Small Craft Advisory 106, NWS Milwaukee, WI

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1119 AM CST Fri Nov 29 2019

.UPDATE...Patchy light snow and rain is redeveloping just to the
west of south central Wisconsin late this morning. Surface temps
slow to warm due to widespread thick cloud cover and northeast
surface winds. With upstream warm air and moisture advection
clipping our area, wl continue small chances for light
precipitation this aftn.

&&

.AVIATION(18Z TAFS)...Mix of MVFR and IFR ceilings will persist
most areas into tonight. Expect an area of mixed precipitation to
spread across southern WI later tonight into Saturday morning
resulting in widespread IFR ceilings and at least MVFR
visibilities. East wind gusts will increase to 25 to 35 knots on
Saturday.

&&

.PREV DISCUSSION... (Issued 950 AM CST Fri Nov 29 2019)

UPDATE...Surge of mid-level warm air advection and weak low
pressure wave brought a period of mostly light snow to northwest
CWA last several hours, with patchy drizzle/freezing
drizzle/flurries elsewhere. Latest radar imagery showing light
snow rapidly diminishing in the northwest, but lingering weak
isentropic upglide may produce a little more drizzle or light snow
today.

MARINE...Weaken high pressure over the area will result in
lighter, mostly ENE winds today. Still expect strengthening east
winds tonight through Saturday night as low pressure develops in
the central Plains and moves toward the Western Great Lakes. Gale
Watch currently in effect will likely be upgraded to a Gale
Warning for most of the lake this afternoon.

PREV DISCUSSION... (Issued 550 AM CST Fri Nov 29 2019)

UPDATE...

Pockets of freezing drizzle/light snow continue across parts of
the CWA. Chances will continue through this morning, however as
temperatures warm we will see precipitation turn mostly to
drizzle. Overall we should expect precipitation to mostly end by
the late morning early afternoon prior to the system expected to
move in tonight.

AVIATION(12Z TAFS)...

Pockets of freezing drizzle/light snow continue across parts of
the region but do not look likely to cause much if any concerns
through this morning. MVFR CIGS will continue through most of
the morning before likely falling to IFR for most of the TAF
period. By the evening we will start to see our next system push
in. This will bring precipitation into the region perhaps lowering
VSBYS to MVFR with CIGS as low as LIFR. The overnight period
could feature some mixed precipitation including sleet and slight
freezing rain potential in addition to rain and snow. However,
little to no ice accumulation is expected with rain expected the
rest of the day Saturday as the system fully pushes in.

PREV DISCUSSION... (Issued 427 AM CST Fri Nov 29 2019)

SHORT TERM...

Today through Tomorrow...Forecast Confidence is Medium...

Now an through much of the morning we expect fairly weak forcing
through the region, but primarily further to the western parts of
the CWA. The forcing will primarily be in the mid levels where
some WAA will be present. This could yield some light
precipitation across southern Wisconsin through the morning
possible into the afternoon. Most of the region has lost
saturation in the DGZ which suggests we could see some freezing
drizzle through the morning with any showers, prior to the surface
warming up later this morning. We have seen some some freezing
drizzle and snow this morning suggesting ice has not been
completely lost. With forcing this weak we should not expect
anything significant but the potential for freezing drizzle could
mean some slick spots in some areas.

The main concern will be later in this evening when the next
system is expected to begin pushing in. The initial forcing for
this system will be associated with a few shortwaves ahead of the
upper low and strong low to mid level WAA. This should bring in
mostly rain and some snow, though this snow will not accumulate
much, if any. There will be periods where freezing rain and sleet
become a possibility as well mainly overnight and through the
morning where the WAA will likely cause some precipitation type
concerns for a brief period. Into the afternoon the region should
warm enough to where rain becomes the predominant precipitation
type.

Saturday afternoon and evening will become quite breezy with
southeasterly winds around 25 to 30 mph with with gusts from 35
to 40 mph at times. this will bring waves up to 8 to 10 feet along
the the shoreline. Thus a Lakeshore Flood Advisory has been issued
for the nearshore counties from Saturday afternoon through
Saturday evening.

LONG TERM...

Saturday night through Sunday night...Forecast Confidence is
Medium

We start the long term period with the surface low shifting due
east across IA and into IL. Models haven't changed much with the
track and keep the vertically stacked core of the low over
northern IL during this period. Strong WAA on Saturday will have
brought in a +3C to +6C warm nose aloft and this carries down to
the surface with temps in the mid to upper 30s. This will keep the
precip type all liquid for much of the area as the bulk of the
forcing is overhead Sat night through Sun morning. Locations
across central WI will be in the transition zone with slightly
cooler temps aloft and could see more of rain/snow mix during the
overnight period. A band of moderate to heavy rain is expected to
develop along and ahead of the cold front, which moves through
overnight. It's possible we see a brief break in precip Sunday
morning as the dry slot gets wrapped up into the system. But this
won't last long with the low shifting into northern IN by the
afternoon hours, expect precip to start to fill back in from west
to east. This should start out as a mix of rain/snow then as
colder air continues to filter in change over to all snow.

