Charter Oak California Weather Forecast Discussion

704
FXUS66 KLOX 071135
AFDLOX
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
435 AM PDT Tue Oct 7 2025
.SYNOPSIS...07/1229 AM.
Slightly cooler than normal conditions will continue through
midweek due to an upper level low pressure over the West. Night
through morning low clouds and fog will continue through the week.
There is a slight chance of rain for late in the week for Los
Angeles County.
&&
.SHORT TERM (TDY-THU)...07/305 AM.
After an early evening surge the marine layer has retreated and is
now struggling to penetrate into LA county. This is not the case
for SLO/SBA/VTA counties where marine layer clouds cover all of
the csts/vlys. By dawn, however, the low clouds should move in and
cover the LA csts/vlys. An easterly wind surge develops at 850 mb
and this will ensure that clearing is complete. The upper level
easterly winds will also bring 1 to 2 degrees of warming to most
areas save for the Central Coast where it will be too weak to
prevent a stronger cooling sea breeze.
Look for a fairly similar marine layer pattern on Wednesday with
just a little less vly coverage. The big news is the pattern shift
with strong SW flow setting up over Srn CA in response to the
southward progression of a anomalously large upper low west of
the WA cst. At the same time Hurricane Priscilla will begin her
northward trek just off the Baja cst. This pattern shift will not
affect the days weather much which will feature mostly sunny
skies save for the morning marine layer stratus and cooler temps
due lowering hgts and stronger onshore.
It looks like Priscilla will not be near enough to the area on
Thursday to affect the weather. The weather then will be
dominated by the SW flow around the south end of the upper low.
Offshore flow is forecast to develop from the north and this will
limit the amount of low clouds south of Pt Conceptions. Max temps
will continue to run 2 to 4 degrees blo normal.
.LONG TERM (FRI-MON)...07/1228 AM.
There is, perhaps, a little less uncertainty with the Fri/Sat
forecast as more ensembles are now favoring a scenario where the
strong SW flow assoc with the large upper low picks up and sweeps
the moisture from Priscilla to the east. There are still some
ensemble members that show rain for LA county so a 15 to 20
percent chc of rain remains in the forecast. The trof should start
to disrupt the marine layer and there will be less and less
morning low clouds. Weaker onshore (or even weak offshore) sfc
pressure gradients will being warming to most areas Friday. Cool
air advection from the trof passing overhead Saturday will cool
the csts/vlys 2 to 4 degrees and the interior 4 to 8 degrees.
Long wave troffing sets up over the area on Sunday. There should
be no morning low clouds as the cool air and mixing from
Saturday`s trof passage will likely destroy the marine inversion.
IN addition there will be some offshore flow with some gusty
northerly winds. Mostly sunny skies, the lack of cool air
advection and the offshore flow will allow for several degrees of
warming. Even with the warming most max temps will end up 3 to 5
degrees below normal.
Another trof will rotate out of the interior on Monday with
another shot of cold air advection. There is the potential for
some very gusty northerly winds in the wake of this trof later in
the day. Cool air from the trof passage will lower max temps
another 2 to 3 degrees. With almost all cst/vly locations expected
to see max temps in the 70s.
&&
.AVIATION...07/1134Z.
At 1050Z at KLAX, the marine layer was 1400 feet deep. The top of
the inversion was near 3600 feet with a temperature of 22 C.
High confidence in TAFs for KPRB, KPMD and KWJF.
Moderate confidence in remaining TAFs. VFR transitions could be
off by +/- 90 minutes. Return of low clouds this evening could be
off by +/- 2 hours.
KLAX...Moderate confidence in TAF. VFR transition could be as
early as 18Z. Low clouds could arrive as early as 02Z. No
significant east wind component expected.
KBUR...Moderate confidence in TAF. VFR conds could arrive as late
18Z. Low clouds could arrive any time between 09Z-13Z tonight.
&&
.MARINE...07/425 AM.
Across the outer waters and nearshore along the Central Coast
conditions are likely to remain below Small Craft Advisory (SCA)
criteria through Thursday, with increasing winds to near or above
SCA levels possible by Friday, generally south of Point Conception.
SCA winds are likely (50-60%) for the weekend, with a 30% chance
for gale force winds Saturday.
For the inner waters south of Point Conception, conditions should
generally remain below SCA criteria through mid week. Isolated
gusts approaching SCA levels are possible this evening and
Wednesday evening near Point Dume and the San Pedro Channel. There
will then be a 30-40% chance for SCA level winds Friday, with the
best chances in the Santa Barbara Channel. There is a 60% chance
for SCA winds for Saturday evening.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...Rorke
AVIATION...Rorke
MARINE...Phillips/Ciliberti
SYNOPSIS...MW
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion