627
FXUS66 KLOX 121959
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
1159 AM PST Wed Nov 12 2025

.SYNOPSIS...12/937 AM.

Onshore flow and increasing clouds will bring significant cooling
to southwest California today. Periods of moderate to heavy rain
are expected Thursday through Saturday, and possibly into early
next week, as a storm system moves into the region. Quite a bit
of uncertainty in the progression of the storm exists, and
widespread flooding is not out of the question.

&&

.SHORT TERM (TDY-FRI)...12/947 AM.

***UPDATE***

The return of onshore flow will lead to significant cooling across
inland areas today while coastal areas will remain on the cool
side. Lots of mid and high clouds will pass over the area today
but no precipitation is expected until at least Thursday. The
forecast for the next few days remains rife with uncertainty, but
there is the potential for significant rain and flooding
sometime between late Thursday and Monday.

***From Previous Discussion***

Compared to this time yesterday, quite a bit of uncertainty has
been reintroduced into the forecast for the upcoming storm -
especially for the Friday/Saturday time period. This is due to
models significantly changing their tune compared to 24 hours ago,
resulting in a lack of consistency from run to run and model to
model. What we are certain about is it`s going to rain between
Thursday and Saturday (and potentially into Sunday morning), and
there will be periods of moderate to heavy rain. But exactly where
and how much has become a little bit fuzzy again. As usual, its
best to be over-prepared than under prepared. Check to make sure
your gutters are cleared, your windshield wipers are secure, and
try to make alternate plans if your Thursday through Saturday
activities are supposed to be held outdoors. During the rain, do
not drive through flooded roads, as only a few inches of water can
move a car, and make sure to go indoors if you hear thunder.
Listen to any instructions local authorities tell you, and lastly,
make sure you have multiple ways to receive weather related
alerts.

That all being said, today will be benign weather-wise, with
higher clouds streaming across the region. Lowering 500mb heights
and increased onshore flow will continue to lead to widespread
cooling of high temperatures compared to yesterday, resulting in
temperatures in the 60s and 70s. Additionally (an a little bit of
a fun mention), some virga (rain that evaporates before reaching
the ground) may be present out ahead of the storm thanks to the
high clouds and moisture moving into the area.

As for the storm, models are still in disagreement about the
placement, orientation, and timing of this storm, but all of them
do hint at the low pressure system stalling over the waters off
the coast Friday into Saturday. The storm progression is a
little odd, as high-res models show almost a QLCS-like structure
as the front approaches the Central Coast on Thursday, falling
apart near Point Conception, and then rain becoming more
widespread for Santa Barbara to Los Angeles. The best estimate
for when the rain reaches the Central Coast is around mid to late
Thursday morning, late morning into afternoon for Santa Barbara,
and Thursday night into early Friday morning for Ventura and Los
Angeles County. There are some models that suggest that there
could be a break late Friday morning, with a few scattered
showers, and then by the afternoon, rain is re-introduced across
Santa Barbara County south through at least Los Angeles County.
With this progression, rain will favor south-southwest facing
slopes at the start, and then could take on a more south-southeast
approach Friday into Saturday.

With the available moisture being transported into the region
(PW`s about 1.5"), this brings flooding concerns across the
region, especially those south-southwest facing mountain slopes.
While models are still all over the place with exact amounts, they
do show an increase to what they`ve previously suggested, at
least for the mountains. While rain totals of 1-2 inches is most
likely to occur across the coasts and valleys(especially north of
Point Conception), amounts for the mountains and foothills might
be leaning more towards 2-5" (and potentially higher in specific
locations if the storms start to train Friday night into
Saturday).

As for rain rates, sticking with the previous forecast of
widespread rain rates between a quarter and half inch per hour and
locally as much as 0.75/hr. However, there is a 10-20 percent
chance of thunderstorms and locally higher rates may be possible.
While models show this low pressure system not quite as cold as
originally forecast, models suggest some divergence aloft, some
CAPE, combined with storm relative helicity, and decent lifted
indices, resulting in that 10-20 percent chance of thunderstorms.
Any thunderstorm that forms may be accompanied by heavy
downpours, small hail, gusty winds, and/or while not likely, there
is a non-zero (but very small) chance of a weak, brief, tornado.
It`s also possible that an individual cell that moves through
doesn`t even have thunder and lightning, but has any or all of the
above impacts. While there is a threat of thunderstorms with this
storm, it won`t be as widespread or frequent as the storm we saw
during that September storm where lightning continuously lit up
the skies near Santa Barbara.

There could be flooding of roadways, mud and rock slides, heavy
rain that even the fastest speed of windshield wipers can`t keep
up with. Additionally, debris flows in and around the recent burn
scars in Santa Barbara, Ventura, and Los Angeles County, so please
make sure to have multiple ways of receiving alerts if near any
burn scar.

As of now, not much snow is expected with this system except
possibly a few inches, mostly above 8000 feet. If any snow does
fall, it would be in the later period of the storm, during that
Friday-Saturday timeframe.

Lastly, this is a lower confidence situation, as cut off lows in
this region tend to be. However, should these higher totals come
to be true, there could be higher impacts. If the next model runs
trend backward to the previous suggestions, then the impacts will
be less than mentioned in the above. Please make sure to stay up
to date on the forecast.

