911
FXUS66 KLOX 110431
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
826 PM PST Fri Jan 10 2025

.SYNOPSIS...10/729 PM.

Another round of gusty north to northeast winds will develop
later Saturday into Sunday, then a stronger offshore wind event is
possible between Monday night and Wednesday. Otherwise, dry
weather is expected at least through the middle of next week with
cold overnight temperatures in wind protected areas.

&&

.SHORT TERM (FRI-MON)...10/757 PM.

The gusty Santa Ana winds that occurred earlier this morning
weakened this afternoon, with an onshore wind shift across many
coastal and coastal valley locations. As a result, the current
Red Flag Warning was cancelled earlier today. For tonight,
an upper level trough will dig into the Great Basin, with winds
shifting to the northwest and north across the typical
NW-N wind corridors, such as the I-5 corridor, Santa Ynez Range,
San Gabriel Mountains (north of the Eaton Fire), and Santa Monica
mountains. These areas will see gusts in the 25 to 40 mph range
tonight with continued low humidities, resulting in elevated
to brief critical fire weather conditions in these areas.

By Saturday morning, surface high pressure will build
across the Great Basin, associated with increased cold
air advection. This will increase the northeast winds
on Saturday across the wind prone mountains and valleys
of LA/Ventura counties. Northeast wind gusts will mostly
be in the 20 to 35 mph range for most of the wind prone
areas of LA/Ventura counties (including Malibu/Palisades area),
except gusts of 35 to 50 mph across the San Gabriel mountains
(north of the Eaton Fire) and Santa Susana mountains, where wind
advisories will be issued for Saturday, leading up to the High
Wind Watch which begins at 6 pm Saturday. These gusty Santa Ana
winds on Saturday will lead to elevated to brief critical
fire weather conditions.

*** From previous discussion ***

Models have been consistent with this pattern and confidence is
high that gusty winds will return to most of the same areas
Saturday night into Sunday, strongest in the LA, Santa Susana, and
western Santa Monica mountains where high wind watches have been
posted through Sunday afternoon. Will likely need wind advisories
across at least some of the LA/Ventura valleys and coastal areas
by Sunday morning.

Gradients and especially upper level support drop off Sunday
afternoon and evening so there is high confidence that winds will
decrease to below 30 mph in most areas. Models do show a very
slight increase winds winds aloft and offshore flow again Monday
morning which could pose some issues for local brush fires but not
enough for wind advisories.

The previously mentioned cold air advection for Saturday night
into Sunday will lead to some very cold temperatures in areas that
are protected from the Santa Ana winds, which is most of the area
except for the coast and valleys of LA/Ventura County. So expect a
significant drop in overnight temperatures Saturday night into
Sunday, with possibly some sub 20 degree lows in the Antelope
Valley and perhaps across portions of interior SLO County.
Although there have already been several sub-freezing mornings in
those areas, some freeze hazards may be prudent if confidence
grown in lows below 20.

.LONG TERM (TUE-FRI)...10/231 PM.

Ensembles continue to show a stronger offshore flow developing
Tuesday into Wednesday with more of an easterly orientation. This
has the potential for being as strong or stronger than all but the
initial Santa Ana event last Tuesday as this will not likely have
any mountain wave activity. Based on the latest ensembles wind
speeds across LA/Ventura Counties look to be in the 40-60 mph
range with isolated 80 mph gusts in the LA county mountains.

Gradients and upper support start to weaken later Wednesday into
Thursday leading to a significant decrease in wind speeds and an
eventual shift to onshore by Friday.

Some of the ensemble runs have been indicating a chance for some
rain later in the week. Many of the solutions show some energy
pinching off the primary upper low and moving west to as far as
600 miles off the southern California Coast. Given the source
region the low doesn`t have a lot of moisture with it. However,
there are some solutions that show the upper low entraining some
deeper moisture from the south and moving into the area later
Thursday into Friday. Confidence is still very low, but there is
at least a chance of rain across mainly southern areas later this
week. Likely on the lighter side, with a non-zero chance of
isolated heavier showers.

&&

.AVIATION...10/2349Z.

At 2350Z at KLAX, there was no marine layer nor an inversion.
There is a moderate chance at times of MVFR smoke conds at Los
Angeles County coastal and valley terminals. Otherwise, expect
VFR conds to dominate the fcst pd.
KLAX...There is a 40% percent chance of MVFR smoke conds. There
is a 30% chance of a east wind component of 6-8 kt from 10Z to
18Z.

KBUR...There is a 50-60% chance of MVFR smoke conds at times
during period.

&&

.MARINE...10/727 PM.

Across the waters beyond 20 NM from the Central Coast and south
to near Point Conception to San Nicolas Island, there is a 70-80
percent chance of SCA winds developing between tonight and early
Saturday morning especially in PZZ670.

There is a high chance (80-90%) for a combination of widespread
SCA level winds/seas across much of the outer waters excluding
eastern portions of PZZ676 (seas will likely stay below SCA
criteria) on Saturday.

Winds and seas will diminish Sunday afternoon and generally
remain at or below SCA levels through at least Wednesday. Best
chances for SCA level wind/seas during the aforementioned
timeframe appears to be the Western portions of PZZ670, and
eastern portions of PZZ676 due to offshore winds.

Across the southern California bight, gusty SCA level NE winds
will develop again Saturday night into Sunday nearshore. The
strongest winds would be expected between Ventura harbor and
Pacific Palisades. There is a 40% chance of GALE force gusts
nearshore, especially around daybreak Sunday. There is a moderate
chance (50-60%) of 20 to 30 kt winds through the San Pedro
Channel and at Avalon Harbor.

Winds and seas may diminish between Sunday night into early
Monday for a brief period, but then SCA conds are very likely
nearshore Monday night through Wednesday. A high chance of
offshore (northeast) GALE force winds during this period.

For the nearshore waters along the Central Coast, winds and seas
are expected to remain borderline or below SCA levels through at
least Saturday night. There is a 30 percent chance of SCA level
winds nearshore between Saturday night and Sunday morning, and
again between Tuesday morning and Wednesday morning.

&&

.FIRE WEATHER...10/825 PM.

Winds will shift to the northwest tonight, with gusts of 25 to 40 mph
over the wind prone areas, including southwest Santa Barbara County
where a few hours of critical conditions are possible. The winds shift
back to northeast on Saturday and will strengthen Saturday Night into
Sunday when gusts of 35 to 50 mph will be common over Los Angeles and
Ventura Counties. Local gusts of 50 to 70 mph are possible in some
mountains. With continued dry conditions, Red Flag Warnings are likely.
While a brief reprieve from the winds are expected Sunday Night, they
will form again Monday through Wednesday, with a peak around Tuesday of
gusts between 40 and 60 mph. With humidities plummeting to 5 to 15
percent, there is a high risk for Red Flag Warnings. Moderate confidence
in relief forming by Thursday with a 40 percent of light rain and light
winds for the end of next week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect from 6 AM Saturday to noon PST
      Sunday for zones 340-346-354. (See LAXCFWLOX).
     High Wind Watch in effect from late Saturday night through
      Sunday afternoon for zones 369-375. (See LAXNPWLOX).
     High Wind Watch in effect from Saturday evening through
      Sunday afternoon for zones 379-380. (See LAXNPWLOX).
     Fire Weather Watch in effect from Saturday evening through
      Sunday afternoon for zones
      288-354-355-358-362-369>376-378>380. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 9 AM PST Saturday for
      zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 5 PM Saturday to 3 PM PST
      Sunday for zone 655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PST Sunday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/MW
AVIATION...Gomberg
MARINE...Black/Smith
FIRE...Kittell
SYNOPSIS...MW/Smith

weather.gov/losangeles

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