Duarte Weather

641
FXUS66 KLOX 072134
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
234 PM PDT Mon Sep 7 2026

.SYNOPSIS...07/1252 PM.

A significant southerly swell will cause hazardous surf
conditions at the beaches through at least Tuesday. Isolated
showers will continue at times through Tuesday. Heat will build
across the region going forward, with moderate to major heat
impacts focused over the coasts and valleys Tuesday through at
least Thursday.

&&

.SHORT TERM (TDY-THU)...07/234 PM.

Now that the main rain event from Tropical System Marie is behind
us, the focus of the forecast pivots to the the upcoming heat
event. While remnants of Marie will remain well off the
California Coast over the next few days, a ridge of high pressure
will build into the region from the east over the next several
days. Temperatures will trend upwards each day through Wednesday,
when 500 mb heights and the light offshore winds will peak. For
most areas Wednesday will be by far the warmest day of the event,
most noticeably along the Central Coast including Santa Maria and
San Luis Obispo, except the Santa Barbara South Coast may see the
warmest temperatures on Thursday due to an increase in Sundowner
winds in the area.

Heat Advisories are in effect Tuesday through Thursday for Los
Angeles County beaches and coastal valleys, and the Santa Monica
Mountains. Wednesday Heat Advisories are expanded to include the
Ventura County coasts and valleys, the Santa Clarita Valley, and
all of Santa Barbara and San Luis Obispo Counties. Widespread
highs will peak in the 90s (including near some coasts) to low
100s. Due to Marie`s influence on the area, humidity will be
elevated which will significantly increase the HeatRisk and
discomfort. The moisture will impact overnight low temperatures,
which will remain very warm (widespread 70s with even some 80s in
the foothills). Mid and high cloud coverage will serve to moderate
heat impacts at times, and the overall event will be relatively
short compared to other heatwaves we have seen so far this summer. This
heat may feel comparable or even slightly worse to recent heat
waves, especially near the coast. Those working or recreating
outdoors as well as those without air conditioning are advised to
follow the forecast, stay hydrated, and seek cooling centers when
possible. There is around a 20-30 percent chance of the Heat
Advisories being upgraded to Extreme Heat Warnings on Wednesday.
This will depend some on the anticipated cloud coverage. The
coastal areas along the Central Coast are of particular concern on
Wednesday, where temperatures may reach 100 degrees or higher for
some locations (20+ degrees above normal).

Tropical Storm Marie is currently centered 750 miles southwest of
Los Angeles, continuing its northwest movement well offshore of
southern California. Even so, moisture and south swells remain in
the area. There is an ongoing, significant hazard across south
facing beaches, with strong and potentially deadly rip currents
(see coastal hazards for details). As for more rain, there is a
slight chance (5-15%) of thunderstorms focused over LA and Ventura
County through this afternoon, and then tomorrow focused over
Ventura Santa Barbara Counties and the Central Coast (and coastal
waters). This is due to the very high PWATs brought into the
region by Marie, combined with any sources of lift. Minor
scattered shower are possible through Tuesday. Then by Wednesday,
shower and thunderstorm activity will likely become confined to
the highest mountains as the strengthening ridge caps and slightly
dries out mid-levels of the atmosphere.

.LONG TERM (FRI-MON)...07/226 PM.

There is the potential for Heat Advisories to be extended on
Friday, however there is high uncertainty for this time period.
Ridging is favored to continue for the area on Friday, but 500 mb
heights will not be as high as previously, and onshore flow will
be stronger thus increasing the cooling seabreeze. By the weekend,
near normal temperatures appear likely. Troughing off the coast
may reestablish at times, keeping the door open for additional
tropical moisture to shuttle into southwest California.

&&

.AVIATION...07/1157Z.

At 08Z at KLAX, there was no marine layer with a weak surface
inversion.

Moderate confidence for KSBA and north and low confidence
elsewhere including the desert TAFs. There is a 20-40 percent
chance of SHRA at times through at least 00Z for LA County TAFs,
highest KLAX/KSMO and KBUR to KLGB. There is a 5-10 percent chance
of a thunderstorm between 20Z-00Z.

50 percent chance that VLIFR cigs/vsbys continue for KWJF through
15Z-16Z. There is a 20 percent chance of brief IFR or lower
cigs/vsbys for KSMX through 16Z.

KLAX...Low confidence in TAF. VSBY may lower 3sm in SHRA. Any
east wind component should remain below 5 kts.

KBUR...Low confidence in the 00Z TAF. VSBY may lower to 2SM
during SHRA.

&&

.MARINE...07/646 AM.

For the waters south of the Channel Islands, there is a slight
chance of thunderstorms through this evening. Any thunderstorm
that storms could produce local gusty and erractic Gale Force
winds and seas, brief heavy downpours, and dangerous cloud-to-
surface lightning.

For the Outer Waters, below Small Craft Advisory (SCA) level
winds and seas are expected into Wednesday, except for local
advisory level gusts around Point Conception each afternoon and
evening. Wednesday evening into at least late next week SCA winds
are likely much of the time.

For the Inner Waters north of Point Sal, there is a 30% chance of
SCA level winds Wednesday afternoon/eve and a 60% chance for
Thursday. Increasing potential for SCA winds Friday into the
weekend.

For the Inner Waters south of Point Conception, localized pockets
of borderline SCA winds are likely Tuesday afternoon and evening.
Winds are likely to be a bit stronger and more widespread on
Wednesday with a 60% chance of advisories being issued. Focus
for SCA winds shifts towards the western portion of the Santa
Barbara Channel Thursday into the weekend.

Tropical moisture will continue to stream over the coastal waters
into Tuesday, bringing a slight chance of showers. Besides today
(mentioned above), a thunderstorm cannot be ruled out across the
outer waters on Tuesday.

A large south swell is impacting the area, causing increased
currents and surges in the vulnerable harbors. Breaking waves may
impact south harbor entrances, particularly for Ventura and Los
Angeles Counties (observed at Ventura Harbor).

&&

.BEACHES...07/642 AM.

There is a slight chance of thunderstorms across Ventura and Los
Angeles County beaches through this evening. Any thunderstorm that
storms could produce local gusty and erractic winds and seas,
brief heavy downpours, and dangerous cloud-to- surface lightning.

Significant coastal impacts are expected across Southern
California beaches through at least Tuesday. A large southeast to
south swell from Hurricane Marie has moved into 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 12 feet through today. Potentially life threatening rip
currents will continue as well. The highest surf is near Zuma and
Malibu Beach as well as Long Beach. 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.

Moderate coastal flooding has occurred and will continue around
high tides for south facing shores. 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 are expected to reach exceed 7 feet during the
evening high tide.

Expect significant beach erosion, flooded sandy beach areas, bike
paths, and parking lots, as well as low-lying roads. Of
particular concern will be the Alamitos Peninsula area in Long
Beach where coastal flooding will potentially cause local damage
to structures near time of high tide later today, Other areas of
concern the next couple of days include Catalina Island, 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...Heat Advisory in effect from 10 AM Wednesday to 8 PM PDT
      Thursday for zones 38-88-340>358-374-375. (See LAXNPWLOX).
     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).
     Heat Advisory in effect from 10 AM Tuesday to 8 PM PDT
      Thursday for zones 362-366>373-548. (See LAXNPWLOX).
PZ...NONE.

&&

$$

PUBLIC...Schoenfeld
AVIATION...Munroe
MARINE...Black/Lund
BEACHES...RS/Gomberg/KL
SYNOPSIS...Munroe/Schoenfeld

weather.gov/losangeles

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

NWS LOX Office Area Forecast Discussion