Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 301142

442 AM PDT Sun Apr 30 2017

...Aviation discussion updated...


It will be sunny and warm today. A weak marine layer will develop
on Monday and will bring some cooling to the coastal areas. Mostly
clear skies and slightly above normal temperatures will continue
for the upcoming week.



High pressure and weak offshore flow have brought clear skies to
the area. There will be some weak morning canyon winds but nothing
of note. The coasts will cool some due to the early seabreeze and
the vlys likely be at least as warm as ydy or maybe a little
warmer due to a warmer airmass. The interior will for sure be a

A weak eddy will bring some morning marine layer clouds to the LA
coast but otherwise Monday will be a sunny day. The weak offshore
flow will turn onshore and this knock 3 to 6 degrees off of the
coastal temps and 2 to 4 degrees from the vly temps. The upper
level ridge actually strengthens a touch and the interior will see
further warming.

The NAM forecasts a weak burst of north winds on Tuesday morning
so there may be a few canyon breezes in the morning. No where near
strong enough to push the stratus away from the srn LA county
coast so the LGB-LAX area will likely have low clouds in the
morning. Coastal and Vly temps are forecast to be similar to
Monday although if the north winds are just a little stronger
there will be some warming in the vlys. Temperature guidance
suggests further interior warming but the ridging patter is
unchanged from Monday and really think temps will be quite
similar to Monday`s values.


00Z EC and GFS have come into agreement for the long term forecast
with the GFS trending to the more interesting cooler wetter EC.

The ridge will persist over the state Wednesday and really do not
see much change in the weather from Tuesday.

The ridge will push eastward on Thursday and by afternoon the
state will be on the back side of it. But all in all it should
have too much of an effect on the weather. There will be some
morning marine layer clouds in the LAX-LGB area but otherwise it
will be a sunny day. Max temps in the interior will be 5 to 10
degrees above normal while the coastal areas will see highs at or
a few degrees above normal.

An upper low begins to work its way down the west coast on Friday.
Hgts will lower and the upper level flow will take on a cyclonic
bent. The marine layer clouds will expand and max temps across the
vlys and the interiors will cool.

The upper low elongates and moves further south on Saturday. This
will create a large marine layer that will cover the coasts and
vlys. Max temps will drop to below normal for the first time in
more than a week

The upper low expands and moves into the area Saturday night and
Sunday. If this comes true there will be scattered shower activity
across the area. But this solution is still along ways away and
could well change with time.



At 09z at KLAX... There was a surface based inversion. The top
was around 1200 feet with a temperature of about 22 degrees

Overall... High confidence in the current TAFs. There is a less
than ten percent chance of MVFR conditions developing along the
Los Angeles County coastal sites through 16z and a fifteen
percent chance of IFR/MVFR conditions developing Monday morning.
Otherwise and elsewhere VFR conditions will prevail.

KLAX... High confidence in the current TAF. There is a less than
ten percent chance of MVFR conditions developing through 16z
and a fifteen percent chance of IFR/MVFR conditions developing
Monday morning. Otherwise VFR conditions will prevail. Any east
winds will be 7 knots or less.

KBUR... High confidence in the current TAF. VFR conditions will


.MARINE...30/230 AM.

Small Craft Advisory (SCA) level conditions will persist across
the Outer Waters through at least Tuesday.  The winds may drop
below SCA conditions in the morning but will strengthen again in
the afternoon and evening hours.  Winds over the Santa Barbara
Channel and Santa Monica Basin will approach SCA conditions at
times during this period as well.

Due to the gusty winds...choppy seas should be expected in most
areas (including near shore) into next week.


PZ...Small Craft Advisory in effect until 9 AM PDT Tuesday for
      zones 670-673-676. (See LAXMWWLOX).


No significant hazards expected.



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