631
FXUS66 KLOX 271533
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
833 AM PDT Sun Sep 27 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 (TDY-TUE)...27/300 AM.

High clouds are slowly shifting to the south and will make their
way mostly out of LA County by the afternoon. Currently, these
high clouds are disrupting the formation of marine layer clouds
for areas south of Point Conception, and any low clouds and patchy
fog that forms will be pretty short-lived. North of Point
Conception, low clouds and patchy fog are overspreading the
Central Coast, and even into the Southern Salinas Valley. These
low clouds are expected to burn off by the afternoon. Low clouds
and fog are forecast to return to the Central Coast and possibly
across the LA Coast tonight into Monday morning.

Guidance appears to be trending toward a drier solution for
today and Monday, as this upper level low passing through appears
to be moisture starved. Any showers (10 to 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.

.LONG TERM (WED-SAT)...27/305 AM.

Good confidence in high pressure and warmer temperatures Wednesday
through the rest of the week. Current guidance has northerly
onshore flow peaking Tuesday, then trending weaker each day.
Offshore gradients look moderate at best, so coastal areas will
likely begin to see some decent sea breezes by Wednesday. However,
we could still see valley temperatures nearing 100 degrees later
this coming week.

National Hurricane Center is tracking a developing disturbance
south of the Gulf of Tehuantepec. Current projections indicate
that this system will likely strengthen 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...27/1312Z.

At 1237Z at KLAX, the marine layer was 1000 ft deep. The top of
the inversion was at 1900 feet with a temperature of 24 Celsius.

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

Moderate to high confidence in KPRB, KSMX, and KSBP. Timing of
flight cat changes may be off by +/- 2 hours. There is a 30%
chance of IFR conds at KPRB after 06Z Mon. There is a 20% chance
of VFR conds Sunday night for KSBP and KSMX.

Low confidence in flight cats for remaining TAFs. There is a
20-40% chance for IFR-MVFR cigs through 16Z, and may scatter and
reform briefly due to upper level clouds disrupting the marine
layer. There is a 30% chance of IFR-MVFR cigs at KLAX, KLGB, and
KSMO after 06Z Mon.

KLAX...Low confidence in TAF through 17Z Sun and after 06Z Mon,
otherwise high confidence. 30% chance for BKN007-012 conds
through 17Z. If cigs form they may bounce between BKN and SCT
frequently. There is a 30% chance of BKN008-015 conds after 06Z
Mon. High confidence in no significant east wind component.

KBUR...High confidence in VFR TAF.

&&

.MARINE...27/820 AM.

High confidence in Small Craft Advisory (SCA) winds and steep
seas affecting the outer waters through at least Tuesday night.
Gale force gusts will be possible at times, especially Monday
afternoon and evening across the outer waters south of Point
Conception. Nearshore along the Central coast will see SCA winds
and steep seas each afternoon and evening through Tuesday.

For the nearshore waters south of Point Conception, SCA winds may
occur across western portions of the Santa Barbara Channel today,
likely expanding across the entirety of the Santa Barbara Channel
and portions of the inner waters adjacent to Los Angeles and
Orange Counties on Monday, with moderate chances Tuesday.

Southerly swells from Hurricanes Odalys (SSW) and Polo (SSE) will
continue to affect the region through Tuesday. These swells will
create larger waves and surf nearshore, which could impact some
harbor entrances.

Conditions are likely to improve to below SCA levels Wednesday
into next weekend, except for occasional northwest SCA winds near
Point Concpetion in the afternoon/evening hours.

&&

.BEACHES...27/830 AM.

Southerly swells from Tropical Cyclones Odalys and Polo will
affect the waters through the middle of this week, with Hurricane
Polo likely sending the more impactful swell from the SSE,
affecting our coastline Monday and Tuesday. This swell timing will
likely 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 feet Monday and Tuesday, while the Santa Barbara
south coast should see surf in the 3-5 foot range. High tides will
steadily build 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. Minor
tidal overflow is possible for west facing beaches due to the very
high tides.

Beach Hazards Statements (BHS) are in effect for LA and Ventura
coasts through early Monday morning, and for the Santa Barbara
south coast into Wednesday. Then a Coastal Flood Advisory and
High Surf Advisory are in effect for LA and Ventura Monday and
Tuesday. A BHS may need to be issued for the LA and Ventura coasts
for Tuesday afternoon through Wednesday (lining up with Santa
Barbara) due to the very high tides.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through late tonight 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 this afternoon to 3
      AM PDT Monday for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from noon Monday to midnight
      PDT Monday night for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

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

weather.gov/losangeles

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