796
FXUS66 KLOX 061239
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
539 AM PDT Sun Sep 6 2026

.SYNOPSIS...06/410 AM.

Tropical Cyclone Marie, which will remain well offshore of SoCal,
will bring impacts to the region through at least early next
week. Rain is favored early Sunday morning into the evening,
focused over Los Angeles and portions of Ventura Counties. A
significant southerly swell will create hazardous surf conditions
at some coasts.

&&

.SHORT TERM (TDY-TUE)...06/538 AM.

***UPDATE***

Moderate to locally heavy bands of showers have already pushed
into LA County with already around a tenth of an inch within 30
minutes in some spots. With this early activity and much activity
still upstream over the Pacific Ocean, will adjust expected
rainfall amounts and rates upward more inline with the RRFS model,
especially across Los Angeles. Its now looking likely that
widespread 0.25-1 inches is likely at least across much of Los
Angeles County, but these amounts could spill into eastern Ventura
County. Local amounts of around 1.5 inches is now looking more
probably in favorable south facing foothill locations and where
heavier banding of showers is more consistent. The message below
has been updated accordingly, including bumping up to a 10 percent
chance of mainly minor flooding impacts.

***From Previous Discussion***

Ahead of jumping into unseasonably unsettled weather for many
areas, we want to continue to emphasize the ongoing large and
potentially deadly surf and rip currents focused across south and
southwest facing beaches with minor flooding also possible at the
coast. If entering the ocean, we recommend swimming near a life
guard. This threat continues through at least Tuesday, please see
associated coastal hazards for details.

Still squarely in our climatologically dry season, we will likely
see anything but that today, especially Los Angeles and eastern
Ventura County. Hurricane Marie was 770 miles south southwest of
Los Angeles continue on a steady northwest track. Marie will
remain well offshore while continuing to weaken over the next
several days, although it is partially responsible for the
unseasonably wet conditions today and potentially into times next
week.

Showers were already expanding in coverage across far southern
California with expanding and cooling cloud tops indicative of
organizing showers offshore to our south. With the unsettled
weather now on our doorstop we have increasing confidence of
widespread rainfall covering at least much of Los Angeles and
Ventura Counties. Rain will likely start early to mid morning
across many of these areas with increased likelihood of embedded
moderate to heavy showers and isolated thunderstorms (5-15 percent
chance) with a 10 percent chance of excessive rainfall leading to
minor flooding or debris flows in steep terrain (especially near
recent burn scars) and street flooding in urban areas. Ingredients
that give us moderate confidence in this scenario include Mid-
level lapse rates increasing to modest values of 6 deg C/km with a
very strong (for this time of year) and favorable portion of a
jet streak will combine with a tropical airmass (near record
precipitable water values around 2 inches) that we are
unaccustomed to in Southwest California.

Rain totals of a 0.25 to 1 inches will be common where most
consistent banding of showers and isolated thunderstorms occur,
which is still looking likely in Los Angeles into eastern Ventura
County. Isolated totals up to 1.5 inches is possible especially
coastal foothills or where training of heavier showers occurs.
There is a 10 percent chance of rainfall rates of 0.25-0.5 inches
per hour (much of which could fall in about 30 minutes), which
could cause some flooding issues, especially in sensitive areas.
In addition to minor roadway flooding concerns, roads could become
slick and dangerous due to the buildup of oil after many dry
months.

A weak impulse acting on lingering low level moisture may
instigate isolated to scattered additional showers this evening or
even early overnight. Otherwise clearing is expected and areas
with decent rain could see patchy dense fog develop by early
Monday morning. A boundary lifting back north later Monday and
especially into Tuesday may support another round of light to
moderate showers just about anywhere. Cannot rule out an isolated
thunderstorm focused across interior mountains.

Heat impacts will continue to be on the increase through Monday or
Tuesday with moderate heat risk likely in some areas due to added
humidity elevated overnight low temperatures and daytime highs
also increasing where we get decent daytime sunshine.

.LONG TERM (WED-SAT)...06/411 AM.

Moderate confidence that we will see a warming trend into
Wednesday with moderate to high heat impacts possible Wednesday
into Thursday or Friday with increasing potential of at least some
heat products in this window. The position of the ridge by
Thursday may be favorable for monsoon moisture or injection of
tropical moisture from the south. So it will likely be quite humid
with weak morning offshore flow potentially delaying the sea
breeze, potentially bringing dangerous heat impacts close to
coast. This type of pattern could support isolated showers or
thunderstorms focused across the interior.

