134
FXUS66 KLOX 051644
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
944 AM PDT Sat Sep 5 2026

.SYNOPSIS...04/225 PM.

Tropical Cyclone Marie, which will remain well offshore of SoCal,
will bring impacts to the region over the weekend into early next
week. Rain is favored late Saturday and Sunday focused over Los
Angeles and Ventura Counties. Increasing southerly swell will
create hazardous surf conditions at the coasts.

&&

.SHORT TERM (TDY-MON)...05/943 AM.

***UPDATE***

Mid and high level clouds sent by Hurricane Marie will spread into
the area today. As for rain impacts, the high resolutions models
are generally in agreement that rain will start early Sunday
morning and last into the evening. Rain is expected to be focused
over Los Angeles County, mostly likely the eastern portion. Rain
totals are favored to be 0.25 inches or less for most areas in LA
county, except high amounts in the foothills of the San Gabriel
Valley (0.5 inches likely) and the eastern San Gabriel Mountains
(locally around 1.0 inch). Rain totals will generally be 0.10
inch or less for Ventura County northward. Rain rates will be
light to moderate, topping out around 0.25 in/hr for most
locations. Local heavier showers with rain rates briefly 0.33-0.50
in/hr will be possible, especially for the eastern San Gabriel
Mountains.


***From Previous Discussion***

Hurricane Marie was 850 NM due south of Los Angeles, and is
forecasted to travel in the northwest to north direction over the
next several days while weakening. Marie will remain well
offshore of the California Coast, but will still be able to send
some weather impacts to SoCal this holiday weekend and possibly
beyond. Some of the most significant hazards from Marie will be
seen across the beaches where very hazardous ocean swimming
conditions are expected for the Labor Day holiday weekend.
Potentially deadly rip currents and high surf is expected for
south-facing beaches. Please consider swimming near a lifeguard
and follow their guidance. Additionally, moderate coastal flooding
and coastal erosion is expected for vulnerable south-facing
beaches. See the beaches section below for details on the coastal
hazards.

We will begin seeing mid to high clouds increase from the south
this afternoon into evening, a prelude of unseasonably unsettled
weather setting up for late tonight and especially into Sunday
focused in LA and Ventura Counties, but possibly spreading into
Santa Barbara County at times.

A small-scale perturbation on the eastern peripheral of Hurricane
Marie will move northward due to mainly the interaction of large-
scale troughing situated along the west coast. This is a very rare
pattern for our part of the country, especially in early
September, as a strong (for early september), favorable part of a
jet stream peaking near 120 kt interacts with the tropical
moisture (precipitable waters may reach incredible values of 2
inches across LA and Ventura Counties) with improving mid-level
lapse rates to support scattered mainly light to moderate showers.
However, there is a 5 percent chance of excessive rainfall with
minor flooding in embedded heavier showers or thunderstorms (5-15
percent chance) focused across the LA County into eastern Ventura
County. While any embedded heavier showers or thunderstorms will
mostly be moving at decent pace, any stalled or training cells
could produce rainfall in excess of a quarter of an inch in an
hour. Rainfall totals as a whole will be less than a half of an
inch (probably under a quarter of an inch where most people live),
focused across LA and possibly eastern Ventura County, isolated
higher amounts will be possible, especially coastal facing
mountains. The roads will be quite slick with any wetting rainfall
due to the build up of oils over the last many months.

Temperatures will feel warmer over the weekend with the additional
humidity but still remain within a few degrees of normal.
Overnight lows could be quite warm and only into the 70s for our
southern coasts and coastal valleys where the topical mositure
will be the greatest.

Monday will warm some with continued humid conditions potentially
posing moderate Heat Risk, especially near the coast where balmy
ocean temperatures continue down south. Isolated showers or even
a thunderstorm or two may continue into Monday as lingering
impressive moisture near 1.5 in precipitable water will overlap
with better destabilization sunshine.

.LONG TERM (TUE-FRI)...05/301 AM.

Extremely low forecast confidence for Tuesday and beyond as what
will likely be the remnants of Marie plays tricks with our model
guidance.

Exactly when and how Marie or its moisture merges with an
unseasonably far south jet stream will determine what version of
weather and associated impacts we receive.

Two main scenarios seem to be emerging:
1) The remnants of Marie remain well offshore (80 percent
chance). Even if this occurs continued moist south to southeast
flow main bring light showers or isolated thunderstorms focused
across interior mountains to deserts at times. This scenario has
the greatest chance (50-60 percent chance) of a mid-week heatwave,
potentially warranting heat products.

2) The remnants of Marie make a somewhat closer pass (20 percent
chance), and bring widespread at least light to moderate rain in
the Tuesdayish timeframe, especially Santa Barbara and San Louis
Obispo Counties.

Please stay tuned if heat and/or rain may impact your plans next
week as things will change.

&&

.AVIATION...05/1637Z.

At 1600Z at KLAX, the marine layer was 1300 feet deep. The top of
a weak inversion was 2600 feet with a temperature of 20 degrees
Celsius.

For 18Z TAF package, high confidence in CAVU conditions for all
sites through this evening. Overnight, moderate confidence in
current forecasts as tropical moisture moves in, bringing the
threat of light showers and could wreak havoc with stratus
formation.

KLAX...Moderate confidence in 18Z TAF. CAVU conditions are
expected through this evening. Overnight and through Sunday,
there is a 30-40% chance of MVFR CIGs. Light showers are expected
to develop Sunday morning. No significant easterly wind component
is expected.

KBUR...Moderate confidence in 18Z TAF. CAVU conditions are
expected through this evening. Overnight and Sunday morning, there
is a 20-30% chance of MVFR CIGs. Light showers are expected to
develop Sunday morning.

&&

.MARINE...05/937 AM.

For the Outer Waters, moderate confidence in current forecast.
There is a 20-30% chance of Small Craft Advisory (SCA) level
winds through tonight. For Sunday, there is a 60-80% chance of
SCA level winds. For Monday through Wednesday, there is a 30-40%
chance of SCA level winds.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. High confidence in winds and seas
remaining below SCA levels through tonight. On Sunday and Monday,
there is a 30-40% chance of SCA level winds in the afternoon and
evening hours. For Tuesday and Wednesday, high confidence in winds
and seas remaining below SCA levels.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. For a majority of the southern
Inner Waters, high confidence in winds and seas remaining below
SCA levels through Wednesday. The only exception will be the
western half of the Santa Barbara Channel where there will be
50-60% chance of SCA level winds late Sunday afternoon and
evening.

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...05/937 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 5-8 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 on Sunday and 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
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...NONE.

&&

$$

PUBLIC...Munroe/Schoenfeld/Black
AVIATION...RAT
MARINE...RAT
BEACHES...RAT
SYNOPSIS...Lewis/RS

weather.gov/losangeles

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