963
FXUS66 KLOX 041735
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1035 AM PDT Fri Jul 4 2025

.SYNOPSIS...04/939 AM.

Temperatures will be near normal for July through at least this
weekend, with overnight to morning low clouds and fog continuing
for the coasts and valleys. Tuesday through much of next week an
extended period of well above normal temperatures is expected.

&&

.SHORT TERM (TDY-SUN)...04/946 AM.

***UPDATE***

The marine layer remains around 2000 feet deep across the LA
Basin sloping down to around 1200 feet along the Central Coast.
With this in mind along with minimal changes to pressure
gradients, temperatures today are expected to be within a few
degrees either way of yesterday.

However, models are indicating about a 50% reduction in the marine
layer depth tonight and Saturday along with a 3mb decrease in
onshore flow to the east and north which should bump highs at
least 5 degrees in most areas with less morning clouds in the
valleys and earlier clearing elsewhere.

***From Previous Discussion***

Temperatures today will be a few degrees below normal, with
highs in the 70s for the coasts, 80s for most valleys, and mid
90s across the deserts. Weak troughing will maintain similar
temperatures this weekend, except for a couple degrees of warming
for the LA Basin. Overnight to morning marine layer clouds and
fog will continue for the coasts and valleys each day, even
lingering into the day at some beach locations. Smoke from the
Madre Fire in southeastern San Luis Obispo County may impact the
region, but will likely be fairly elevated for most areas. In
terms of winds, typical onshore west to southwesterly winds will
occur each afternoon and evening across interior areas including
the Antelope Valley, and northwest Sundowner winds will occur
each evening across southwestern Santa Barbara County.

.LONG TERM (MON-THU)...04/257 AM.

Weak troughing will continue for the region Monday and keep
conditions similar to the weekend, with temperatures generally
near or several degrees below normal. Tuesday through at least
Thursday a high pressure system will build centered over Arizona.
This will send 500 mb heights soaring over Southern California
with heights around 597 dam likely over Los Angeles County.
Temperatures will be notably warmer on Tuesday, with heat peaking
on Wednesday or Thursday for most areas. Temperatures will easily
surpass 100 degrees across the deserts and interior valleys and
mountains. Highs in the mid 80s to mid 90s will be common across
the coastal plains including DTLA, and even some coastal areas may
see temperatures well into the 80s, especially on Thursday.
Heat Advisories are likely to be issued for most valleys for mid
next week, though well above normal conditions may linger through
the next weekend. Additionally, if the forecast continues to trend
warmer, there is a chance that Extreme Heat Watches/Warnings will
be needed for many valley, desert, and mountain areas. Residents,
particular outdoor workers and those without air conditioning,
are advised to prepare for an extended period of above normal
temperatures.

Southeasterly flow aloft may bring some monsoonal mositure to the
region, with PWATs of an inch or more possible, especially for LA
County. This mositure combined with high surface heating will
offer a small chance for monsoonal thunderstorms each afternoon
Tuesday through Thursday. Thunderstorm chances will be focused
over the Antelope Valley and the San Gabriel Mountains, with
slimmer chances for the Ventura County Mountains and far eastern
Santa Barbara and San Luis Obispo Counties. Hazards with any
storm may include dry lightning fire starts, gusty winds, and
brief heavy downpour.

&&

.AVIATION...04/1734Z.

At 1657Z at KLAX, the marine layer was 1900 ft deep. The top of
the inversion was around 4800 feet with a temperature of 20 C.

High confidence in VFR TAFs for desert airfields (KWJF and KPMD).

Moderate confidence in flight categories, and low confidence in
timing for remaining TAFs expect for KBUR, KVNY, and KPRB.
Also, there is a 20% chance CIGs do not arrive at KSBP.

KLAX...Moderate confidence in 18Z TAF. Arrival and departure times
of CIGs may be off by 2 hours. There is a >30% chance cigs remain
above 010 (MVFR). There is a 20% chance for CIGs to linger from
17Z Sat - 00Z Sun. No significant east wind component expected.

KBUR...High confidence in 18Z TAF. There is less than a 10% chance
CIGs (~010) arrive. Otherwise, VFR conditions are expected.

&&

.MARINE...04/752 AM.

Small Craft Advisory (SCA) winds are likely across the Outer
Waters and norther Inner Waters much of the time through the 4th
of July Weekend. Local Gale Force wind gusts are possible at times
through Sunday, with the best chances in the northern Outer/Inner
Water this afternoon into the evening hours (PZZ645/670).
Wave heights will peak around 8 to 10 feet through the weekend.

Inside the southern California bight, there is a moderate chance
of SCA level winds each afternoon and evening Friday through the
weekend across the western portion of the Santa Barbara Channel.
Local gusts up to 21 kts may occur near Point Dume, and into the
San Pedro Channel during the aforementioned time.

Patchy dense fog may affect the coastal waters, especially north
of Point Conception overnight and in the morning hours through
this weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Saturday evening
      for zones 87-354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 6 PM PDT this evening
      for zones 645-670. (See LAXMWWLOX).
     Gale Warning in effect from 6 PM this evening to 3 AM PDT
      Saturday for zones 645-670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 6 PM this evening to 3 AM
      PDT Saturday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Schoenfeld
AVIATION...Black
MARINE...Lewis/Black
SYNOPSIS...Schoenfeld

weather.gov/losangeles

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