963
FXUS66 KLOX 121155
AFDLOX

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

.SYNOPSIS...12/355 AM.

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

&&

.SHORT TERM (TDY-FRI)...12/345 AM.

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 overprepared 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 scatterd 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
indicies, 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.

Flood Watches may be issued on the dayshift, should the models
continue to trend toward the low pressure system stalling
resulting in higher rain totals south of Point Conception. 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...12/1149Z.

At 0757Z at KLAX, the marine layer was 1000 feet deep. The top of
the inversion was near 2300 feet with a temperature of 21 degrees
Celsius.

Moderate to high confidence in TAFs for KPRB, KBUR, KVNY, KPMD,
and KWJF. There is a 15% chance for LIFR to IFR conds at KPRB,
KBUR, and KVNY through 17Z.

Moderate mostly IFR conds at coastal sites, with cigs bouncing in
and out of sites as high clouds disrupt the formation of the
marine layer clouds. Clearing times may be off +/- 3 hours. There
is a 30% chance for MVFR low clouds after 00Z tonight at all
coastal locations.

SHRA may begin at KPRB and KSBP as early as 06Z, but the bulk of
the rain will reach the terminals between 18Z and 22Z, then will
work its way south, eventually impacting all sites.

KLAX...Moderate confidence in TAFs. Low clouds may SCT at times
through this morning. Clearing time may be off +/- 2 hours. For
tonight, there is a 30% chance for OVC010-020 cigs after 07Z, but
confidence is low. No significant east wind component is
expected.

KBUR...Moderate confidence in TAF. 15% chance for LIFR to IFR
conds through 17Z.

&&

.MARINE...12/125 AM.

Beginning Thursday, a storm system will make its way into the
coastal waters Thursday. This storm will bring a slight chance of
thunderstorms across the entirety of the coastal 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.

High confidence in a combination of Small Craft Advisory (SCA)
level winds and seas increasing as soon as this afternoon across
the northern Outer Waters, then expanding to the south and east
(including nearshore) through the night. There is a 30% chance for
Gale Force winds for the waters adjacent to the Central Coast
from Morro Bay northward, including nearshore, from late tonight
through Thursday evening. Seas will build Thursday, peaking at
12-16 feet late Thursday into Friday morning, then decreasing to
below 10 feet Saturday morning.

Inside the California bight, winds and seas will begin to increase
Thursday night. SCA level souht-southeast winds (20-30 knots)
will be common through Friday afternoon. Seas will peak in the 5-7
foot range, highest across the Santa Barbara Channel.

For the entirety of the coastal waters, very low confidence in
wind directions as the storm system (upper level low pressure
system) is forecast to stall and spin above Point Conception.
Winds may be from the SE to the N depending on the location of the
aforementioned upper level low.

Winds and seas will 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...NONE.

&&

$$

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

weather.gov/losangeles

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