063
FXUS66 KLOX 021749
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1049 AM PDT Thu Oct 2 2025

.SYNOPSIS...02/928 AM.

A series of weak disturbances will keep a persistent night
through morning low clouds pattern going across most of the coasts
and some lower valleys through Friday. Weak offshore flow will
bring mostly sunny skies to the area for the weekend. Gusty winds
are expected Friday and Friday night for some mountain and desert
locations.

&&

.SHORT TERM (TDY-SAT)...02/927 AM.

***UPDATE***

Have increased the cloud coverage for today and tomorrow and
introduced a slight chance (~15%) of rain showers in the northern
portion of the CWA for today as the trough looks like it will
affect us a little more than previously thought.

***From Previous Discussion***

Overall, 00Z models in good synoptic agreement through the short
term period. At upper levels, a low will move across northern CA
today and Friday then into the Great Basin on Saturday. Near the
surface, onshore flow will peak today then gradually weaken on
Friday with very weak offshore flow developing on Saturday.

Forecast-wise, no significant issues are expected through the
period. As the upper low makes it track across northern CA and
into Nevada, it may bring some mid/high level clouds to areas
north of Point Conception today/Friday, but best chances of any
measurable rain look to remain north of the forecast area as best
frontal dynamics are well north of the area. Otherwise, will
anticipate rather widespread stratus/fog this morning with decent
onshore gradients, but current satellite trends would indicate
much less coverage this morning. So, an update may be needed
towards the end of the shift if stratus decides to be limited. For
tonight/Friday morning, stratus coverage should be much more
limited with no stratus expected Saturday morning (due to the weak
offshore flow).

As for winds, will expect an increase in northwesterly winds
behind the cold frontal passage (associated with the upper low)
this evening through Friday night as northerly offshore gradients
strengthen. For this evening/overnight, high resolution ensembles
indicate a 20-30% chance of low-end advisory level winds across
the western Santa Ynez Range. For Friday evening and night, the
chances for advisory level northwesterly winds increase to 60-80%
for the western Santa Ynez Range and to the 30-50% chance range
across the eastern Santa Ynez Range as well as the I-5 Corridor
and northwest portions of the Antelope Valley. For Saturday,
there will be some weak northeasterly winds, but speeds are
expected to remain below advisory levels.

As for temperatures, will expect a cooling trend for all areas
today and Friday with the passage of the upper low to the north.
On Saturday, temperatures will rebound with higher H5 heights and
thicknesses as well as weak offshore flow in the morning.

.LONG TERM (SUN-WED)...02/206 AM.

For the extended, 00Z models continue to exhibit decent synoptic
agreement. At upper levels, trough will remain over Central CA
Sunday and Monday then will lift out of the area. Near the
surface, onshore flow increases on Sunday/Monday, but weakens on
Tuesday/Wednesday.

Forecast-wise, no significant issues are expected through the
period. Marine layer stratus/fog should increase in coverage
Sunday/Monday with increasing onshore gradients and lowering H5
heights. However for Tuesday/Wednesday, the stratus coverage
should diminish as H5 heights rising and offshore trends in the
surface gradients. Other than any stratus, skies should remain
mostly clear through the period.

As for temperatures, a gradual cooling trend can be expected for
Sunday and Monday with increasing onshore flow and lowering H5
heights. However, those temperatures will rebound on Tuesday and
Wednesday as H5 heights rise and onshore surface gradients relax.

A bit further out into the Thursday/Friday time frame, there is
the possibility of some subtropical moisture moving into the area
as models indicate another tropical storm off the Baja Mexico
coast. Confidence in any details remains very low at this time as
models handle this feature dramatically differently. However, it
is something to watch for the second half of next week.

&&

.AVIATION...02/1743Z.

At 1650Z at KLAX, the marine layer was 1800 ft deep. The top of
the inversion was at 2700 ft with a temperature of 17 C.

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

Moderate confidence in remaining 18Z TAFs. Timing of CIG/VSBY
restrictions may be off +/- 3 hours, while flight categories may
be off by one or two.

KLAX...Moderate confidence in 18Z TAF. Flight cat changes may be
off by +/- 3 hours. 25% chance of IFR CIGs OVC008 through 12Z
Friday once clouds arrive. No significant east wind component
expected through the forecast period.

KBUR...Moderate confidence in 18Z TAF. Flight cat changes may be
off by +/- 2 hours. 30% chance that CIGs arrive as MVFR >0VC010.

&&

.MARINE...02/743 AM.

UPDATE: Issued a Small Craft Advisory (SCA) to begin now instead
of later tonight for zone PZZ670/673 as seas have climbed above
10 feet.

High confidence in NW winds increasing to Small Craft Advisory
(SCA) levels this afternoon across the Santa Barbara Channel and
late tonight across the Outer Waters and nearshore waters along
the Central Coast. Moderate confidence in Gale Force of 34-40
knots winds around Point Conception and south to San Nicolas
Island as well as across the entirety of the Santa Barbara
Channel Friday afternoon into the late night hours. Winds will
flirt with Gale Force levels from the immediate Central Coast out
to 40 NM offshore during the same time period. Confidence is high
that winds will diminish some, but SCA level winds will be common
through Saturday night, especially in the afternoon and evening
hours. Then conditions look to remain below SCA levels Sunday and
into next week.

For the waters adjacent to Los Angeles and Orange counties,
moderate confidence in widespread SCA level NW winds Friday
afternoon through evening, including nearshore. There is a low
chance for brief Gale Force winds near Anacapa Island during this
period. Then conditions look to remain below SCA levels over the
weekend and into next week.

Seas will be large and very choppy, with seas peaking between 8
and 12 feet for the Outer Waters and nearshore Central Coast
waters, and 5 to 8 feet for the inner waters south of Point
Conception, highest in the Santa Barbara Channel.

Consider adjusting any plans or remaining in safe harbor on
Friday when conditions are forecast to be the worst.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect from 9 PM this evening to 3 AM
      PDT Saturday for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to
      noon PDT Friday for zone 650. (See LAXMWWLOX).
     Gale Watch in effect from Friday afternoon through late
      Friday night for zones 650-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect until noon PDT Friday for zone
      673. (See LAXMWWLOX).
     Small Craft Advisory in effect from 9 PM this evening to noon
      PDT Friday for zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson/jld
AVIATION...Black
MARINE...Lewis/Black
SYNOPSIS...jld

weather.gov/losangeles

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