157
FXUS66 KLOX 131745
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1045 AM PDT Sun Jul 13 2025

UPDATED AVIATION DISCUSSION

.SYNOPSIS...13/158 AM.

Night through morning low clouds and patchy fog will affect the
coasts and most valleys into next week. Max temperatures will
warm slightly today and Monday but remain below normal except for
far interior valleys. A cooling trend will develop Tuesday and
continue through the middle of next week when valley highs are
only expected to be in the 80s.

&&

.SHORT TERM (TDY-TUE)...13/940 AM.

***UPDATE***

A 1900 ft marine layer depth at KLAX paired with onshore
gradients around 5 mb to the east and 3 mb to the north, has
allowed marine layer clouds to push into the valleys once again
overnight. However, the inversion above the marine layer is a tad
bit stronger than yesterday, and a little bit more widespread
drizzle was apparent this morning, as weather stations up and down
the coast in the region reported a trace to 0.01 inches of rain
(drizzle) this morning.

Thanks to the positioning of the high overhead slightly shifting
and more northerly (and warmer) flow affecting the interior
areas, the marine layer layer clouds will be a bit quicker to burn
off this morning away from the coasts. At the coasts, however,
persistent onshore flow will lead to slow, if any, clearing at the
beaches. As a result of the northerly interior flow, temperatures
across the interior will warm a few degrees, bringing temps back
into the 100 to 105 range (some stations fell just short of 100
degrees yesterday). As for the areas away from the coast, the
earlier burn off time for clouds will help add for another few
degrees of warming, bringing temps into the 80s to low 90s.
Meanwhile, closer to the coasts/beaches will be in the high 60s to
high 70s range, save for the Central Coast beaches, where 50s to
60s will remain possible.

Gusty, sub-advisory, SW winds will continue across interior areas
such as the western Antelope Valley and foothills this afternoon
and evening. Then an earlier return of marine layer clouds to
coastal areas is expected this evening.

Forecast looks in shape, and no updates were needed in the morning
update package.

***From Previous Discussion***

A small upper high over Srn CA will slowly break down today
through Tuesday. Hgts today will be an impressive 596 dam and will
slowly fall to 591 dam by Tuesday. The effects of these higher
than normal hights will be greatly mitigated by the strong onshore
push both to the east (5 to 9 mb) and north (4 to 6 mb).

There will be minimal day to day changes with the cloud cover
where skies will be clear with the major exception of a night
through morning low cloud pattern that will cover the csts and
vlys. The strong onshore flow will make for slower than normal
clearing and no clearing at many west facing beaches. The low
clouds will also arrive earlier in the evening for the coastal
areas.

Max temperatures today and Monday will mostly be in the 70s
across the coasts (mid to upper 60s beaches), with 80s and lower
90s in the valleys. These max temps are mostly 3 to 6 degrees
below normal for this time of year. The Antelope Valley, however,
with no marine influence will continue to see max temps from 100
to 105 each day which is 5 degrees above normal. The lower hgts on
Tuesday will bring max temps down by 2 to 4 degrees at the csts
and 3 to 6 degrees elsewhere.

Lastly the strong push to east will bring gusty winds to the
interior each afternoon and evening, especially the western
Antelope Valley and foothills. Wind speeds will be close to
advisory levels but likely just under with a few of the typical
gusty locations seeing gusts to 45 mph.

.LONG TERM (WED-SAT)...13/304 AM.

For the long term period the upper pattern will become very weak
with no synoptic scale features to speak of. Hgts will be near 590
dam through the period. At the sfc the strong onshore flow will
continue through Thursday, and may even become a mb stronger,
before starting to weaken thursday night through Friday.

The condtions for Wednesday and Thursday will be very similar to
Tuesday. The night through morning low clouds and fog will
continue unabated and the beaches will continue to struggle with
clearing. Max temps will continue to run 3 to 6 locally 8 degrees
below normal with highs only in the 80s across the vlys. Strong
onshore flow will continue to bring gusty (likely advisory level)
winds to some of the mountains as well as the western portions of
the Antelope Valley and foothills.

Both the GFS and EC agree that starting Thursday evening and
really ramping up Friday there will be a significant amount of
moisture advecting in from the SSE at 700 mb and above. Yesterday
both the GFS and EC were dry below 700 mb, but the 00Z run of the
EC now shows significant moisture down to 850 mb. The NBM has
little in the way of cloud cover fcst but would not be surprised
is skies were at least partly cloudy. As of now, there is a 10
percent chance for monsoonal thunderstorms during the afternoon
and evening hours Thursday through Sunday.

&&

.AVIATION...13/1744Z.

At 1714Z at KLAX, the marine layer was 1800 ft deep. The top of
the inversion was at 4500 feet with a max temperature of 24 C.

High confidence in VFR conditions for KWJF and KPMD.

Moderate confidence in remaining TAFs. VFR transition may be off
by +/- 90 minutes with a 30 percent chc of no clearing at coastal
sites south of Point Concpetion excluding KCMA and KLGB. Arrival
of cigs tonight may be off +/- 2 hours.There is a 20% chc for cigs
002-004 at KPRB between 12Z and 16Z.

There is a 30 percent chc of 1/4SM FG conds 12Z-15Z at KSBP,
KSMX, and KSBA. 20% chance for KOXR and KCMA.

KLAX...Moderate confidence in TAF. VFR conds could arrive any time
19Z thru 22Z with a 30 percent chc of no clearing. Arrival of cigs
tonight may be off +/- 90 minutes. Minimum cig hgt may be off +/-
200 ft. Any east wind component will be 6 kt or less.

KBUR...Moderate confidence in TAF. Arrival of cigs tonight may be
off +/- 2 hours. There a 20 percent chc of cigs remaining 005 or
higher.

&&

.MARINE...13/825 AM.

This afternoon and evening, localized Small Craft Advisory (SCA)
W to NW winds may impact the waters around Point Conception south
to the Channel Islands, and nearshore from Point Mugu to Pacific
Palisades and through the San Pedro Channel. Expecting similar
winds of a lower magnitude for the same areas Monday evening.
Otherwise, relatively benign conditions will continue through
Wednesday. More widespread SCA level winds are possible Friday,
focused on the outer waters. Night to morning patchy dense fog is
possible through at least Monday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Rorke/Lund
AVIATION...Lewis
MARINE...Phillips/Lewis
SYNOPSIS...Black

weather.gov/losangeles

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