-- Discussion containing changed information from previous version are highlighted. --
315
FXUS66 KLOX 252322
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
422 PM PDT Sat May 25 2024

.SYNOPSIS...25/200 PM.

The May gray pattern will continue through next Saturday. Varying
amounts of night and morning low clouds and fog are expected
for the coast and valleys during the period. Otherwise mostly
clear skies will prevail. Temperatures are forecast to be a few
degrees below normal into early next week then warm to near normal
to a few degrees above normal for mid to late next week.

&&

.SHORT TERM (TDY-TUE)...25/153 PM.

Marine layer clouds from this morning mostly cleared SLO/SBA
Counties except for the eastern Santa Ynez Mtns and adjacent
coast early this afternoon, while the low clouds over the
VTU/L.A. County coast, vlys and coastal slopes changed to broken
stratocu especially away from the coast. The stratocu over these
areas will probably persist thru mid afternoon but should scatter
out before sunset this evening. Otherwise and elsewhere, mostly
sunny skies should prevail for the rest of the day.

Gusty NW winds will persist over SW SBA County thru this
afternoon, with gusty W-NW winds for the Antelope Vly into the
foothills and I- 5 Corridor. Winds are expected to be mostly sub-
Advisory thru this afternoon. Elsewhere, breezy to gusty SW-NW
winds can be expected thru this afternoon.

Temps this afternoon should be slightly warmer than yesterday but
remain significantly below normal by as much as 6-12 degrees.
Highs should reach the upper 60s to low 70s for the inland coast,
vlys and lower mtns.

A broad NW flow aloft with H5 heights increasing to about 576-577
dam this afternoon will turn more WSW thru Sun with H5 heights
rising to 579-580 dam by Sun afternoon. Little change can be
expected thru Mon night then flat upper ridging should move in
with H5 heights expected to be around 584 dam by Tue afternoon.

The marine layer May gray pattern will continue thru Tue across
SW CA. The marine inversion is forecast to be around 3000-3500 ft
tonight then slowly lower to around 1500 ft Sun night and to about
1200-1400 ft or so Mon night. Low clouds and some fog should
affect much of the coast and adjacent vlys tonight into Sun
morning and up to some of the lower cstl slopes. Night and
morning low clouds and fog should persist Mon thru Tue as well,
with the low clouds not having as much inland penetration as the
marine inversion lowers. The low clouds should clear to or off the
coast for the most part each afternoon, with Santa Catalina
Island probably having some low clouds linger thru much of the
day.

Sundowner winds at mostly sub-Advisory levels should affect the
western portions of the S SBA County coast and mtns each evening
thru Tue. Otherwise, strong onshore gradients will bring breezy to
gusty onshore flow to many areas, strongest afternoon and evening
hours. Winds could approach Advisory levels at times in the
Antelope Vly and foothills.

Temps will have a warming trend Sun and Mon then should change
little for Tue. Even so, it should remain several degrees below
normal during the period, except increasing to a few degrees above
normal for the interior areas including some of the mtns and into
the Antelope Vly for Mon and Tue. Highs for much of the inland
coast, vlys and lower mtns should be in the upper 60s and 70s Sun,
and in the 70s to lower 80s Mon and Tue. The warmest areas should
be in the Antelope vly, with highs in the upper 80s to around 90
by Mon.

.LONG TERM (WED-SAT)...25/155 PM.

Not a whole lot of change can be expected in the extended period.
It looks like very weak upper troffiness with H5 heights around
584 dam will prevail Wed and Thu, then slightly stronger upper
level troffiness will persist Fri and Sat with H5 heights around
581-582 dam.

Good onshore pressure gradients to the N and E will help to keep
the marine layer pattern over the forecast area Wed thru Sat.
Varying amounts of night and morning low clouds and fog are
expected for the coast and vlys, moving farthest inland Fri and
Sat as the marine inversion deepens. Otherwise, mostly clear skies
can be expected.

Just subtle changes in temps can be expected each day, with
reading expected to be a few degrees below normal for the coast
and some vlys and a few degrees above normal elsewhere over inland
areas. Afternoon highs for the inland coast, vlys and lower mtns
should be in the 70s to mid 80s, while the Antelope Vly heats up
into the upper 80s to lower 90s each day.

Seasonably breezy onshore to northwest winds will likely continue
each afternoon to evening with interior areas prone to west to
northwest winds as well as southwest Santa Barbara County
potentially reaching close to Advisory levels at times.

&&

.AVIATION...
-- Changed Discussion --
25/2321Z.

At 2215Z at KLAX, the marine layer was 3100 ft deep. The top of
the inversion was at 6600 feet with a temperature of 12 C.

For 00Z TAF package, high confidence in desert TAFs and low to
moderate confidence in coastal/valley TAFs. Lower confidence for
coastal/valley sites due to uncertainties in the behavior of the
marine layer stratus. Timing of flight category changes could be
off by +/- 4 hours and CIGs will range from IFR/MVFR levels north
of Point Conception and MVFR levels south of Point Conception.

KLAX...Low to moderate confidence in 00Z TAF. Timing of return of
MVFR CIGs could be +/- 4 hours of current 06Z forecast. Timing of
dissipation of MVFR could be +/- 2 hours of current 18Z forecast.
No significant easterly wind component is expected.

KBUR...Low to moderate confidence in 00Z TAF. Timing of return of
MVFR CIGs could be +/- 3 hours of current 09Z forecast. Timing of
dissipation of MVFR could be +/- 2 hours of current 18Z forecast.
-- End Changed Discussion --

&&

.MARINE...25/206 PM.

Moderate to high confidence in forecast.

Across the outer waters, Small Craft Advisory (SCA) level winds
are expected to continue through this weekend and much of next
week. Winds may drop below advisory levels during the morning and
early afternoon hours through Monday. Then Tuesday through
Thursday SCA conditions are expected to be fairly constant. There
is a 30-40% chance of Gale Force winds Tuesday night through
Wednesday night. As for seas, starting Tuesday morning seas will
build to SCA levels and becoming steep and choppy through at least
Thursday night.

Across the nearshore waters along the Central Coast, SCA winds
will push into the western portion of the waters this afternoon
and evening. Then, there is a 30-40% chance of SCA winds during
the afternoon and evening hours Sunday and Monday. Tuesday
afternoon through Wednesday, SCA level winds and seas are likely
(60-70%), with a 20-30% chance of Gale Force winds.

Across the southern inner waters, there is a 70-80% chance of SCA
level winds across the the Santa Barbara Channel (strongest in the
western portion) this afternoon and evening. There is a 30-40%
chance of SCA level winds across the western portion of the
Channel each afternoon and evening through Tuesday, followed by a
50% chance on Wednesday. South of the Channel Islands, there is a
30% chance of SCA level winds pushing into the western portion of
the southern inner waters tonight with choppy SCA seas.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for
      zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Sirard
AVIATION...RAT
MARINE...Lund/Schoenfeld
SYNOPSIS...Sirard

weather.gov/losangeles

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