970
FXUS66 KLOX 101725
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
925 AM PST Mon Nov 10 2025

.SYNOPSIS...10/910 AM.

Today will be very warm and dry, especially across the Los
Angeles and Ventura County valleys. A cooling trend will start
Tuesday, ahead of the incoming storm system. Rain may start as
early as Wednesday night, however the heaviest rainfall is likely
to occur Thursday morning into Thursday night. Dry but cool weather
is expected over the weekend.

&&

.SHORT TERM (TDY-WED)...10/924 AM.

***UPDATE***

Another very warm day across the valleys and interior areas today
due to a 4mb offshore flow and a 591dam high pressure system over
the region. A trickier pattern towards the coast as there is a
very strong 500` marine layer in place and low clouds are hugging
most of the coastline, and in some cases 1-2 miles inland causing
some very dense fog. With essentially zero upper support it`s
likely that coastal areas will remain mostly in the 60s to low
70s, but any coastal hills will warm up quickly and significantly
above 500` so anyone doing any recreation in those areas should be
prepared for temps quickly rising into the 80s and even some 90s.

***From Previous Discussion***

On Tuesday, a significant cooling trend will start up as the
onshore gradients start to increase and the 500mb heights start to
drop. Most areas will see a 5-10 degree drop in temperatures both
Tuesday, and again Wednesday. The marine layer will also deepen
as a result of the onshore trends and lowering heights, and low
clouds will likely push back into the valleys by Wednesday
morning.

.LONG TERM (THU-SUN)...10/321 AM.

While still outside the high resolution model window, the EC and
GFS as well as their ensembles are somewhat coming into agreement
as well as the very end of the NAM window for the upcoming storm.
Timing wise, Thursday looks to be the main period for rain,
though there`s about a 12 hour window where the models disagree on
start times, with the NAM on the earlier side, bringing rain
across the Central Coast as early as Wednesday evening, and the
GFS and EC leaning towards the late Wednesday night to early
Thursday morning time period. Regardless of the start time, the
models do suggest that the front moving through will bring a
heavy, but relatively short period of rain, falling within about
5-10 hours.

Like many of the systems we get in SoCal, orographics will play a
role with south-southwest facing upslope areas getting twice to
three times the amount of rain at coasts. With the GFS and its
ensemble members showing rain totals slightly lower than the EC
and its ensemble members (which seems to be more often than not),
still leaning toward the previous forecast of rain totals of 1-2
inches across coasts and valleys and 2-4 inches across foothills
and mountains. As for rain rates, between a quarter and half
inch per hour rates are possible, with as much as 0.75 per hour in
the upslope areas. However, there remains a 30 percent chance for
higher totals than what is forecast. Especially as there is a
possibilty for convection as this system is cold, models are ever
so slightly hinting at upper level divergence, and the upper
level jet overhead. If convection does come to be a factor, rain
totals and rates could be locally higher wherever an individual
cell may form.

Snow levels will likely remain at or above 8000` for most of the
storm, then drop to around 6000 feet as the last of the precip is
moving through later Thursday night into Friday morning. At this
point it does not appear to be cold enough for snow on the
Grapevine, but some light accumulations (2-4") are possible down
to around 6000`.

Dry and cool weather expected next weekend with highs mostly in
the upper 60s to low 70s.

Additionally, looking out ahead to early next week, another storm
could be on the tails of the one at the end of this week. However,
early model projections at this time, do show the storm would be
lighter.

&&

.AVIATION...10/1654Z.

At 1630Z at KLAX, the marine layer was 400 feet deep. The top of
the inversion was near 1600 feet with a temperature of 27 degrees
Celsius.

For 18Z TAF package, high confidence in CAVU conditions for KPRB,
KBUR, KVNY, KWJF and KPMD.

For coastal sites, moderate confidence in 18Z TAFs due to
uncertainties in behavior of marine layer. Current forecasts of
flight category changes could be +/- 3 hours of current
forecasts.

KLAX...Moderate confidence in 18Z TAF. Timing of flight category
changes could be +/- 3 hours of current forecasts. No significant
easterly wind component is expected.

KBUR...High confidence in 18Z TAF.

&&

.MARINE...10/854 AM.

For the entire coastal waters, high confidence in winds and seas
remaining below Small Craft Advisory (SCA) levels. By Wednesday
night and Thursday, southerly winds ahead of the incoming storm
system will pick up, reaching SCA levels across most of the
coastal waters. After the front passes Thursday, SCA level
northwest winds are expected with the SCA level winds continuing
into Friday night or Saturday morning. Additionally, there will be
a 40-50% chance of Gale force winds Thursday through Friday across
the coastal waters south of Point Conception.

Along with winds, the aforementioned storm system will bring
large, rough seas to the Coastal Waters Thursday afternoon through
late Friday night, including 8-10 foot seas for the inner waters
south of Point Conception. There is also a chance for
thunderstorms with frequent lightning and potential waterspouts
with the frontal passage. Thunderstorms can also create sudden,
intense wind shifts.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...MW/Lund
AVIATION...RAT
MARINE...Lewis/RAT
SYNOPSIS...MW/Schoenfeld/KL

weather.gov/losangeles

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