374
FXUS66 KLOX 061855
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1155 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)...06/921 AM.

***UPDATE***

Light to moderate rain is occuring for much of Ventura and Los
Angeles Counties. Totals so far for LA County are mostly 0.10 to
0.33 inches with some spots exceeding 0.50 inches in the Santa
Monica Mountains. Rain will continue through the day, and locally
heavier bands of rain will be possible. The peak time period for
rain and rainfall rates looks to be between around 10 AM to 4 PM
today. Widespread rain totals between 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 (Santa Monica Mountains and San Gabriel
foothills) and where orographic lift enhances rain amounts. There
will continue to be a 10 percent chance of mainly minor flooding
impacts (bumped from 5 percent with the update to the forecast
around 5 AM).

***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...06/1853Z.

At 1824Z at KLAX, the marine layer was 700 ft deep with a very
weak inversion up to 2000 ft with a maximum temperature of 20 C.

Rain or showers are expected for Ventura and Los Angeles County
TAF sites through the day today, likely ending between 22Z Sun and
02Z Mon. Ceiling heights will mostly be VFR with period of MVFR,
though VSBY may fall to 1-2SM briefly during heavier showers.
There is also a 5-15 percent chance of a thunderstorm for Ventura
and Los Angeles TAF sites, until around 00Z Mon.

KLAX...Moderate confidence in TAF. Cigs will generally be between
BKN025-BKN100 for the day, and VSBY falling to as low as 2SM
occasionally with heavier rain through around 02Z Mon. East wind
component exceeding 8 kts is possible (40% chance) through 23Z,
and confidence is generally low in wind direction until 00Z Mon.

KBUR...Moderate confidence in TAF. Cigs will generally be between
BKN025-BKN100 for the day, and VSBY falling to as low as 2SM
occasionally with heavier rain through around 02Z Mon.

&&

.MARINE...06/922 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 today through
Tuesday, bringing the threat of showers to the coastal waters.
There is a 15% chance of thunderstorms this 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...06/923 AM.

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 until 9 AM PDT Monday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

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

weather.gov/losangeles

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