118
FXUS66 KLOX 052054
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
154 PM PDT Sat Jul 5 2025

.SYNOPSIS...05/1256 PM.

Seasonal temperatures will continue through Monday. Highs will
jump upwards Tuesday, and peak on Wednesday or Thursday. Heat away
from the coast is likely to be hazardous to outdoor workers and
those without air conditioning. Above normal temperatures may last
into early next weekend.

&&

.SHORT TERM (TDY-TUE)...05/124 PM.

Just very minor day to day changes through Monday as a weak low
pressure system meanders off the northern California coast. The
marine layer was quite a bit less extensive this morning as
onshore flow weakened and the marine inversion dropped by around
500 feet. Expecting a similar scenario tonight, then more
extensive low clouds and fog Monday morning as the upper low
wobbles a little to the south causing the marine layer and onshore
flow to increase. But overall very similar conditions through
Monday.

Starting Tuesday the high pressure bubble over Arizona will expand
westward and bring a warmer airmass into the region. Expecting
around a 10 degree jump in high temps away from the coast Tuesday
afternoon, pushing the warmer valleys close to 100 degrees and the
Antelope valley a couple degrees warmer than that. There will
still be enough of an onshore flow that coastal areas within 5
miles of the coast and below 300 feet elevation should mostly
stay in the 60s and 70s but in that intermediate area away from
the coast but not quite into the valleys (such as Downtown LA)
highs Tuesday will be close to 90.

.LONG TERM (WED-SAT)...05/153 PM.

The peak of this heatwave is expected to be Wed and Thu when the
high pressure ridge is at its strongest over So Cal. There is
still a bit of disagreement on how strong the high will be over
the area and deterministic models continue to fluctuate with the
forecast highs next week. The official forecast remains unchanged
today with warmer valleys around 105, deserts 105-108, and
intermediate areas in the 80s to low 90s, with a +/- 5 degree
error window. However, as the event draws closer confidence will
increase and the error window will narrow. There still remains a
potential for heat advisories and/or warnings but that may have to
wait until as late as Monday or Tuesday since the current
forecast temperatures are very marginal for heat risk, especially
for the coastal valleys.

Increasing onshore flow and weakening high pressure should bring
coast and valley temperatures down at least a few degrees Friday
and Saturday, but there may be very little relief for interior
areas like the Antelope Valley and interior SLO/SB Counties. Due
to the potential for an extended period of heat there the chances
for heat advisories or warnings are higher then than other areas.

&&

.AVIATION...05/1752Z.

At 1649Z at KLAX, the marine layer was around 1500 ft deep. The
top of the inversion was 2700 feet with a temperature of 22 C.

High confidence in VFR TAFs for KPRB, KWJF, and KPMD. However,
there is a 10% chance of CIGs arriving at KPRB from 10Z to 15Z
Sun.

Moderate confidence in remaining TAFs. Timing of CIG/VSBY
restrictions may be off by 2 hours and flight minimums by one
category.

KLAX...Moderate confidence in 18Z TAF. CIG/VSBY restrictions may
be off by one category. Arrival and departure of CIGs may be off
by 2 hours. No significant east wind component expected.

KBUR...Moderate confidence in 18Z TAF. Most uncertain in regards
to how long HZ VSBYs will persist, but will likely improve
gradually over the next several hours. There is a 30% chance VFR
conds prevail after 00Z Sun.

&&

.MARINE...05/106 PM.

Small Craft Advisory (SCA) winds will likely continue across the
Outer Waters and the northern Inner Waters much of the time
through the remainder of the 4th of July Weekend. There is a 30%
chance of localized Gale force wind gusts (35 kt) across the far
northern portion of PZZ670 this evening. There are moderate
chances for SCA level winds across the Outer Waters south of Point
Conception early next week, before likely expanding in coverage
to include the entire Outer Waters by Wednesday afternoon.
Significant wave heights are expected to gradually decrease and
will remain well below SCA thresholds from Monday thru Wednesday.

Inside the southern California bight, there is a moderate chance
of SCA level winds each afternoon and evening through mid-week
across western and southern portions 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. Significant wave
heights are expected to remain well below SCA thresholds.

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 Sunday evening for
      zones 87-354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until midnight PDT tonight for
      zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT Sunday for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

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

weather.gov/losangeles

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