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362
FXUS66 KLOX 231048
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
348 AM PDT Thu May 23 2024

.SYNOPSIS...
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23/248 AM.

Strong onshore flow and a deep marine layer will keep the night
through morning low clouds and fog pattern going with low clouds
reaching the foothills each day. There will be patchy drizzle each
morning. The near shore area will see limited or no clearing through
Saturday. High pressure will bring better clearing and warmer
temperatures to the area starting Sunday and continuing into next
week.
-- End Changed Discussion --

&&

.SHORT TERM (TDY-SAT)...
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23/332 AM.

The marine layer has deepened to 2800 ft and moderate to strong
onshore flow has pushed the low clouds over the csts/vlys and
deep into the mtn passes and foothills. There will be enough lift
near the foothills to produce patchy drizzle. Strong onshore flow
will bring slow clearing to the vlys, slow to no clearing for the
interior coastal sections and no clearing to many if not most
beaches. Max temps will be similar to ydy xcp for the Central
Coast where a little thinning marine layer cloud deck will allow
for some warming. The strong onshore flow will bring advisory
level gusts to the western Antelope Vly foothills and stronger
than normal afternoon winds elsewhere. Max temps will end up 5 to
10 degrees blo normal.

A fairly sharp trof embedded in the broad cyclonic flow will move
over the state on Friday. It will further deepen the marine layer.
Low clouds again will cover all the csts/vlys/foothills and mtn
passes. The trof will bring enough lift to generate areas of
drizzle even away form the foothills. There is even a slight chc
of light rain esp near the foothills. The most likely outcome for
the afternoon will be another day of slow to no clearing there is,
however, a 30 percent chc that the trof along with its attendant
cold air will mix the marine layer out and make it a sunny
afternoon. The trof axis will move over the mtns in the afternoon
and it is vigorous enough to bring a slight chc of a mtn shower.
The strong (~10 mb) W to E push will bring advisory level winds to
the western Antelope Vly and foothills and will likely bring
advisory level winds to many other mtn/interior. Cst/Vly temps
will not change much but the cool air behind the trof will cool
the interior by 4 to 8 locally 10 degrees. Max temps will only be
in the 60s across the csts/vlys and in the 70s for the interior.
These max temps are mostly 10 to 15 degrees blo normal.

Less confidence in the Saturday forecast which currently call for
a continuation of the low cloudiness. There is a chance (40
percent) that the marine inversion will be mixed out and skies
will be much clearer/sunnier than currently fcst. If there are
morning low clouds, offshore trends should make for faster
clearing although some beaches may remain cloudy. Max temps will
warm some but hgts will not have recovered enough to bring
anything more than a couple of degrees.

.LONG TERM (SUN-WED)...23/347 AM.

The GFS and ECMWF and their respective ensemble means continue to
remain in good agreement through Tuesday. On Sunday the
broad west coast trof will finally push to the east and will be
replaced by a weak ridge. Hgts will rise from 577 dam to ~584 dam
on Tuesday. The onshore flow will weaken and the N to S gradient
may even turn briefly offshore.

The night through morning low cloud pattern will continue but the
higher hgts will push the marine layer down and this along with the
weaker onshore push will limit the vly penetration. N to S
offshore flow across the SBA south coast may keep that area clear
through the period. The low clouds will clear earlier and more
completely all three days.

The residual cool air will no longer exist in the interior and
that will allow a 5 to 10 degree warm up across the interior on
Sunday while the csts/vlys will warm 2 to 4 degrees. Then as hgts
continue to rise look for about 2 to 4 degrees of warming each day
Mon and Tue. Max temps on Tuesday will finally come within a few
degrees either side of normals.

While not in the best of agreement the mdls and ensemble favor a
return to upper level troffing and stronger onshore flow. Look for
an increase in marine layer coverage and slow down in clearing as
well as downward trend in temperatures.
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&&

.AVIATION...23/0719Z.

At 0505Z at KLAX, the marine layer was 2800 ft deep. The top of
the inversion was at 5400 feet with a temperature of 16 C.

High confidence in desert TAFs.

Moderate confidence in TAFs. There is a 20 percent chc of brief
SCT conds at any site with no clearing fcst. There is a 30 percent
chc of no IFR cigs at sites with them in the fcst.

KLAX...Moderate confidence in TAF. There is a 20 percent chc of a
few hours of SCT conds in the afternoon. Any east wind component
will be 6kt or less.

KBUR...Moderate confidence in TAF. VFR transition could occur any
time 18Z-21Z.

&&

.MARINE...22/823 PM.

For the Outer Waters, moderate to high confidence in current
forecast. Tonight through Saturday, there is a 70-90% chance of
Small Craft Advisory (SCA) level winds and seas. For Sunday and
Monday, there is a 30-50% chance of SCA level winds.

For the Inner Waters north of Point Sal, moderate confidence in
current forecast. Tonight through Thursday morning, high
confidence in winds and seas remaining below SCA levels. For
Thursday afternoon through Saturday night, there is a 40-50%
chance of SCA level winds, mainly in the afternoon and evening
hours.

For the Inner Waters south of Point Conception, moderate
to high confidence in current. For most of the area, high
confidence in winds and seas remaining below SCA levels through
Monday. However across the western half of the Santa Barbara
Channel, there is a 30-40% chance of SCA level winds through
Thursday then a 60-70% chance on Friday and Saturday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
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CA...Wind Advisory in effect from 2 PM this afternoon to 9 PM PDT
      this evening for zone 381. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for
      zones 670-673-676. (See LAXMWWLOX).
-- End Changed Discussion --

&&

$$

PUBLIC...Rorke
AVIATION...Rorke
MARINE...RAT/Lund
SYNOPSIS...30

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox