525
FXUS66 KLOX 312131
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
231 PM PDT Fri May 31 2024

.SYNOPSIS...31/151 PM.

A cooler than normal weather pattern will continue across much of
the area through the weekend as a persistent marine layer remains
in place with strong onshore flow. A warming trend is expected
next week, especially for the interior portions of the area
Wednesday and Thursday as onshore flow weakens.

&&

.SHORT TERM (TDY-MON)...31/206 PM.

Weak troughing along the West Coast has returned, increasing
onshore flow and deepening the marine layer. Sounds like a broken
record but with the possible exception of a few days next week
this may last for quite some time. Onshore flow is about 2mb
stronger than yesterday and models show a slight increase again
tomorrow as well. With the deep marine layer visibilities in most
areas (except the mountain slopes) will be quite good, but
clearing times will be late, and for some coastal areas possibly
not at all. High temperatures for coast and valleys will be 4-8
degrees below normal while most low temperatures will be slightly
above normal thanks to the persistent cloud blanket. Far interior
areas will be 2-5 degrees above normal during the day and
slightly more at night thanks to overnight breezes from the strong
onshore flow that will keep the lower levels well mixed. A few
degrees of warming and slightly earlier marine layer clearing are
likely Sunday and Monday as the trough starts to shift east and
high pressure begins to assert itself over the west. Still below
normal temperatures for coast/valleys but not as much so.

.LONG TERM (TUE-FRI)...31/230 PM.

High pressure will be building over the western states starting
Tuesday and lasting through Wednesday and possibly Thursday before
another trough of low pressure returns for later next week into
next weekend. The warmup will be brief, and mostly confined to
the interior areas, but will likely result in our first 100
degrees readings in quite some time. Based on all the ensemble
runs from the NAEFS and EPS there is a greater than 80% chance of
100 degree or higher temperatures in the Antelope Valley on
Wednesday with lower chances Tuesday and Thursday. Similar chances
for far interior SLO County.

Closer to the coast it`s a much different story. Though warming is
expected for all areas, the amount of warming will be much more
moderate, and for coastal areas high will likely only top out in
the lower 70s at most with some beaches staying cloudy much of the
day. Onshore flow is expected to weaken and be at its lowest point
Tuesday and Wednesday but SST`s are still only around 60 which
will keep temps from warming up too much. Ensembles still indicating
around 60% chance of low 90s in the warmer valley areas like
Woodland Hills Wednesday, but likely in the mid to high 80s
otherwise.

Troughing returns later next week into next weekend for a likely
return of June gloom conditions and well below normal
temperatures for coast and valleys.

&&

.AVIATION...31/1755Z.

At 17Z at KLAX, the marine layer was 2500 ft deep. The top of the
inversion was at 3800 feet with a temperature of 19 deg C.

Moderate to hi confidence in the 18Z TAFs. Low clouds over the
coast and adjacent vlys will clear to near the coast by late this
morning, with MVFR conds likely persisting thru the afternoon at
KOXR, KCMA, KSMO and KLAX. IFR/MVFR cigs will likely spread back
inland tonight and affect all coast and adjacent vly airfields and
continue into late Sat morning. The timing of the dissipation and
onset of low clouds may be off +/- an hour or two, with the
largest uncertainty of the onset of low clouds tonight for KBUR
and KVNY.

For KPRB, KWJF and KPMD, there is hi confidence VFR conds will
continue thru the TAF period. Gusty SW winds will affect the
desert airfields for most of the fcst period.

KLAX...Moderate to hi confidence in the 18Z TAF. MVFR cigs will
likely persist this afternoon with only a 20% chance of the low
clouds scattering out. There is a 50% chance of IFR cigs early
this evening, otherwise MVFR cigs will continue tonight thru Sat
afternoon. No significant east wind expected.

KBUR...Moderate to hi confidence in the 18Z TAF. VFR conds are
expected for the most part into this evening, then IFR cigs should
move in by 07Z. The cigs will improve to MVFR by 11Z and continue
into late Sat morning. The timing of the onset of the low clouds
and changes in flight cats tonight may be off +/- an hour or two.

&&

.MARINE...31/123 PM.

In the northern outer waters zone (PZZ670), winds and seas are
expected to reach Small Craft Advisory (SCA) levels (80% chance)
this afternoon and continue through at least Sunday night.
Elsewhere in the outer waters, winds and seas are expected to
remain below SCA levels thru Saturday morning. SCA level winds
are likely (70% chance) in the central zone (PZZ673) starting
Saturday afternoon then spread to the southern zone (PZZ676)
Saturday night before continuing through at least Sunday night.
SCA conds are likely (70% chance) in all the outer waters Mon and
Monday night before gradually subsiding Tuesday. Conds will
likely be below SCA levels for Wed.

In the inner waters N of Pt. Sal, there is a 30% chance of SCA
level winds Saturday afternoon. SCA conds are likely (60-70%
chance) during the afternoon/eve hours Sat night through Mon.
Conds should then be generally below SCA levels Tuesday and
Wednesday.

In the inner waters S of Pt. Sal, there is a 50%-60% chance of
SCA winds in western portion of the SBA Channel during the
afternoon and evening hours Saturday through Sunday. Otherwise,
conds over the inner waters should be below SCA levels through
Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 2 PM Saturday to 3 AM PDT
      Monday for zone 673. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Sirard
MARINE...Sirard
SYNOPSIS...Hall

weather.gov/losangeles

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