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Area forecast discussion 
National Weather Service Milwaukee/Sullivan WI
942 PM CDT sun Jul 27 2014

Update...-shra continue to diminish as secondary front/wind shift
slides south of area. Overnight temperatures appear in good shape. Will
keep p/cloudy wording through the late evening...however drier air
overwhelming low level moisture and may result in M/clear skies
for the late night.

&&

Aviation/06z tafs/...may still be a period of MVFR ceilings at eastern
taf sites as cooler air surges southward. However drier air in the low
levels also surging southward preventing significant low cloud
development. Will continue to monitor but leaning toward more
optimistic ceilings as 1000-850mb winds remain more northerly
overnight as cool air settles in.

&&

Marine...gusty north winds behind a departing cold front are expected
to continue into Monday before diminishing. These winds will build
waves to 3 to 7 feet. Hence the Small Craft Advisory will remain
in effect.



&&

Beaches...winds have now veered more northerly and are expected
to remain north into Monday afternoon. Wind speeds of 10 to 20
knots with occasional higher gusts will continue to generate high
waves and a higher liklihood of dangerous currents along Lake
Michigan beaches. Hence the beach hazard statement for a high swim
risk will remain in effect through Monday.

&&

Previous discussion... /issued 400 PM CDT sun Jul 27 2014/

Short term...

Tonight and Monday...forecast confidence...high

Showers and storms will wind down quickly this evening as daytime
heating is lost. Clouds will then diminish through the evening and
into tonight as drier air pushes in from the north.

Expect mostly sunny skies Monday as high pressure pushes into the
region...with maybe scattered afternoon cumulus. Highs will be a few
degrees below normal...making for a very pleasant day.

Tuesday and Wednesday...forecast confidence...high

The middle/upper trough continues to dig across the eastern U.S.
Tuesday and Wednesday as several weak shortwaves rotate around the
main upper low centered near or just south of James Bay Canada.
500 mb temperatures are around -15 and -16 Tuesday but begin to
slowly moderate on Wednesday. However instability remains as low
levels also begin to warm a little. 700 mb upward motion exists
both Tuesday and Wednesday afternoon as the weak shortwaves
coincide with diurnal heating. 850-700 mb relative humidity is rather high...
especially at 850 mb. Zero to 1 km mixed layer cape is around 150
to 200 joules/kg and equilibrium levels near 20 thousand feet.
Therefore scattered diurnal showers...should occur both Tuesday
and Wednesday.

High pressure becomes centered over the eastern plains and upper
Mississippi Valley. Morning lows will depend on how much clouds
dissipate overnight.

Long term...

Thursday and Friday...forecast confidence...high

Continued very good agreement in the GFS/European model (ecmwf) and dgex. The
eastern U.S. Trough becomes more broad and begins to retrograde
a little toward the west. This keeps more diurnal precipitation
chances and continues the rather cool Summer temperatures.

Mainly the GFS brings a weak shortwave into Wisconsin from the
north Thursday night and Friday with the GFS generating a little
precipitation into Thursday night and Friday morning...along with
the afternoon diurnal increase that is on both the GFS and European model (ecmwf).

Very little surface pressure gradient across much of the U.S. By
this time. Mesoscale wind patterns associated with the Great Lakes
should dominate.

Saturday and Sunday...forecast confidence...high

GFS and European model (ecmwf) models are still very similar. There is still a
middle/upper trough over the Great Lakes to Mississippi.

The broad surface high remains near the Great Lakes. Both the
European model (ecmwf) and GFS reduce the amount of light diurnal precipitation
during the afternoon and early evening...with the European model (ecmwf) mainly dry
by Sunday.

Aviation/00z tafs/...

Showers and storms will wind down quickly this evening as daytime
heating is lost.

Will continue to monitor possible MVFR ceilings as main cold pool aloft
pushes through tonight...though model soundings and MOS still
suggest VFR ceilings.

It looks pretty quiet then Monday as high pressure moves into the
area.

Marine...

A Small Craft Advisory remains in effect through the day Monday.
Winds will turn northerly by evening...remaining gust into Monday
morning. Winds will wind down Monday afternoon...with waves
diminishing by evening.

Beaches...

Increasing north winds will bring building waves to the beaches
from Sheboygan south through Kenosha County. Waves will reach 3 to
4 feet along the shoreline by early this evening...building to 4
to 7 feet tonight...then diminishing slowly through the afternoon
into the early evening on Monday. A beach hazards statement is in
effect from this evening through Monday evening.

&&

Mkx watches/warnings/advisories...
WI...beach hazards statement through Monday evening for wiz052-060-
066-071-072.

Lm...Small Craft Advisory until 7 PM CDT Monday for lmz645-646.

Small Craft Advisory until 4 PM CDT Monday for lmz643-644.

&&

$$

Update...mbk

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