dam, Waupun, Mayville, West Bend, Germantown,
Hartford, Mequon, Cedarburg, Grafton, Dodgeville, Mineral Point,
Barneveld, Madison, Watertown, Fort Atkinson, Jefferson,
Waukesha, Brookfield, New Berlin, Menomonee Falls, Muskego,
Milwaukee, Darlington, Shullsburg, Benton, Belmont, Argyle,
Blanchardville, Monroe, Brodhead, Janesville, Beloit, Whitewater,
Delavan, Elkhorn, Lake Geneva, East Troy, Racine, and Kenosha
619 AM CST Fri Jan 1 2021

...AREAS OF FREEZING FOG AND SLICK ROADS THIS MORNING...

Freezing fog will lead to scattered icy spots on area roads early
this morning. The fog may be locally dense, with visibilities of
a half mile or less.

Early morning travelers should be alert for locally hazardous
driving conditions. Be prepared for reduced visibilities and icy
roads. Slow down and keep a safe distance from other vehicles.

Kieckbusch