.LONG TERM (SAT-TUE)...12/351 AM.

As previously mentioned, there is quite a bit of uncertainty in
when the storm will end. Showers could continue through Saturday
afternoon and even into Sunday (as some of the higher resolution
models suggest rain will still be moving through Santa Barbara to
Los Angeles Counties Saturday morning). Ultimately, it is all
dependent on how the low pressure system shifts, and if it
actually stalls over the waters to our west. If the upper low
stalls far enough offshore it could lead to a continuation of
steady moderate to locally heavy rain across the area Saturday
(especially south of Pt Conception) and possibly even into early
Sunday as the initial plume just pivots around the low rather than
progressing east. If the upper low ends up not cutting off and
returns to the original, more progressive pattern from the
previous days, there may be still be some light showers south of
Pt Conception Saturday but much lighter and exiting sooner. The
first (and wetter) scenario is the currently favored option in the
models now but again this is a very low confidence forecast
overall.

The rest of forecast through early next week remains similarly
uncertain given the earlier issues. There are several ensemble
solutions still indicating another cutoff low along the West coast
with a chance of rain Monday and Tuesday.

&&

.AVIATION...12/1942Z.

Around 1850Z, the marine layer depth was around 1000 feet deep at
KLAX. The top of the inversion was near 2200 feet with a
temperature around 20 degrees Celsius.

Moderate confidence in the current forecast for terminals from
KSBA north. Moderate to high confidence in the current forecast
for terminals from KSBA south.

High MVFR to VFR conditions will continue through 20Z, then VFR
conditions will develop after 20Z and continue through at least
03Z Thursday. There is a moderate chance of MVFR conditions after
03Z at coastal terminals. Otherwise, ceilings at or below 6000
feet will likely become prevalent after 06Z Thursday for
terminals north of Point Conception with MVFR conditions in rain
showers developing after 12Z Thursday.

Periods of moderate to strong low-level wind shear and turbulence
are possible at terminals north of Point Conception after 14Z
Thursday.

KLAX...There is a 30 percent chance of periodic MVFR conditions
through 07Z Thursday, otherwise VFR conditions will likely
persist. MVFR conditions should develop by 09Z at the latest with
chances increasing to above 60 percent. No wind impacts are
expected at this time.

KBUR...VFR conditions are expected through the period, but there
is a 10 percent chance of MVFR visibilities after 08Z Thursday.
No wind impacts are expected at this time.

&&

.MARINE...12/854 AM.

High confidence in the current forecast for impacts. Moderate
confidence in the current forecast for timing. A storm system
will make its way into the coastal waters between Thursday and
Thursday night. This storm will bring a slight chance of
thunderstorms across the entire waters through at least Saturday
morning. Any thunderstorms that develop will be capable of
producing frequent lightning, gusty and erratic winds, locally
rough seas and even waterspouts.

There is a likely-to-imminent (70-100 percent) chance of widespread
Small Craft Advisory (SCA) conditions as soon as this afternoon or
tonight moving from northwest to southeast across the waters west
through northwest of Point Conception. There is a high to likely
(40-70 percent) chance for Gale Force winds for the waters west
through northwest of Point Conception from late tonight through
Thursday evening. Steep short period seas will build to hazardous
levels throughout the day on Thursday, then likely decrease to
below 10 feet after Saturday morning.

Inside the California bight, winds and seas will begin to increase
Thursday night. SCA level south-southeast winds (20-30 knots)
will be common through Friday afternoon with steep short-period
seas likely, highest across the Santa Barbara Channel.

Winds and seas should begin to improve Saturday through the
weekend. However, rain and thunderstorm chances will linger into
Sunday.

&&

.BEACHES...12/1231 AM.

A storm system will usher in a large west-northwest moderately
long period swell to the coastal waters Thursday through
Saturday. High Surf Advisories are likely for all coastal areas.
However the southern Santa Barbara County beaches may only need a
Beach Hazards Statement. Highest surf will occur along west and
northwest facing beaches. At this time, peak tides are around 5
feet, so coastal flooding is not expected to be a significant
issue. Although there a low chance for beach erosion and minor
coastal flooding along the Central Coast Friday morning.

Peak Surf Heights:
Central Coast - 12 to 16 feet
Southern Santa Barbara County - 4 to 6 feet with local sets to 7
feet
Ventura County - 8 to 11 feet
Los Angeles County - 4 to 7 feet

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect from 9 PM this evening to 8 AM
      PST Thursday for zone 645. (See LAXMWWLOX).
     Gale Watch in effect from Thursday morning through Thursday
      afternoon for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 4
      AM PST Thursday for zone 670. (See LAXMWWLOX).
     Gale Watch in effect from late tonight through Thursday
      afternoon for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 9 PM this evening to 3 AM
      PST Saturday for zone 673. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 AM Thursday to 3 AM PST
      Saturday for zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Lund
AVIATION...Hall
MARINE...Hall
BEACHES...Lewis
SYNOPSIS...MW/KL

weather.gov/losangeles

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