Looking at amounts, the warmer air will keep SLR's on the low side
Saturday night into Sunday morning. So locations in central WI
that do end up with a rain/snow mix should see generally less than
1 inch. Then as we begin to transition over to all snow Sunday
afternoon/evening a dusting to an inch is possible with the higher
amounts focused mainly over central WI. Storm totals 1-2 inches
north with a trace to half an inch possible, which lines up
closely with the 50th percentile. The 75th percentile would bring
the 1 inch line down to I-94 and could see that happening if
precip lingers Sunday evening. All precip should be out of here by
Monday morning.

Monday through Friday...Forecast Confidence is Medium.

Highs for much of the extended period stay in the mid to upper 30s
as we remain under a general W/NW flow regime next week. A quick
moving clipper system on Tuesday could bring a brief rain/snow mix
but drier air in place could really limit precip chances. So, for
now have kept this out of the forecast. Ridging will build
eastward into the south-central US and provide a break in precip
until late next week.

AVIATION(09Z TAFS)...

There is still a  chance for light freezing rain/drizzle to occur
from now to the mid morning though confidence remains low, Some
drizzle or light rain may occur through the day, as surface
temperatures warm above freezing.

MVFR ceilings around 2000 feet, dropping to around 1500 feet at
times, should remain this morning, before falling to around or
under 1000 feet by midday. Ceilings should then fall to around
500 feet tonight, as the mixed precipitation moves into the area.
Visibility values should drop to MVFR category with the
precipitation Friday night.

Winds will be light and variable this morning, becoming easterly
by late morning and afternoon. Winds will become southeast tonight
and become gusty.

MARINE...

Winds will be light from the east this morning and continue
through much of the day today as they slightly turn more to the
southeast. They will steadily increase from the southeast as the
system approaches from the west.

This will cause concerns for Small Craft Advisory conditions by
Saturday morning with Gale force winds across the northern
nearshore areas and the open waters by Saturday afternoon. Thus a
small craft will be needed with a Gale Watch in effect for the
areas mention beginning at 18z. The small craft will be needed
for winds and especially waves, with waves approaching 8 to 10
feet in the nearshore.

Winds will mostly decline across the southern half of the lake by
late Saturday evening though strong east to northeast winds will
continue across the northern half through 00z Monday. Winds will
slowly diminish Sunday evening as the system pulls out and winds
turn to the north.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Lakeshore Flood Advisory from noon Saturday to midnight CST
     Saturday night for WIZ052-060-066-071-072.

LM...Gale Watch from Saturday afternoon through Saturday evening for
     LMZ080-669-671-673-675-777-779-870-872-874-876-878.

     Gale Watch from Saturday afternoon through Sunday afternoon for
     LMZ261-362-364-366-563-565-567-868.

     Gale Watch from Saturday afternoon through Saturday evening for
     LMZ643-644.

&&

Update...MBK
Today/Tonight and Aviation/Marine...MBK
Saturday THROUGH Thursday...Stumpf

Hazardous Weather Outlook...UPDATED
National Weather Service Milwaukee/Sullivan WI
1210 PM CST Fri Nov 29 2019

WIZ046-047-051-052-056>060-062>072-301815-
Marquette-Green Lake-Fond du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
1210 PM CST Fri Nov 29 2019

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

.DAY ONE...This Afternoon and Tonight

A system approaching the area tonight will result in a wintry mix
of rain, snow, and sleet for all of southern and central
Wisconsin. Expect some slippery spots on area roads overnight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The wintry mix continues for central Wisconsin through Saturday
morning, while a transition over to all rain will occur for the
remainder of the area. Some slippery spots are possible on roads
Saturday morning.

A period of strong onshore winds and high waves Saturday
afternoon and evening will lead to lakeshore flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

LMZ643>646-301815-
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-
1210 PM CST Fri Nov 29 2019

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

.DAY ONE...This Afternoon and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Breezy southeast winds and building waves are expected Saturday
into Saturday evening. Gales to 35 knots are possible and a Gale
Watch has been issued for locations north of North Point Light.

Brisk northerly winds and building waves will return for Sunday
afternoon into Monday. A Small Craft Advisory may be needed.

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-301815-
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-
1210 PM CST Fri Nov 29 2019

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

.DAY ONE...This Afternoon and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Another low pressure system crossing the region will bring a
chance for easterly gales Saturday into Sunday morning and
northerly gales Sunday afternoon and night. Waves will build
during this period as well. A Gale Watch has been issued for all
of Lake Michigan for Saturday through Sunday.

www.weather.gov/mkx

MBK