699
FXUS66 KLOX 121800
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1100 AM PDT Sat Jul 12 2025

UPDATED AVIATION SECTION

.SYNOPSIS...12/948 AM.

Night through morning low clouds and patchy fog will affect the
coasts and lower valleys into next week. Max temperatures will
cool today and will end up several degrees below normal. There
will be continued cooling through the middle of next week with
valley highs on Tuesday only in the 80s.

&&

.SHORT TERM (TDY-MON)...12/949 AM.

***UPDATE***

A 5 to 6 mb onshore LAX-DAG gradient and 4 to 5 mb LAX-BFL
onshore gradient paired with the marine layer deepening to around
2400 ft (south of Pt Conception), resulted in clouds surging all
the way to the foothills of the interior mountains and even into
the Santa Clarita Valley. Additionally, some coastal sites
received a trace to 0.01 inches of drizzle thanks to the deepening
marine layer. These clouds will burn off this morning across the
basin, however the constant onshore flow, strengthening again to
around 7 to 9 mb to the east (LAX-DAG), may cause marine layer
clouds to hug the beaches all day today.

While the 500mb heights are slightly increasing compared to
yesterday, the temperatures should be quite similar to yesterday
thanks to the onshore flow in the afternoon (save for the interior
SLO County, where temps will cool a couple more degrees).
Additionally, afternoon and evening onshore winds will once again
affect the Antelope Valley with near advisory level gusts (45
mph), shifting more north to northwest in the evening and
overnight hours, impacting the I-5 Corridor and western portion of
the AV floor and foothills.


***From Previous Discussion***

A small high hgt (~594 dam) upper high will sit atop Srn CA for
the three day short term. warming effects of the warm upper high
will be more than countered by very strong onshore flow to the
east (~9mb in the afternoon) and to the north (~6mb in the
afternoon)

The strong onshore push will bring a night through morning low
cloud pattern to the area for all three days. The high hgts will
keep the marine layer smooshed enough to keep it out of some of
the vlys. The strong capping inversion and coupled with the strong
onshore flow will make for slow clearing and likely no clearing at
many west facing beaches. Low clouds will come roaring back
inland during the early evening hours.

After Friday`s big cool down there will not be much day to day
change in temperatures. Max temps will mostly be in the 70s across
the csts (mid to upper 60s beaches) with 80s and lower 90s in the
vlys. These max temps are mostly 3 to 6 degrees blo normal for the
csts/vlys. The Antelope Vly, free from marine influence, will
continue about 5 degrees above normal.

Lastly the strong north push will bring gusty winds to the
interior, esp the western Antelope Vly 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 (TUE-FRI)...12/1201 AM.

The upper high breaks down on Tuesday and hights fall to to about
591 dam. The strong onshore flow will remain and this will bring
2 to 4 degrees of cooling to almost all of the area. Max temps
will end up 4 to 8 degrees below normal.

The strong onshore flow will continue and may even become a mb
stronger. Conditions on Wed and Thu will be very Temps will not
change much from those readings on Wednesday and Thursday. The
night through morning low clouds and fog will continue unabated
and the beaches will continue to struggle with clearing.

The strong onshore flow will bring gusty (likely advisory level)
winds to some of the mountains as well as the western portions of
the Antelope Valley and foothills. Additionally, the gusty winds
across the mountains and interior along with fairly warm
temperatures and fairly low humidities through Tuesday, will
bring an uptick in fire weather danger.

On Friday both the GFS and EC show a significant increase in
moisture at 700 mb and above advecting in from the SSE. Skies may
turn partly cloudy. Right now there is a 5 to 10 percent chance
for high based thunderstorms.

&&

.AVIATION...12/1759Z.

At 1729Z at KLAX, the marine layer was 2400 ft deep. The top of
the inversion was near 4700 feet with a max temperature of 23 C.

High confidence in VFR TAFs for KWJF and KPMD.

Moderate confidence in remaining TAFs. Lower confidence in time of
clearing today for coastal sites south of Point Concpetion (+/- 2
hours). There is a 30% chance of no clearing at site with VFR
conds fcst, and a 30% chance for clearing for sites with low
clouds through the period. Return of cigs tonight may also be off
+/- 2 hours, but high confidence in low clouds returning, except
for KPRB, where there is a 30% chance for LIFR to IFR conds from
10Z to 17Z.

KLAX...Moderate confidence in TAF. There is a 30% chance for OVC-
BKN conds to continue through the period. Otherwise, clearing and
arrival times for cigs may be off by +/- 2 hours. Minimum cig
height may be off +/- 300 feet. No significant east wind component
expected.

KBUR...Moderate confidence in TAF. Arrival of cigs may be off +/-
2 hours. Minim cig height may be off +/- 200 feet.

&&

.MARINE...12/919 AM.

Localized Small Craft Advisory (SCA) NW winds (21 kts) near Point
Concpetion south to the western Channel Islands and WNW winds in
southern Inner Waters from nearshore Point Mugu to Pacific
Palisades and into the San Pedro Channel are possible Sunday
afternoon and evening. Otherwise, relatively benign conditions
will continue through at least the middle of next week.

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...Lewis
SYNOPSIS...30

weather.gov/losangeles

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