Small Craft Advisory 69, NWS Milwaukee, WI

628 
WHUS73 KMKX 180820
MWWMKX

URGENT - MARINE WEATHER MESSAGE
National Weather Service Milwaukee/Sullivan WI
320 AM CDT Tue Sep 18 2018

...Gusty Northeast Winds and High Waves This Morning...

LMZ643-644-181630-
/O.EXT.KMKX.SC.Y.0069.000000T0000Z-180918T1800Z/
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
320 AM CDT Tue Sep 18 2018

...SMALL CRAFT ADVISORY NOW IN EFFECT UNTIL 1 PM CDT THIS
AFTERNOON...

The Small Craft Advisory is now in effect until 1 PM CDT this
afternoon. 

* WINDS: North to northeast 15 to 20 knots with frequent gusts up
  to 25 knots, diminishing to 10 to 20 knots by late morning. 

* WAVES: 4 to 5 feet subsiding to 2 to 3 feet by early afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 21 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners...especially those operating smaller
vessels should avoid navigating in these conditions.

&&

$$
MRC

www.weather.gov/mkx

522 
WHUS73 KMKX 181417
MWWMKX

URGENT - MARINE WEATHER MESSAGE
National Weather Service Milwaukee/Sullivan WI
917 AM CDT Tue Sep 18 2018

...Gusty Northeast Winds and High Waves This Morning...

LMZ643-644-181800-
/O.CON.KMKX.SC.Y.0069.000000T0000Z-180918T1800Z/
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
917 AM CDT Tue Sep 18 2018

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 1 PM CDT THIS
AFTERNOON...

* WINDS: North to northeast 15 to 20 knots will continue to
  diminish this morning.
  

* WAVES: around 4 feet subsiding to 2 to 3 feet by early 
  afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 21 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners...especially those operating smaller
vessels should avoid navigating in these conditions.

&&

$$


www.weather.gov/mkx

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
623 PM CDT Mon Sep 17 2018

.UPDATE...

Convection continues to percolate across central Wisconsin along
and ahead of a frontal boundary. As the sun sets over the next
hour or two, we should see a fairly steady decline in both the
strength and coverage of this thunderstorm activity. A few
showers or thunderstorms may still make it into the northern and
western portions of the forecast area, though.

More widespread activity is expected to develop later tonight
across Iowa and southern Minnesota, and will move into the region
during the pre-dawn hours on Tuesday.

&&

.AVIATION(00Z TAFS)...

A broken area of thunderstorms to the north and west of the terminals
should dissipate this evening with sunset, though a few showers
or widely scattered thunderstorms may affect KMSN and points west
later this evening. More widespread activity is then expected to
develop across Iowa and southern Minnesota overnight, moving east
into the region tomorrow morning before daybreak. Conditions are
expected to fall to MVFR with this activity, with periods of IFR
possible.

Winds tonight will become northerly and then northeasterly as a
front sweeps south through the area. Winds will be somewhat light
and variable through the day Tuesday, but generally speaking will
remain from the northeast.

&&

.PREV DISCUSSION... (Issued 203 PM CDT Mon Sep 17 2018)

DISCUSSION...

Tonight and Tuesday...Forecast confidence is medium to high:

Deep moisture will continue to increase across southern Wisconsin
this afternoon and evening. A couple areas of forcing will bring
on and off shower/storm chances to the area this evening into
Tuesday morning. Models continue to suggest that each round will
generally be winding down as it enters the area, with locations
from Madison westward having the best chance to see
showers/storms.

Meanwhile, a backdoor cold front will drop into the area tonight,
getting stuck around the WI/IL border for Tuesday. Temps will thus
be cooler tomorrow, but still a few degrees above normal away from
Lake Michigan. Should be mostly cloudy tomorrow as well, which
will help keep temps down.

There will likely be a lull in precip most places later Tue
morning into the afternoon. Could see activity pick up again in
the west by late afternoon.

Tuesday night through Wednesday...Forecast confidence is medium.

A weak frontal boundary will linger over the area, stretching back
to a parent low pressure over the Central Plains. High pressure
will set up over the eastern half of the Great Lakes, stretching
north into Canada. This will be a rather stationary pattern during
this time and it may help to keep eastern Wisconsin on the dry
side. We should see occasional showers and storms fire over
southern MN and nrn IA, then roll southeast and threaten the
forecast area. There is uncertainty Tuesday night due to some
decent capping in the low levels, but there may be enough energy
to support elevated activity.  As we get into Wednesday, we see a
better chance of rain spreading in after sunrise.

Wednesday night through Thursday night...Forecast confidence is
medium.

The low pressure out west will begin to move northeast toward the
Great Lakes and strengthen, resulting in an increasing low level
jet. This should give the stationary front a shove north. The
interaction of the boundary and an invigorated LLJ should result
in a better chance of showers and storms Wed night. It looks like
the front will push far enough north on Thursday to take the
focus of the rain north of the CWA in the morning. 925mb temps
warm into the lower and mid 20Cs, so we could see temps climbing
into the mid and upper 80s across the southeast. As the low passes
by to the north and east, a trailing cold front will push through
the area during the afternoon and evening. There does appear to
be enough deep layer shear and instability for there to be a
threat for severe storms Thursday afternoon/evening.

Friday through Sunday...Forecast confidence is medium.

A cooler and drier airmass will plow in here for Friday. The EC
had been clipping southern Wisconsin with some rain for Saturday
as it took a stronger more northern track to a system passing by
to the south. The EC has come in dry, as has the GFS and the
Canadian for Saturday. So, will go with a dry weekend with highs
in the 60s to around 70.  Ahhh...

AVIATION(18Z TAFS)...

Quiet weather will continue into early evening. Attention then
turns to a couple rounds of weakening showers/storms approaching
from the west mid-evening into Tuesday morning. Areas from Madison
westward have a good shot at seeing showers and storms, with less
confidence farther east. Models continue to drop ceilings later
tonight into Tuesday as a cooler airmass drops pushes into the
area. Looks like mainly MVFR ceilings, though IFR could happen for
a while. Will have to keep an eye on upstream observations.

There will be lower chances for precip late Tue morning into the
afternoon, with ceilings expected to improve by afternoon.

MARINE...

Northerly winds will build higher waves tonight into early
Tuesday, with wave heights approaching 4 feet. Currently looks
like conditions should stay just below Small Craft Advisory
criteria. Could see winds approach advisory levels on Thursday
ahead of an approaching front.

Thunderstorm chances will return tonight and then persist through
Thursday.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

Update...Boxell
Tonight/Tuesday and Aviation/Marine...Boxell
Tuesday Night through Monday...99

Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
317 PM CDT Mon Sep 17 2018

WIZ046-047-051-052-056>060-062>072-182030-
Marquette-Green Lake-Fond Du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
317 PM CDT Mon Sep 17 2018

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

.DAY ONE...Tonight

There is a chance of thunderstorms tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Monday

There is a chance of thunderstorms at times from Tuesday through
Thursday night. Locally heavy rainfall is possible, especially
over parts of south central Wisconsin.

Strong to severe storms will be possible on Thursday as a cold
front sweeps through the area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through at least Tuesday.

LMZ643>646-182030-
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-
317 PM CDT Mon Sep 17 2018

This Hazardous Weather Outlook is for portions of Lake Michigan.

.DAY ONE...Tonight

There is a chance of thunderstorms tonight.

Northerly winds and waves will approach small craft levels north
of Port Washington tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Monday

Increasing southerly winds may result in a small craft advisory
Thursday into Thursday night. There are chances for thunderstorms
Tuesday through Thursday night.

www.weather.gov/mkx