Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 301533

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1033 AM CDT FRI SEP 30 2016

.AVIATION/18Z TAFS/...Stacked/cutoff low vcnty srn IN continues to
pivot moisture westward into srn WI. Embedded spokes of energy
result in an uptick in shra across the area. Low cigs and some lwr
vsbys are accompanying this moisture feed and the moisture from
the lake as well. However vsbys where reduced are mostly of the
MVFR variety. Most cigs likely to be IFR category but a few are
LIFR and some are sneaking into the MVFR category. So some
variability out there. This is expected to persist for much of
this forecast period as additional rounds are forcing result in
more shra. Pressure gradient remains supportive of gusty northeast
winds with the highest gusts closer to the lake.



.MARINE...Expect gusty northeast winds to continue into tonight
causing high waves of 3 to 6 feet. Winds and waves have subsided
slightly in last 12-24 hours and should continue to slowly subside
through Saturday morning as pressure gradient slackens due to
approaching low pressure from the south. Wilmette Buoy which is
about 30 miles SSE of Wind Point measuring waves around 5 feet.
Light fog will accompany the occasional showers and drizzle today
into tonight as well. Status quo regarding ongoing Small Craft



.PREV DISCUSSION... /Issued 400 AM CDT FRI SEP 30 2016/

TODAY AND TONIGHT...Forecast confidence high.

Stratus clouds have overspread srn WI along with a few showers over
far se WI. Additional rain showers over lower MI will be moving
across Lake MI and affecting far ern WI toward sunrise. A lobe of
PVA is currently pivoting wwd through the area and aiding the
development of the showers. PVA and moisture transport will increase
toward late afternoon and through the night as the upper low moves
nwd through IN tonight. PWs will increase to 1.4 inches and forecast
soundings do eventually saturate. Overall for today isolated to
scattered showers will prevail with rain becoming likely over ern WI
late in the day. Likely to categorical PoPs for tonight. Temps have
been mild early this morning but will not rise too much today given
the clouds and scattered showers.

SATURDAY THROUGH SUNDAY NIGHT...Forecast Confidence Is Medium.

Models continue to show the closed 500 mb low shifting slowly
northward across northern Indiana Saturday, before moving into
southeast lower Michigan Saturday night. The closed low then
slides off to the east Sunday and Sunday night. There is a little
variation among the models with the exact 500 mb low track.

Several 500 mb vorticity maxima, with differential cyclonic
vorticity advection, should combine with decent column moisture to
result in a good shot at rain showers Saturday morning in the
eastern counties. This does continue into the afternoon. May need
to raise PoPs more for Saturday across the area, if the wet look
of the models continues.

There is some drying in the air column Saturday afternoon, which
may limit the areal coverage of any showers. Did not add thunder
for Saturday afternoon and evening in the far southeast counties,
as mean layer CAPE values are quite low.

Kept PoPs mainly in the eastern counties Saturday night into
Sunday morning, as the 500 mb low starts to push east of the area.
Weak high pressure should bring quiet weather for Sunday afternoon
and night, with drier air working into the area. Highs should
remain near seasonal normals, with mild lows.

MONDAY THROUGH THURSDAY...Forecast Confidence Is Medium.

Dry southeasterly flow Monday into Tuesday night should bring a
period of quiet weather to the area. Temperatures may rise a bit
during this time, reaching the lower 70s inland on Tuesday.
Onshore winds should keep the coolest temperatures near the lake.

The next system should then move east into the region Wednesday
into Thursday. A fairly strong cold front is shown by the
ECMWF/GFS to move east into the region Wednesday night, exiting on
Thursday. This is accompanied by broad cyclonic flow at 500 mb, as
a deep 500 mb low remains over far northern Minnesota.

Area forecast soundings show rather weak instability Wednesday
afternoon and evening across the area. For now, will continue to
mention PoPs for showers and slight chances for thunderstorms
for Wednesday into Wednesday night, with showers lingering
Thursday. The mild temperatures should remain across the area.

AVIATION/12Z TAFS/...Cigs of 1-3 kft this morning will continue to
drop to 600-900 feet and eventually 500 feet or lower as the more
steady rain arrives late today and tonight. Mvfr vsbys are expected
over ern WI with the rain this afternoon but the overall saturating
of the atmosphere will lead to widespread light fog and mvfr vsbys
tonight. Areas of 2sm br are possible.

MARINE...A Small Craft Advisory continues until 09z Sat. Brisk nely
winds today will gradually weaken tonight into Sat. Thus high wave
heights of 4-6 feet will subside to 2-4 feet early Sat am.


.MKX Watches/Warnings/Advisories...
LM...SMALL CRAFT ADVISORY until 4 AM CDT Saturday for LMZ643>646.


Saturday THROUGH Thursday...Wood is the U.S. government's official web portal to all federal, state and local government web resources and services.