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Southwest California area forecast discussion 
National Weather Service Los Angeles/Oxnard California
815 PM PST Sat Nov 28 2015

Synopsis... a weak upper level low will pass to the south
tonight...bringing increasing cloud cover with the slight chance of
of showers over Los Angeles County and adjacent waters. Daytime
highs will slowly rise through the middle of next week as high
pressure builds aloft and weak offshore flow continues.
However...interior areas will remain cold at night through early
next week. A trough of low pressure will then bring a cool down and
a chance of rain for the end of next week.


Short term (tonight-tue) upper low was centered about 200 nm
southwest of Point Conception early this evening. A veil of mostly
high clouds has spread out ahead of this system...covering all of
sba...vtu and Los Angeles counties. All models show this system
weakening and opening up into a positively tilted trough as it
tracks to the south of the coastal waters overnight. However...both
the GFS and the WRF seem to show the system weakening a bit more
quickly than it appears to be doing on it still has a
rather tight little circulation. is probable that
most...if not all... of its precipitation will remain to the S and west
of the forecast area overnight. Will still leave slight chance probability of precipitation
across southern l.A. County...with slightly higher probability of precipitation across the southern
and outer coastal waters. Any showers over land should be on the
light side. Have added a slight chance of thunderstorms to the southern and outer
coastal waters. While models do not show great instability...they
may be underdone as convective cells have developed across the
waters over the past couple of nights. Any slight threat of showers
should be gone by daybreak.

The northern edge of the cloud shield was located right along the
northern borders of sba...vtu and l.A. Counties and it was sagging
very slowly to the south. Expect clear skies across slo County all
night...and across northern sba County most of the night. Therefore...
hard freeze warnings look good for the interior valleys of slo County
and the Cuyama Valley. With the cloud band sagging southward...
expect skies to become clear across the Santa Ynez Valley late freeze conditions are likely there. With cloudiness
expected to linger for much of the night across the Ojai
Valley...have the least confidence in freezing temperatures
there...but a couple of hours of clearing toward daybreak should
allow for temperatures to drop quickly will leave the freeze
warning in place for now.

As the upper trough moves east of the region on Sunday...heights and
thicknesses will rebound. Low level flow will be offshore...and
there may be some locally gusty NE winds through and below passes
and canyons of l.A. And vtu County...but nothing major expected. Maximum
temperatures should edge upward a couple of degrees in most areas on

***From previous discussion***

The air mass will moderate slightly Sunday night/Monday
morning...but still will be some inland areas below freezing.

Otherwise...temperatures will be on the upswing through Tuesday due
to continued offshore flow and building upper level ridge. Warming
trend will be subtle through Monday...then a bit more noticeable on
Tuesday. As for winds...upper support is not do not
anticipate any advisory-level offshore winds through Tuesday.

Long term (wed-sat)...overall...12z models continue to exhibit
decent synoptic agreement through the period. At upper levels ridge
will peak in strength on Wednesday...then a trough will roll across
the West Coast Thursday/Friday...with ridging developing on Saturday.
Near the surface...weak offshore flow Wednesday will shift onshore
Thursday...then transition to a north to northeast flow Friday and

Forecast-wise...main concern will be Thursday/Thursday night as
trough swings across the West Coast. Models move a front across the
area Thursday/Thursday night...which will bring the threat of some
rain to the district. At this looks like the front falls
apart after rounding Point Conception. chances of
measurable rain will occur across slo/sba counties...with lesser
chances across Ventura/Los Angeles counties.

Other than the Thursday/Thursday night time frame...dry conditions
are expected through the extended. With northerly flow developing
behind front on Friday...there could be some pretty gusty north
winds in the usual northerly wind-prone spots.



At 0350z...there was no marine inversion at klax.

An upper low tracking to the south of the region overnight could
bring a period of low VFR ceilings between 4000 and 6000 feet to the
southern half of l.A. County between 08z and 14z...with a slight
chance of brief MVFR ceilings and a shower or two through 14z.
Otherwise...VFR conds are expected across the region through the

Klax...high confidence in 06z taf with VFR conds expected through
the period. There is a 15% chance of light showers and MVFR ceilings
between 08z and 14z.

Kbur...high confidence in 06z taf with VFR conds expected through
the period. There is a 15% chance of light showers and MVFR ceilings
between 08z and 14z.


Marine...28/830 PM

Winds are expected to remain below Small Craft Advisory levels through Monday. Some
locally gusty east to NE winds may affect the inner waters Sun
morning... but winds are expected to remain far below Small Craft Advisory levels.
A large long period northwest swell will begin to move into the waters Sun
night into Monday...and Small Craft Advisory for hazardous seas may be required across
the outer waters Monday afternoon into Tuesday.


Lox watches/warnings/advisories...
freeze warning (see laxnpwlox).
High surf advisory (see laxcfwlox).





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