201
FXUS66 KLOX 030259
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
759 PM PDT Sun Jun 2 2024

.SYNOPSIS...02/757 PM.

A warming trend will establish through Wednesday due to high
pressure aloft building in and weakening onshore flow. The warming
trend will be most pronounced away the coast. Closer to the
coast, night through morning low clouds and fog will persist with
continued moderate to strong onshore flow.

&&

.SHORT TERM (SUN-WED)...02/758 PM.

Current satellite imagery showing low clouds lingering this
evening across parts of Ventura county and the Central Coast.
The marine layer is still deep over the LA basin, with ACARS
data showing a depth around 3000 feet. In addition, onshore
pressure gradients remain strong with LAX-DAG gradient once
again peaking over +9 mb this afternoon. As a result, low clouds
expected to fill in across most coastal/valley areas tonight
into Monday morning, with some patchy drizzle possible. The
strong onshore gradients causing widespread wind gusts of
25 to 35 mph across the interior this afternoon/evening, with
local gusts over 40 mph in the Antelope Valley and adjacent
foothills. Northwest winds are expected to ramp up a bit
this evening across southwest Santa Barbara county, but
mostly expected to remain below advisory levels. High resolution
models are ramping up northwest winds on Monday into Monday night,
in terms of areal coverage and wind speed. As a result, have
posted a wind advisory for Monday into Monday night for the I-5
corridor, western Antelope Valley foothills, and southwest Santa
Barbara county where wind gusts of 40 to 50 mph are expected.
Earlier forecast on warming trend looks on track.

*** From previous discussion ***

High confidence in a warming trend focused across Coastal Valleys
to interior through Tuesday or Wednesday as a modest ridge of
high pressure builds into the region. The marine layer should
somewhat shelter coastal areas from the warming influence of the
ridge. It will also continue to provide night to morning low
clouds. The pattern continues to look favorable for patchy
drizzle, especially Monday night into early Tuesday. Low
confidence in the extent of the marine layer especially into
Tuesday due to competing forces between the building ridge
pressing down on the marine layer and the potential for a Catalina
Eddy acting to prop it up. This leaves us with only moderate
confidence in daytime highs across coastal valleys in particular.
Daytime highs will likely warm 10-15 degrees between today and
Tuesday or Wednesday, except closer to 5 degrees along the coast
and perhaps into lower elevation coastal valleys. By Tuesday this
will likely result in highs generally in the 70s near the coast,
80s to near 90 for coastal valleys, and 90s to near 100 further
inland.

Continued northwest flow across the region will support gusty
winds at times focused southwest Santa Barbara and the I-5
corridor in the mountains east to the Antelope Valley. A trough
passing to the north late Monday may (30-50 percent chance) boost
winds into advisory territory.

.LONG TERM (THU-SUN)...02/115 PM.

The peak of the heat will likely be Wednesday for many areas,
although some coastal and coastal valley areas may peak on Tuesday
due to offshore trends and the potential for less marine
influence on that day. Will maintain the Excessive Heat Watch for
Wednesday, covering many far interior areas. However, there is
some concern that onshore trends and an earlier sea breeze
Wednesday may stall warming for some of these areas even as the
ridge peaks in intensity overhead. There is a small chance that
the heat hangs on long enough for some interior areas to need some
type of heat product into Thursday.

Lower confidence in the forecast heading into next weekend as a
low pressure system may move into the region from the south or
southwest. There is a 10 percent chance (leaving a 90 percent
chance that unremarkable early June weather continues) that this
setup is favorable for showers or thunderstorms for interior areas
and drizzle or light showers for closer to the coast. Either way
temperatures should cool at least somewhat, possibly significantly
for interior areas should the more active weather scenario play
out.

&&

.AVIATION...02/2358Z.

At 2345Z at KLAX, the marine layer was 3400 ft deep. The top of
the inversion was at 5000 feet with a temperature of 18 deg C.

Moderate to hi confidence in the 00Z TAFs. MVFR/VFR cigs lingering
across portions of the coast/valleys late this afternoon,
especially south of Pt Conception. IFR/MVFR cigs will likely
spread back inland tonight and affect all coast and adjacent vly
airfields including KPRB and continue into late Mon morning except
scattering out of KPRB by 16Z Mon morning. The timing of the
dissipation and onset of low clouds may be off +/- an hour or two,
with the largest uncertainty of the onset of low clouds tonight
for KSBA and KPRB.

For KWJF and KPMD, there is hi confidence VFR conds will continue
thru the TAF period. Gusty SW-W winds will affect these airfields
for most of the fcst period.

KLAX...Moderate to hi confidence in the 00Z TAF. SCT-BKN030
conditions expected until 02z, then higher probability of MVFR
cigs between 03z-21z, with timing of dissipation and onset of
low clouds potentially being off +/- an hour or two.
There is a 20% chance of an east wind component of 7-8 kt from
09Z-18Z Mon.

KBUR...Moderate confidence in the 00Z TAF. MVFR cigs should move
back in by 06Z this evening and continue thru Monday morning.
The timing of the dissipation and onset of the low clouds may be
off +/- an hour or two.

&&

.MARINE...02/757 PM.

Northwest winds at or just below Gale Force will continue through
tonight over the offshore waters from the Central Coast to San
Nicolas Island. These winds will weaken a little Monday morning,
but confidence is growing for stronger winds Monday afternoon and
evening likely exceeding Gale Force. Weaker winds by 5 to 10 knots
will affect the nearshore Central Coast waters with Small Craft
Advisory (SCA) winds and seas. Moderate confidence in winds
retreating and weakening Tuesday and Wednesday, but still reaching
SCA levels especially north of Point Conception. These winds will
generate building steep seas at short periods, peaking Tuesday
and Wednesday. Computer projections are currently running a foot
or two above reality, especially for the offshore waters.

Moderate confidence that winds will stay below SCA levels for the
nearshore waters from Santa Barbara to Orange County. Winds of 20
to 25 knots should affect the far western portion of the Santa
Barbara Channel Monday afternoon and evening, but likely will stay
too localized to need a SCA for the whole Channel. Choppy seas
should be expected however due to all the winds offshore.
Southeast winds will continue to form each morning, with isolated
winds around 15 knots through passages and channels, and between
islands.

There is a chance for dense fog over the waters from Point Mugu
northward Tuesday through at least Thursday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Watch remains in effect from Wednesday morning
      through Wednesday evening for zones 344-381>383. (See LAXNPWLOX).
     Wind Advisory in effect from 3 PM Monday to 3 AM PDT Tuesday
      for zones 349-351. (See LAXNPWLOX).
     Wind Advisory in effect from 6 AM Monday to 3 AM PDT Tuesday
      for zones 378-381. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zone 645. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Monday for zones
      670-673-676. (See LAXMWWLOX).
     Gale Watch in effect from Monday afternoon through late
      Monday night for zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/Munroe
AVIATION...Gomberg/Sirard
MARINE...Kittell
SYNOPSIS...Hall/RM

weather.gov/losangeles

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