969
FXUS66 KLOX 240513
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
913 PM PST Sun Nov 23 2025

.SYNOPSIS...23/723 PM.

Dry conditions are expected through at least Friday with
temperatures rising to near or slightly above normal. Gusty Santa
Ana winds will impact the region at times Tuesday through
Thursday.

&&

.SHORT TERM (TDY-TUE)...23/912 PM.

High pressure aloft in place over the region through the weekend
is breaking down this evening. Stronger westerlies aloft with a
weak shortwave trough will weaken offshore flow, reversing the
flow pattern to weakly onshore across the Southland. A return of
low clouds and fog is occurring, and low clouds should continue
to establish across the coastal sections and lower coastal valleys
tonight and into Monday morning. Low clouds and fog are broken up
initially and difficult to form as a weak marine inversion is in
place this evening. An eddy circulation spinning up in the
southern California bight tonight and into Monday morning should
permit the clouds to regroup for the southern areas. While the
marine layer depth will be deeper south of Point Conception and
likely keep dense fog more patchy in nature, there is higher
concern for areas north of Point Conception where the marine layer
depth is thinner. The latest NAM-BUFR time height sections and
boundary layer relative humidity suggest a little more coverage
over the interior valleys tonight as trapped low-level moisture
will stream into interior San Luis Obispo County out of the
Central Valley. As a result, this will need to watched closely for
dense fog development.

Some cooling will develop across the coastal sections on Monday
as onshore pressure gradients develop. There is some concern that
low clouds and fog could hug the coast into the afternoon as the
eddy circulation and low sun angle could inhibit mixing enough to
keep the marine inversion in place. Thus, the morning low clouds
and fog could hang around a little longer and possibly all day
long.

After the shortwave trough exits the region, an offshore flow
pattern will get underway again on Monday night.

***From Previous Discussion***

The most notable potentially impactful weather in the short term
will be the offshore winds across the region from San Luis Obispo
County south to Los Angeles County beginning Monday night and
continuing into Thanksgiving day, especially the weak to moderate
Santa Ana wind event Tuesday through Thanksgiving morning. The
recent wetting rains have greatly mitigated the wildfire threat in
the area. However, the soils soaked by the rains allows for trees
to more easily be knocked over by winds. Always be cautious
parking under trees, and be sure to secure those outdoor
Thanksgiving decorations.

Moderate northerly winds 20-30 mph will kick things off in LA
County Monday afternoon through the I-5 Corridor and into the
Santa Clarita Valley. While maintaining a healthy LAX-BFL
northerly gradient (5.0-6.0 mb), winds will begin to tilt to the
northeast as the LAX-DAG gradient strengthens to around -6mb by
Wednesday morning. While upper support will be somewhat limited,
the peak surface gradients are enough to warrant a moderate chance
for wind advisories to be issued for late Tuesday into Wednesday
afternoon across Santa Ana Wind prone areas, although winds may
not surface down to the Oxnard plain in this event. In addition to
Santa Ana Wind prone areas being impacted, the northerly winds
look strong enough to pose a low to moderate chances for wind
advisory issuances on the coastal side of the Santa Monica
Mountains from Point Mugu to Santa Monica.

As far as winds go in SLO and Santa Barbara counties, the Santa
Lucia Winds will be strongest across the Santa Lucia Range and
into the interior mountains beginning Monday night and continuing
through the week, peaking Tuesday and Wednesday. Winds in the
25-35 mph range will be common, with isolated gusts to 45 mph.

Temperatures will climb to 5-10 degrees above normal in many
areas Tuesday and Wednesday, with widespread temperatures in the
70s, even in the coastal areas. Warmest valley locations may even
touch the low 80s.

.LONG TERM (WED-SAT)...23/221 PM.

Thanksgiving will begin with Santa Ana winds continuing into the
early afternoon hours, albeit a skosh weaker than Wednesdays
peak, peaking in the 20-30 mph range and tapering off by Turkey
time. Santa Lucia winds will continue across the aforementioned
mountain areas through Friday. As far as high temperatures go,
highs will decrease slightly, but most folks across Southwest
California will experience highs in the 70s and clear skies.

There is quite a bit of uncertainty regarding the forecast for
next weekend as a potential storm system may arrive as early as
Saturday. While there is still considerable disagreement amongst
the GFS and the EC/ECAIFS plus their ensembles, the EC and the
ECAIFS have both trended the upper level trough considerably
further to the southwest, resulting in a majority of their
ensemble members showing at least some precipitation at some point
next weekend. At this point, potential rain totals look quite low
due to low PWATs as the upper level trough meandering across the
Western CONUS before dropping southwest. On the other hand, the
GFS and its ensembles remain much drier, which would certainly
result in a dry Santa Ana pattern.

&&

.AVIATION...24/0024Z.

Around 2325Z, the marine layer depth was around 1400 feet deep at
KLAX. The top of the inversion was near 2200 feet with a
temperature around 16 degrees Celsius.

High confidence in the current forecast through 04Z, then low-to-
moderate confidence thereafter.

VFR conditions are expected through at least 04Z, then there is a
high-to-likely chance of LIFR to IFR conditions at coastal
terminals. After 13Z, there is a moderate-to-high chance of LIFR
to IFR conditions at valley terminals. VFR conditions could
develop as soon as 16Z, or as late as 20Z on Monday.

KLAX...There is a 70 percent chance IFR conditions as soon as
07Z. IFR conditions could delay as late as 11Z, then there is a 70
percent chance of conditions improving to MVFR. VFR conditions
could develop as soon as 16Z, or as late as 20Z, but there is a
30 percent chance of MVFR visibilities lingering longer into
Monday afternoon. An early return of IFR to MVFR conditions should
be expected on Monday evening. Any easterly winds will be less
than 7 knots.

KBUR...There is a 50 percent chance of LIFR to IFR conditions as
soon as 10Z, or as late as 14Z. VFR conditions should develop
around 17Z. No wind impacts are expected at this time.

&&

.MARINE...23/727 PM.

For the Outer Waters, high confidence in current forecast. A
combination of Small Craft Advisory (SCA) level winds and seas
will continue through Monday afternoon. From Monday night through
Thursday, winds and seas should remain below SCA levels. On Friday
there is a 40% chance of NW winds increasing to SCA levels.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Through midnight there is a 30%
chance of SCA level gusts. For Monday through Thursday, high
confidence in winds and seas remaining below SCA levels.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. Through Monday night, high
confidence in winds and seas remaining below SCA levels. For
Tuesday, there is a 30% chance of SCA level northeast winds from
Ventura south to Santa Monica, increasing to a 60% chance Tuesday
night into Wednesday. On Thursday, high confidence in winds and
seas remaining below SCA levels for all of the southern Inner
Waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 3 AM PST Monday for zones
      340-346. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 PM PST Monday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Hall/Lewis
AVIATION...Hall
MARINE...Gomberg/RAT/CMC
SYNOPSIS...Gomberg/Ciliberti

weather.gov/losangeles

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