Below normal confidence Friday into next weekend as the ridge may
break down pretty quickly or be somewhat stubborn. Either way it
does look somewhat likely that troughing off the coast may
reestablish at times, keeping the door open for additional
tropical or monsoon moisture to shuttle into southwest California.

&&

.AVIATION...06/1216Z.

At 06Z at KLAX, the marine layer was 600 feet deep. The top of an
inversion was 800 feet with a temperature of 25 deg C.

High confidence in VFR conds KSBA and north with a 10-20 percent
chance of IFR/LIFR cigs/vsbys for KSMX through 16Z. There is a
10-20 percent chance of -shra for KSBA focused between 15Z-20Z.

Moderate confidence in rain timing and coverage elsewhere although
vis in particular could dip to 1-2sm in any brief heavier
showers. There is also a 5-15 percent chance of a thunderstorm in
all TAFs that have shra with the best potential between 18Z-00Z.

Deep tropical moisture could support low clouds at just about any
level, especially in or following brief heavier showers, although
VFR to MVFR cigs should prevail.

KLAX...Moderate confidence in TAF. MVFR to occasionally IFR vis
and mainly VFR to MVFR cigs in any heavier showers. East wind
component of 3-6 kts possible near the onset of rain through
18-20Z with a 10 percent chance of briefly reaching 8 kts.

KBUR...Moderate confidence in TAF. MVFR to occasionally IFR vis
and mainly VFR to MVFR cigs in any heavier showers.

&&

.MARINE...06/1204 AM.

For the Outer Waters, moderate to high confidence in current
forecast. This afternoon through Monday, there is a 60-80% chance
of SCA level winds. For Tuesday and Wednesday, high confidence in
winds and seas remaining below SCA levels. On Thursday, there is
a 30-50% chance of SCA level winds.

For the Inner Waters north of Point Sal, high confidence in winds
and seas remaining below SCA levels through Thursday.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. Through Wednesday, high
confidence in winds and seas remaining below SCA levels. On
Thursday, there is a 30-50% chance of SCA level winds across
western sections.

Tropical moisture will stream over the area Sunday through
Tuesday, bringing the threat of showers to the coastal waters.
There is a 15% chance of thunderstorms Sunday afternoon for the
waters south of the Channel Islands. A large southeast to south
swell will also impact the area, causing increased currents and
surges in the vulnerable harbors.

&&

.BEACHES...05/809 PM.

Significant coastal impacts are expected across Southern
California beaches this Labor Day weekend. A large southeast to
south swell from Hurricane Marie will move into the coastal
waters this weekend with swell heights of 5-7 feet and a period
around 13 seconds.

High surf conditions are expected on south-facing beaches of
Ventura and Los Angeles counties, peaking at 5-8 feet with local
sets to 10 feet through Monday. The Santa Barbara South Coast
will be largely protected from this swell, but there are some
small windows of southeasterly and southwesterly energy that could
cause boosts in the waves. HIGH SURF ADVISORIES remain in place
for Los Angeles and Ventura Counties, with BEACH HAZARDS
STATEMENTS (a step below high surf advisories) in effect for Santa
Barbara and San Luis Obispo Counties.

High tides will also be increasing through early next week. Due to
a variety of reasons, the actual observed tides have been running
about 6 inches above predictions for sometime now. The south
swell will likely boost that enhancement. As a result, high tides
should exceed 7 feet by Monday. Adding large tides with the south
swell will result in a moderate risk for coastal flooding over the
vulnerable south-facing shores. Areas of most concern include
Avalon, Long Beach (Alamitos Peninsula), and Oxnard to Malibu
(including Point Mugu). COASTAL FLOOD ADVISORIES remain in effect
for Los Angeles and Ventura Counties where the best combination of
tides and waves will occur, but Santa Barbara and San Luis Obispo
Counties could also see some isolated issues.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory in effect until 11 PM PDT Tuesday for
      zones 87-354-362-366. (See LAXCFWLOX).
     High Surf Advisory in effect until 11 PM PDT Tuesday for
      zones 87-354-362-366. (See LAXCFWLOX).
     Beach Hazards Statement in effect through Tuesday evening for
      zones 340-346-349-350. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect from 3 PM this afternoon to 9
      AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Munroe
AVIATION...Munroe
MARINE...RAT/KL
BEACHES...RAT
SYNOPSIS...RM/RS/Ciliberti

weather.gov/losangeles

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