Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 192016
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
116 PM PDT Thu Apr 19 2018

.SYNOPSIS...19/1150 AM.

Gusty winds are forecast into early Friday. High pressure and
offshore flow will bring above normal temperatures from Friday into
Monday. An eddy will usher in overnight coastal low clouds and fog
from Saturday into Monday. Then a low should arrive by Tuesday for
increasing onshore flow and a cooling trend through Thursday.

&&

.SHORT TERM (TDY-SUN)...19/115 PM.

The upper low has departed and a ridge will move in tonight and
Friday and remain in place at least through early Sunday for a
warming trend, mainly inland. For today gusty west to northwest
winds that developed behind the departed cold front will continue
into the overnight hours before weakening. Coastal areas, the I5
corridor, and the Antelope Valley will bear the brunt of these
winds with not as much reaching the coastal valleys. Overall a
weaker post-frontal wind event than what we saw Monday but still
at least low end advisory for the above mentioned areas.

Later tonight an eddy circulation is expected to develop that will
help pull in some low clouds into srn LA County. Forecast
soundings indicate just enough of an inversion below 1000` to
support it but probably not a real solid coverage. Some low clouds
also expected to develop along parts of the Central Coast and in
the southern Salinas Valley where there could also be some dense
fog.

With the ridge building in Friday and Saturday expecting temps
inland to jump several degrees, back up into the 80s. Coastal
areas will still have enough of an onshore flow and likely some
marine layer clouds during the morning hours at least to keep
temps quite a bit cooler there.

A little cooling trend expected for Sunday in most areas as the
ridge shifts east and a weak trough moves into the Pac NW. Pretty
decent onshore trend by afternoon so a stronger and earlier sea
breeze expected.

.LONG TERM (MON-THU)...19/116 PM.

Models still in a bit of flux next week with the expected
development of a cutoff low at some point several hundred miles
west of the coast. Today`s GFS solution shifted to yesterday`s
ECMWF, keeping the low west of 130w through at least Thursday then
slowly moving it towards the coast next weekend. Meanwhile, the
ECMWF actually did the opposite and looks a little closer to
yesterday`s GFS. So not a lot of confidence especially around mid
week. Early in the week not expecting a lot of change from Sunday.
Slightly cooler perhaps with the onshore trends but heights stay
fairly high at least through Tuesday so most inland areas should
remain at least a few degrees above normal. After that it just
depends on the speed and magnitude of the upper low and where it
ends up moving inland. Can`t rule out some shower chances when
that happens but right now the models are holding any of that off
until at least Friday. Likely still a lot of back and forth in the
solutions before there is any real confidence beyond early next
week.

&&

.AVIATION...19/1857Z.

At 1655Z at KLAX, there was no marine layer or inversion at KLAX.

The cold front has now exited the region and the clouds will
gradually decrease just as the northwest winds begin to increase
throughout the afternoon. Gusty west to northwest winds will
affect much of the region through this afternoon, with winds
shifting to the north and remaining gusty tonight. There will be
areas of LLWS and moderate UDDF through tonight.

KLAX...Moderate to high confidence in the 18Z TAF. There is a
20-30% chance of low level wind shear through 02Z.

KBUR...Moderate to high confidence in the 18Z TAF. There is a
20-30% chance of low level wind shear through 02Z.

&&

.MARINE...19/1256 PM.

High confidence in at least Small Craft Advisory (SCA) level
winds and possibly seas developing across all coastal waters
today, then continuing thru late tonight before subsiding. There
is a 20-30% chance of Gale force winds late this afternoon and
evening across the outer waters and western portions of the inner
waters and SBA Channel. Steep short-period seas are expected
across the waters thru tonight.

SCA level winds are expected across the outer water Fri afternoon
into Fri night. There is a 30-40% chance of SCA level winds
across the northern inner waters Fri afternoon and evening, and a
20% chance of SCA level winds across the SBA Channel.

There is a 20-30% chance of SCA level winds across the outer
waters Sat through Sun. SCA level winds are likely across the
outer waters and northern inner waters Mon.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 9 PM PDT this evening for zones
      34>36-51. (See LAXNPWLOX).
     Wind Advisory in effect until 3 AM PDT Friday for zones
      39>41-52>54-59-87. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Friday for
      zones 645-650-655-670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (SUN-THU).

No significant hazards expected.

&&

$$

PUBLIC...MW
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...STu

weather.gov/losangeles



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