573
FXUS66 KLOX 082039
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
139 PM PDT Tue Sep 8 2026

.SYNOPSIS...08/231 AM.

A significant southerly swell will bring hazardous surf
conditions to the beaches through at least Tuesday. Isolated
showers will continue at times through Tuesday. The combination of
increasing heat and humidity across the area will cause moderate
to major impacts, focused over the coasts and valleys Tuesday
through at least Thursday.

&&

.SHORT TERM (TDY-FRI)...08/138 PM.

Overall, 12Z models in good synoptic agreement through the short
term period. At upper levels, high pressure will peak over the
area on Wednesday, then weaken Thursday/Friday. At the surface,
weak diurnal gradients will prevail tonight/Wednesday with
strengthen onshore gradients Thursday/Friday.

Forecast-wise, main concern in the short term period will be the
heat. With upper level high pressure peaking in strength and weak
offshore pressure gradients in the morning, Wednesday will be a
very hot day with highs ranging from the mid 80s to lower 90s at
the beaches to up to 108 degrees across interior sections. On
Thursday, the upper level high weakens and pressure gradients are
onshore all day, so temperatures will be several degrees cooler
(but still very warm). Overnight low temperatures through Thursday
night will only drop into the mid 60s to mid 70s. Unfortunately
with these temperatures, surface dew points are expected to be in
the mid 60s to mid 70s (thanks to Marie), making conditions VERY
oppressive. Based on Heat Risk grids (combining high/low
temperatures as well as humidity), there will be widespread MAJOR
HEAT RISK and localized pockets of EXTREME HEAT RISK Wednesday
through Thursday. Therefore, the HEAT ADVISORIES have been
upgraded to EXTREME HEAT WARNINGS for Wednesday through Thursday.
On Friday, highs are expected to cool at least 4-8 degrees for all
areas which should greatly limit any concerning heat risk across
the area.

Our secondary concern is continued shower/thunderstorm activity
moving across the area this afternoon. Showers and isolated
thunderstorms are expected to continue to move northward across
the area this afternoon with all areas having a chance of showers
and thunderstorms. There will be plenty of lightning, but rainfall
amounts (based on what has already fallen) are not expected to be
too significant at this time. So, hydrologic issues are expected
to be minimal. This activity will dissipate by early this evening.
On Wednesday, there will be enough lingering moisture/instability
over the Ventura/LA mountains to warrant a slight chance of
showers and thunderstorms Thursday afternoon across the higher
terrain.

Other than the heat and convective activity, the excitement levels
will remain low. With the weak offshore pressure gradients
Wednesday morning, there`ll be some offshore winds. However, upper
support is minimal and any offshore winds are expected to remain
well below advisory levels. However, I would not be surprised to
see some locally gusty conditions across the Santa Lucia Range
Wednesday morning.

.LONG TERM (SAT-TUE)...08/138 PM.

For the extended, 12Z models continue to exhibit good synoptic
agreement through the extended period. At upper levels, the ridge
will remain flat through Monday, then may start to strengthen a
bit on Tuesday. At the surface, weak to moderate onshore pressure
gradients are expected.

Forecast-wise, the above pattern will result in rather benign
weather through the period. Skies should remain mostly clear for
most areas with some stratus/fog likely returning to the coastal
plain during the night/morning hours. As for temperatures, there
will be minor day-to-day fluctuations in temperatures, but the
area will be about 3-6 degrees below normal. With atmospheric
moisture also decreasing, conditions will be rather comfortable
and no heat issues are expected.

&&

.AVIATION...08/1729Z.

At 1641Z at KLAX, there was no marine layer. A surface inversion
had a top near 1500 feet, with a temperature of 28 degrees C.

There is a slight chance of showers and thunderstorms continuing
through 00Z for all sites, but there is currently a cluster of
storms in LA County as well as west of the coast, heading into
LA/Ventura Counties.

Low to moderate confidence in the Central Coast sites. There is a
40 percent chance of no low clouds at KSMX and a 40 percent chance
of LIFR conds at KSBP 06Z-17Z.

Good confidence in no low clouds for the rest of the sites.

KLAX...Good confidence in TAF. -TSRA will impact the terminal
through around 19Z-20Z, with a slight chance through 00Z. Any
showers could produce locally gusty winds and brief moderate to
heavy rain. No significant east wind component expected, although
significant wind shifts may occur with any TS.

