920
FXUS66 KLOX 270325
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
825 PM PDT Sat Sep 26 2026

.SYNOPSIS...26/758 PM.

Substantial cooling is expected across the area Sunday and
Monday. Beach impacts from Tropical Cyclones well south of the
region are expected to peak Monday and Tuesday in the form of high
surf, beach erosion, and possible coastal flooding. A significant
warming trend is expected Tuesday and Wednesday.

&&

.SHORT TERM (SAT-TUE)...26/733 PM.

***UPDATE***

High clouds are have reached southern California, which will
likely disrupt marine cloud formation, especially south of Point
Conception. Lower confidence on marine layer clouds and patchy fog
for the coasts, but somewhat higher confidence in clouds for the
Central Coast. Despite the high clouds, we could still see some
brief marine layer clouds and patchy fog form during the early
morning hours for coastal Ventura County and southward.

Guidance appears to be trending toward a drier solution for
Sunday and Monday, as this upper level low passing through appears
to be moisture starved. Any showers (10-15% chance) that form
should carry little to no impacts. However, additional clouds and
colder temperatures will translate to 5 to 10 degrees of cooling
Sunday/Monday. Weak northerly offshore winds start to develop
early Monday, with some borderline advisory level Sundowner winds
by Monday evening. Offshore gradients peak around 3.0 mb Tuesday
morning, and still appear to favor a fairly northerly direction.
This supports a 6 to 15 degree boost in Tuesday`s high
temperatures.

***From Previous Discussion***

An upper level trough is expected to dig southward over the area
Sunday into Tuesday. This feature will steer Hurricane Polo into
Baja California Sur and keep most of the moisture south and east
of our CWA. There is still a handful of ECWMF ensemble guidance
that brings enough moisture to produce some light showers over LA
county, so have left 15% POPs in despite the downward trend. This
trend is due to a better handling of the trough and its timing.
There also could be a few light showers across the far interior
solely due to trough dynamics, but most likely will just remain
dry. Onshore pressure gradients will respond to the height falls
with NAM/ECWMF values around +4mb. This will result in gustier
winds across the interior strongest over LA county. Not expecting
any advisories but wouldn`t be surprised to see some local gusts
to 45 mph Sunday afternoon/eve over eastern San Gabriels. There is
a moderate chance for low-end advisory Sundowners on Monday.

The biggest concern in the short-term is the southerly swells
produced by Hurricane Odalys and Polo. Especially considering
that the LA/VTA coastline has enhanced vulnerability due to
Hurricane Marie over Labor Day. Most hazardous conditions are
expected Monday and Tuesday when high tides overlap with the
continuing southerly swells. Please read the beaches/marine
sections of the AFD for more information. For even more details,
refer to CFWLOX.

With the cooling trend, temperatures should be a bit below normal
by Monday (especially across far interior). Near normal close to
the coast. Trough will exit east with ridging building in from the
west which will result in a flip into offshore flow and warming
temperatures.

.LONG TERM (WED-SAT)...26/100 PM.

Guidance is generally in agreement mid next week for building
ridging over the area and likely some offshore flow. There is
quite the uncertainty in the evolution of the ridge & exactly
how much offshore flow will occur. Although decent confidence
that is will be warm with about a 30-40 percent chance of near
100 degree temperatures in the valleys and similar chances for
Downtown LA and San Luis Obispo reaching 90 or higher.

National Hurricane Center is tracking a developing disturbance
south of the Gulf of Tehuantepec. Current projections indicate
that this system will likely strenghten significantly. If this
does occur, the upper-level ridging would steer this system west-
northwest for quite some time putting it in a favorable position
for southerly swell impacts for the beaches. We will have to keep
an eye on this system because there is a chance it produces a
building southerly swell which could result in impacts at the
beaches. However, this is rather far out and would not see impacts
until probably after October 4th.

&&

.AVIATION...27/0124Z.

At 2154Z at KLAX, there was no marine layer. There was a surface
based inversion with a top at 1500 feet with a temperature of 27
Celsius.

High confidence in VFR TAFs for KPRB, KBUR, KVNY, KWJF, and KPMD.

Low confidence in flight cats tonight for remaining TAFs. Chance
for no low clouds tonight at KSBP (50%) and KSMX (30%). There is a
20-40% chance for IFR-MVFR cigs tonight at remaining sites,
highest for KLAX/KLGB/KSMO, highest chances from 13-15Z. South of
Point Conception cigs would likely be patchy and may frequently
bounce between SCT and BKN if they form.

