709
FXUS66 KLOX 170047
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
547 PM PDT Fri May 16 2025

.SYNOPSIS...16/125 PM.

Strong onshore flow and a deep marine layer will bring cool
weather through Saturday. Gusty onshore winds are expected in the
Antelope Valley during the afternoon and evening. Night through
morning drizzle or light rain is possible Saturday. A warming
trend will be will begin Sunday and continue through next week as
high pressure develops. Temperatures more typical of the summer
season are likely away from the coast for the latter half of next
week.

&&

.SHORT TERM (FRI-MON)...16/159 PM.

An approaching upper level trough is increasing onshore flow and
cooling the air mass as well. Highs today cooled 3-6 degrees
across most of the area with the exception of interior SLO County,
the higher mountains, and the Antelope valley where temperatures
warmed by 2-4 degrees.

The trough will continue to deepen across California resulting in
a higher marine layer tonight, likely up to around 4000 feet, and
possibly even some patchy drizzle or very light rain, especially
near the south facing coastal slopes. Clearing will slower
Saturday and some coast and valley areas may remain cloudy much of
the day. There`s also a chance of a reverse clearing pattern which
would result in more clearing near the coast than inland areas.
Temperatures will likely stay in the 60s in most areas, which
would be 5-15 degrees below normal. Gusty southwest winds are
expected across the Antelope Valley in the afternoon and evening and
gusty north to northwest winds are expected across southwest
Santa Barbara County.

The trough is expected to shift east into the Rockies Sunday as a
high pressure ridge over the eastern Pacific moves closer to the
coast. A moderate offshore gradient trend will develop leading to
5-10 degrees of warming most areas with either minimal or earlier
clearing marine layer. Another round of gusty Sundowner winds
expected across southern Santa Barbara County is expected later
Sunday afternoon and evening, and this time including eastern
Santa Ynez as winds aloft start veer to the north and even
slightly northeast.

The warming trend will continue Monday with some additional
offshore trends leading to some morning northeast winds across the
hills and mountains and possibly some of the valleys as well.
Expecting widespread warming trends of 5-10 degrees over Sunday
and some valley areas as much as 15 degrees warmer, getting close
to 90 degrees, including interior SLO County and the western San
Fernando Valley.

.LONG TERM (TUE-FRI)...16/225 PM.

Next week is going to be a hot one and lasting at least two days
longer than the previous heat wave. Highs are expecting to be
fairly similar to the last heat wave, topping out in the low 100s
in the warmer valleys Tuesday through, low 90s in Downtown LA,
and 80s across most other areas except the beaches. There may
still be a lingering shallow marine layer Monday morning across
coastal LA County resulting in some dense fog but that should
clear fairly quickly. If the forecast remains on track, and right
now confidence is high, another round of heat advisories will be
needed for the coastal valleys and possibly even parts of the
interior coastal plain.

Onshore flow will start to return Thursday that will begin a slow
cooling trend into next weekend.

&&

.AVIATION...17/0046Z.

At 00Z at KLAX, the marine inversion was around 15 feet deep. The
top of the inversion was 2300 feet with a temperature of 17
degrees Celsius.

High confidence in TAFs for KWJF and KPMD.

Moderate confidence in TAFs for remaining sites where flight
category changes may be off by 2 hours and 1 category. There is a
30-50 percent chance of only brief to no return to VFR at coastal
sites from SBA and south including KLAX.

KLAX...Moderate confidence in TAF. There is a 20-30% chance for
an east wind component of 8 kts between 10Z and 18Z. Best chances
between 13Z and 17Z.

KBUR...Moderate confidence in TAF. Return of cigs may be off +/- 2
hours, and there is a 20% chance for cigs 007-009.

&&

.MARINE...16/156 PM.

For the Outer Waters through Tuesday, high confidence in
combination of Small Craft Advisory (SCA) level winds and seas.
For Saturday afternoon through Sunday night, there is a 60-70%
chance of Gale force winds. Gales look to be strongest and most
widespread Sunday afternoon through late Sunday night. There may
be a lull in the winds Sunday morning. Seas will reach 12-14 feet.
Rough, short period seas will exist into at least Monday.

For the Inner Waters through Sunday night, high confidence in SCA
level winds, especially in the afternoon and evening hours. There
is a 50-60% chance of Gale force winds Saturday afternoon through
Sunday evening, with a lull in the winds likely late Saturday
through Sunday morning. Another Gale Warning is likely for Sunday
afternoon and evening. For Monday through Tuesday, there is a
50-70% chance of SCA level winds continuing. Seas will reach 10-12
feet. Rough, short period seas will exist into Monday.

For the Inner Waters south of Point Conception through Saturday
morning, high confidence in winds and seas remaining below SCA
levels. For Saturday afternoon through Sunday night, high
confidence in SCA level winds focused mostly through the Santa
Barbara and western sections of the southern Inner Waters.
Additionally, there is a 50% chance of Gale force winds across the
Santa Barbara Channel Saturday evening through Saturday night.
There will be a relative lull in the winds overnight, then another
Gale Warning is likely (50-60% chance) for the Santa Barbara
Channel Sunday afternoon into late night. Seas may approach 8
feet with short periods due to the wind. For Monday through
Tuesday, moderate confidence in winds and seas remaining below SCA
levels.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 10 AM to 9 PM PDT Saturday for
      zones 381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM Saturday to 3 AM PDT Sunday
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from noon to 6 PM PDT Saturday
      for zone 650. (See LAXMWWLOX).
     Gale Warning in effect from 6 PM Saturday to 3 AM PDT Sunday
      for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 6 PM Saturday to 3 AM PDT
      Sunday for zone 655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT Saturday for
      zones 670-673-676. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM Saturday to 3 AM PDT Monday
      for zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Munroe
MARINE...Lewis
SYNOPSIS...MW/Hall

weather.gov/losangeles

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