673
FXUS66 KLOX 282122
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
222 PM PDT Mon Sep 28 2026

.SYNOPSIS...28/123 PM.

Beach impacts from Tropical Cyclones well south of the region are
expected through Tuesday in the form of high surf, beach erosion,
and possible coastal flooding. Warming temperatures are expected
Tuesday with periods of northeast winds in the mountains. A major
heat wave is likely this weekend into next week with dangerously
hot temperatures and periods of Santa Ana winds.

&&

.SHORT TERM (TDY-THU)...28/202 PM.

An upper low continues to move through the state today and
expected to be into AZ by Wednesday. As the low progresses
through the area, northerly winds will increase across the Santa
Barbara and Ventura County mountains as well as the I5 corridor
region with gusts to around 45 mph tonight into Tuesday morning.

On Tuesday increasing surface pressures over the Great Basin
following the upper low will usher in the first little Santa Ana
of the season. This will be a low end Santa Ana with northeast
winds mostly confined to the mountains and mostly below 35 mph.
But the shift to northeast winds aloft will cause humidities to
drop considerably across the mountains and should even be
noticeable at lower elevations. Temperatures will rocket up at
least 5 degrees at the coast and as much as 10 or more degrees
elsewhere.

A slight cool down is expected Wednesday and Thursday as
gradients turn back to lightly onshore. It will still be 2-5
degrees above normal but with the return to onshore flow it`s
likely humidities, especially closer to the coast, will increase
by 15-30 percent.

.LONG TERM (FRI-MON)...28/222 PM.

Most of the models now are in agreement with a potentially
dangerous heat wave this weekend and all of next week due to high
pressure aloft and increasing offshore gradients. Warming will
begin to ramp up Friday with around 3 degrees of warming each day
through next Monday. Gradients will be a factor, though even
without the offshore gradients forecast by the models this would
still be an impressive heat wave. But if the medium or high end
gradient solutions pan out this could be a very dangerous and week
long heat wave with warmer valley highs of 105-110, Downtown LA
and other inland coastal zones 100-104, and coastal areas 85-98.
PW`s are expected to remain under an inch through next week, but
due to the continued much above normal SST`s, humidities at lower
elevations will remain much higher than we are used to.

&&

.AVIATION...28/2008Z.

At 20Z at KLAX, there was no marine layer or inversion.

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

Fairly high confidence elsewhere with a 10-20 of brief IFR or
lower cigs/vsbys focused between

KLAX...Fair confidence in TAF. There is a 10 percent chance
BKN008 conds 08Z-16Z. High confidence in no significant east wind
component.

KBUR...High confidence in VFR TAF.

&&

.MARINE...28/1258 PM.

High confidence in Small Craft Advisory (SCA) winds and steep
seas affecting the outer waters through late least Tuesday night.
Local Gale Force gusts will be possible at times, especially
this afternoon and evening across the outer waters south of Point
Conception. There is a 10-20% chance for Gale Warning conditions
during that time period. 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 are
expected across the entirety of the Santa Barbara Channel and
portions of the inner waters adjacent to Los Angeles and Orange
Counties on today, 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
south exposed harbor entrances.

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

&&

.BEACHES...28/103 PM.

Southerly swells from Tropical Storm Odalys and Hurricane Polo
will affect the waters through the middle of this coming week,
with Hurricane Polo likely sending the more impactful swell from
the SSE (160-170 degrees) affecting our coastline Monday and
Tuesday. This swell timing will line up with very high tides
Monday and Tuesday in the late morning hours. 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
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 still significant concern of Coastal Flooding over
vulnerable south-facing beaches. The areas of most concern include
Avalon, Long Beach, Malibu, and to a lesser extent 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 possible in the most vulnerable areas. Minor tidal
overflow may affect west facing beaches due to very high tides.

Beach Hazards Statements (BHS) are in effect for Santa Barbara
south coast through Wednesday. Then a Coastal Flood Advisory and
High Surf Advisory are in effect for LA and Ventura through
Tuesday afternoon. 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.

Active East Pacific Hurricane Season looks to continue with
additional southerly swells and surf/coastal flooding impacts
possible into next week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory in effect until 5 PM PDT Tuesday for
      zones 87-354-362-366. (See LAXCFWLOX).
     High Surf Advisory in effect until 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).
     Wind Advisory in effect from 6 PM this evening to 6 AM PDT
      Tuesday for zones 349>353-376>378. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 11 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until midnight PDT tonight for
      zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Munroe
MARINE...RM/Lewis/Black
BEACHES...RM/Lewis/Ciliberti
SYNOPSIS...MW

weather.gov/losangeles

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