322
FXUS66 KLOX 111120
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
320 AM PST Tue Nov 11 2025

.SYNOPSIS...11/315 AM.

Onshore flow will return to the region today as a ridge of high
pressure continues to weaken and shift eastward. A shallow marine
layer will bring dense fog at times to the coast, possibly
reaching the valleys by Wednesday morning. A trough of low
pressure will approach the West Coast on Wednesday night and bring
rain, heavy at times through Thursday night or Friday. Drier but
cool weather is expected over the weekend.

&&

.SHORT TERM (TDY-THU)...11/319 AM.

The ridge of high pressure aloft has finally started weakening
and shifting towards the east. As the ridge moves out of the area,
SW flow aloft will return as well as pressure gradients switching
to onshore. Wednesday night through the week, an upper level
trough of low pressure will move over the region bringing rain
and a slight chance of thunderstorms to much of the area.

High clouds will be prevalent across the region today and
Wednesday out ahead of the aforementioned trough. Despite these
high clouds, the onshore flow and high 500mb heights has allowed
the marine layer clouds and dense fog to spread across the coasts,
and a dense fog advisory is in effect until 9am for these areas
(as well as the L.A. County Inland Coast). As the morning
continues, the dense fog and low clouds will retreat to the
beaches, but may remain at the coasts thanks to the increasing
onshore flow. As the onshore flow strengthens and the 500mb
heights lower today and Wednesday, marine layer stratus will
deepen and likely penetrate further into the coasts and valleys
overnight tonight (with the valleys possibly seeing dense fog, and
some improved visibilities closer to the coasts). Additionally,
temperatures will cool both today and Wednesday compared to the
previous day, by about 7 to 12 degrees. This will drop high
temperatures into the 70s and 80s away from the coast today, and
in the 70s by Wednesday.

A moderate to strong storm with PW`s around 1.5" is expected to
move through the region during the latter half of the week. Could
see some light precip as early as Wednesday night along the
Central Coast and a few post- frontal showers Friday, but 90% of
the rainfall should take place on Thursday. Most areas will
experience around 6-8 hours of precip with the front, 1-3 hours of
which could be heavy with up to 0.75" per hour and a 20% chance
of as much as 1.00" per hour. The heaviest precip will be in
the usual favored upslope areas, including the Santa Lucia`s, the
Santa Barbara mountains (particularly the Santa Ynez Range) into
the western Ventura County mountains, the Santa Monica mountains,
and the eastern San Gabriel mountains. All of those areas will be
at risk for heavy rain and flooding. If models stay consistent
it`s likely that a Flood Watch will be issued for the most
vulnerable areas, including the most recent burn scars. Projected
total rain amounts remain about the same with most coastal/valley
areas falling into the 1-2" range with foothills and south facing
mountains in the 2-4" range. But would not be surprised to see a
couple 5" totals when all is said and done. Additionally, there is
a slight chance of thunderstorms along San Luis Obispo and Santa
Barbara counties on Thursday, and most of the region by Friday
morning. Any thunderstorm that may form may be accompanied by
lightning, locally gusty winds, heavy downpours, and/or small
hail.

Not expecting any snow below 8000 feet with this system until the
very tail end of it, when there could be a few inches between
6000-8000 feet.

.LONG TERM (FRI-MON)...11/253 AM.

There is still some uncertainty with regard to how long showers
will continue following the main cold front on Thursday. The
latest ensembles place the trough right through LA County Friday
morning with northwest flow developing during the afternoon and
evening. There still could be some brief moderate to locally heavy
showers before the trough passage Friday morning but most of the
ensembles are indicating rain rates well below a half inch per
hour after 4am Friday. Some of the ensemble members of both the
GFS and EC hint at rain continuing over the weekend, (which may
just be why the NBM is carrying slight chances of rain over the
entire weekend), however the majority of ensemble members suggest
the rain is over before the day changes to Saturday.

Therefore, dry but cool weather is expected over the weekend.
There remains a small chance of a weak storm next Monday but
recent model runs have backed off that system.

&&

.AVIATION...11/1115Z.

At 0805Z at KLAX, there was a surface inversion. The top of the
inversion was near 1500 feet with a temperature of 25 degrees
Celsius.

High confidence in VFR conditions for KPRB, KBUR, KVNY, KWJF and
KPMD. 15% chance for VLIFR conds at KPRB through 17Z.

Moderate confidence in all coastal sites. Timing of clearing may
be off +/- 3 hours, and there is a 30% chance immediate coastal
sites do not clear. Moderate confidence in return of cigs after
12/00Z, but low confidence in timing (+/- 4 hours) and minimum
flight cat (off +/- one cat). Expecting slightly higher cigs and
vsbys at most locations later tonight.

KLAX...Low to moderate confidence in TAF. Clearing may be off by
+/- 3 hours, but there is a 30% chance for no clearing. Arrival of
low clouds tonight may be off +/- 4 hours. Low confidence in
minimum flight cat, but moderate confidence in slightly improved
conditions. No significant east wind component is expected.

KBUR...High confidence in TAF.

&&

.MARINE...11/150 AM.

Dense fog with visibilities less than one nautical mile will
continue to be an issue for all the coastal waters through late
this morning.

High confidence in relatively calm winds and seas through
Wednesday, except for localized Small Craft Advisory (SCA) level
wind gusts to 25 knots near Point Conception and south to San
Nicolas Islands early this morning, and again this afternoon and
evening. Southwest winds 20-30 knots will develop Wednesday
afternoon across the outer waters as well as nearshore along the
Central Coast. Southerly winds across the inner waters south of
Point Conception will be in the 15-20 knot range, but SCA level
gusts to 25 knots cannot be ruled out.

A cold front from a storm system will pass through the region
Thursday and gusty northwesterly winds of 20-30 knots will develop
across the entirety of the coastal waters. There is a 30% chance
for low end Gale Force winds Thursday afternoon through late
Friday, including across the inner waters south of Point
Conception. Seas across the outer waters will increase to 12-14
feet, and 5-7 feet inside the Southern California Bight.

From Wednesday night through Thursday, the aforementioned storm
system will bring a slight chance of thunderstorms across the
coastal waters from the Santa Barbara Channel northward. Any
thunderstorms that develop will be capable of producing frequent
lightning, gusty and erratic winds, locally rough seas and even
waterspouts.

Moderate confidence in conditions improving some over the weekend,
but SCA winds are still possible, especially across the outer
waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Dense Fog Advisory remains in effect until 9 AM PST this
      morning for zones 340-341-346-347-350-354-355. (See LAXNPWLOX).
     Dense Fog Advisory in effect until 9 AM PST this morning for
      zones 349-362-366-368. (See LAXNPWLOX).
PZ...NONE.

&&

$$

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

weather.gov/losangeles

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