KBUR...Good confidence in TAF. Showers are likely to pass over the
area through the afternoon. There is a 30 percent chance of
-TSRA through 20Z, with a slight chance through 00Z. Any showers
 could produce locally gusty winds and brief moderate to heavy
 rain. Significant wind shifts may occur with any TS.

&&

.MARINE...08/128 PM.

There continues to be a slight chance of thunderstorms over
the waters through this evening, with a cluster of storms
currently moving to the northeast through large portions of the
waters south of Point Sal. Smaller yet nonzero chances exist
Wednesday.

Good confidence in winds and seas increasing to Small Craft
Advisory (SCA) levels this afternoon focused south and west of
Point Sal, with moderate confidence in winds increasing across all
Outer Waters by Wednesday at the earliest. Winds and at times seas
will likely exceed SCA levels into early next week.

Across the nearshore waters along the Central Coast, winds will
locally reach SCA levels today and tomorrow, with more expansive
gusty winds Thursday into early next week, with SCAs likely to be
issued.

South of Point Conception, moderate confidence in SCA winds across
the western half of the Santa Barbara Channel (locally eastern
portions) each afternoon and evening into early next week. Thus,
there is a 40-60% chance for SCAs to be issued each day, with
highest chances today and again this weekend. Local SCA gusts will
be possible each afternoon-evening across the Santa Monica Bay and
San Pedro Channel into early next week with highest chances
today.

The southerly swell that has impacted the coastal waters over the
last few days will continue to gradually subside through tonight
and tomorrow.

&&

.BEACHES...08/123 PM.

There is a slight chance of thunderstorms across all beaches into
this evening. Any thunderstorm that forms could produce local
gusty and erratic winds, brief heavy downpours, and dangerous
cloud-to-ground lightning. Low but nonzero thunderstorm chances
exist Wednesday.

A south swell from post tropical cyclone Marie is subsiding, but
continued coastal impacts are likely through at least tonight.
High surf will continue through tonight, gradually decreasing as
the southerly swell decreases. Highest surf is still expected
across south facing coasts across LA/Ventura Counties, esepcailly
near Zuma Beach and the Long Beach coastline. Very strong and
dangerous rip currents will continue as well.

Moderate coastal flooding has occurred and minor to locally
moderate coastal flooding will continue through Thursday around
evening high tides for south facing shores as the swell
decreases, but tides remain very high. The actual observed tides
have been running about 6 inches above predictions, with the
evening tides near or exceeding 7 feet.

Expect continued beach erosion, flooded sandy beach areas, bike
paths, and parking lots, as well as low-lying roads. Some areas
that may continue to see impacts are: the Alamitos Peninsula in
Long Beach, Avalon on Catalina Island, and Oxnard to Malibu
(including the Pacific Coast Highway near Point Mugu).

Beach Hazards Statements (BHS) have been issued for the beaches
of Los Angeles and Ventura Counties following the expiration of
the Coastal Flood Advisories due to the very high evening tides
Wednesday and Thursday. There will be some lingering southerly
swell into Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Warning in effect from 8 AM Wednesday to 8 PM
      PDT Thursday for zones 38-87-88-340>358-362-366>375-548. (See LAXNPWLOX).
     Coastal Flood Advisory in effect until 11 PM PDT this evening
      for zones 87-354-362-366. (See LAXCFWLOX).
     High Surf Advisory in effect until 11 PM PDT this evening for
      zones 87-354-362-366. (See LAXCFWLOX).
     Beach Hazards Statement in effect from 11 PM PDT this evening
      through Thursday evening for zones 87-354-362-366. (See LAXCFWLOX).
     Beach Hazards Statement in effect until 11 PM PDT this
      evening for zones 340-346. (See LAXCFWLOX).
     Beach Hazards Statement in effect through Thursday evening
      for zones 349-350. (See LAXCFWLOX).
     Heat Advisory in effect until 8 AM PDT Wednesday for zones
      362-366>373-548. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson
AVIATION...Lewis
MARINE...Lewis
BEACHES...Lewis
SYNOPSIS...Munroe/Schoenfeld/Ciliberti

weather.gov/losangeles

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