KLAX...High confidence in TAF through 06Z, then low confidence in
flight cat thereafter. 40% chance for BKN007-012 conds 10Z-17Z.
If cigs form they may bounce between BKN and SCT frequently.

Moderate to high confidence in TAF through 18Z Sat and
after 03Z Sun, otherwise high confidence. CIGs may scatter and
reform several times due to high level clouds this morning. There
is a 30% chance of BKN008-012 CIGs after 03Z Sun. High confidence
in no significant east win component.

KBUR...High confidence in VFR TAF.

&&

.MARINE...26/817 PM.

Through this weekend, high confidence in Small Craft Advisory
(SCA) winds and steep seas affecting the outer waters. The current
SCAs have been extended through Tuesday night. Gale force gusts
will be possible at times, especially Monday afternoon and evening
across the far southern waters (PZZ676). Nearshore along the
Central coast will see SCA winds and steep seas again Sunday and
Monday in the afternoon and evening, and likely again on Tuesday.

For the nearshore waters south of Point Conception, there will be
a chance of SCA winds over the western Santa Barbara Channel
Sunday and especially Monday during the afternoon and evening, and
likely again on Tuesday.

Southerly swells from Hurricanes Odalys (SSW) and Polo (SSE) will
affect the region this weekend through Tuesday. These swells will
create larger waves and surf nearshore, which could impact some
harbor entrances, especially Sunday through Tuesday. For the
waters off the LA Coast, SCA winds are likely Monday afternoon and
evening over the western portion.

&&

.BEACHES...26/823 PM.

Southerly swells from Tropical Cyclones Odalys and Polo will
affect the waters through the middle of next week, with Hurricane
Polo likely sending the more impactful swell from the SSE,
affecting our coastline Monday and Tuesday. This swell timing
will line up with very high tides Monday and Tuesday in the late
morning hours. Lastly, some south-facing shores are more
vulnerable because of the lingering erosion effects from Hurricane
Marie earlier this month.

Surf heights across Los Angeles and Ventura Counties are likely to
peak around 4-7 foot Monday and Tuesday, while the Santa Barbara
south coast should see surf in the 3-5 foot range. High tides
will steadily build each day and peak Monday and Tuesday, likely
reaching around 7 feet (MLLW) in the late morning hours - which is
higher by almost a foot over astronomical tides due to ongoing
effects of El Nino.

While this swell is slightly smaller than the swell from Marie,
there is a significant concern of Coastal Flooding over vulnerable
south-facing beaches. The areas of most concern include Avalon,
Long Beach, Malibu and Santa Barbara. The reasonable worst-case
scenario is for impacts similar to those from Hurricane Marie, but
the most likely outcome is for impacts to be a step less. The one
exception being Avalon on Catalina Island, as the swells from
Hurricane Polo will be more from a southeasterly direction than
with Marie, which they are more exposed to. The same goes for
Santa Barbara Harbor where the risk is less but still present.

South-facing beaches should plan for shallow flooding of seawater
over low lying beach walkways, parking lots, and roads as well as
potential for significant beach erosion. Very localized damage to
structures is also possible in the most vulnerable areas.

Beach Hazards Statements are in effect for LA, Ventura, and the
Santa Barbara south coast. Then a Coastal Flood Advisory and High
Surf Advisory are in effect for LA and Ventura Monday and Tuesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through late Sunday night
      for zones 87-354-362-366. (See LAXCFWLOX).
     Coastal Flood Advisory in effect from 5 AM Monday to 5 PM PDT
      Tuesday for zones 87-354-362-366. (See LAXCFWLOX).
     High Surf Advisory in effect from 5 AM Monday to 5 PM PDT
      Tuesday for zones 87-354-362-366. (See LAXCFWLOX).
     Beach Hazards Statement in effect through Wednesday afternoon
      for zones 349-350. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect from 3 PM Sunday to 3 AM PDT
      Monday for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Phillips/DB
AVIATION...Phillips/Lewis
MARINE...Lewis/Ciliberti
BEACHES...Lewis/Ciliberti
SYNOPSIS...DB/CILIBERTI

weather.gov/losangeles

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