971
FXUS66 KLOX 312324
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
424 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...31/2323Z.

At 2230Z at KLAX, the marine layer was 1500 ft deep. The top of
the inversion was at 5200 feet with a temperature of 21 deg C.

For the 00Z TAF package, high confidence in deserts TAFs as well
as KPRB. For other TAF sites (coastal and coastal valley),
moderate confidence in TAFs. High confidence in return of CIG and
VSBY restrictions for coastal and coastal valley sites, but low to
moderate confidence in timing of flight category changes.

KLAX...Moderate confidence in 00Z TAF. High confidence in CIG/VSBY
restrictions, but moderate confidence in timing of flight category
changes (could be +/- 2 hours of current forecasts). No significant
easterly wind component is expected.

KBUR...Moderate confidence in 00Z TAF. High confidence in return
of CIG/VSBY restrictions, but moderate confidence in timing of
flight category changes (could be +/- 2 hours of current
forecasts).

&&

.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...RAT
MARINE...Sirard
SYNOPSIS...Hall

weather.gov/losangeles

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