135
FXUS66 KLOX 282101
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
201 PM PDT Sun Apr 28 2024

.SYNOPSIS...28/200 PM.

Mostly clear skies and warmer temperatures will prevail across
the region through this week, with just some coastal low clouds
and fog possible at times night and morning hours early in the
week and again late in the week. Gusty west to north winds will
prevail over the mountains and deserts at least through Tuesday.

&&

.SHORT TERM (TDY-WED)...28/153 PM.

Mostly sunny skies covered the forecast area early this afternoon
with little change expected thru the rest of the day.

Gusty W to N winds to Advisory levels will affect portions of the
forecast area at times this afternoon, including the SW SBA
County mtns and coast, VTU County mtns, L.A. County mtns along the
I-5 Corridor, and the western Antelope Vly foothills into the
Antelope Vly. A Wind Advisory is in effect for these areas, where
winds could gust to 45 to 50 mph. Breezy to gusty W-NW winds will
also affect much of the coast and adjacent vlys thru this
afternoon, strongest on the Central Coast where winds could
approach Advisory levels at times.

Some upper level ridging with H5 heights increasing to around 576
dam will help temps to warm up a few more degrees over yesterday
and be near normal to a few degrees above normal for many areas
away from the immediate coast this afternoon. Highs for the inland
coast to the vlys and lower mtns should reach the 70s to around
80.

Flat upper level ridging with H5 heights around 576 dam will
persist over the area tonight thru Tue, then very weak upper level
troffiness should move in by Wed with H5 heights falling slightly
to around 573-574 dam.

Marine layer low clouds and fog are expected to develop over the
coastal waters tonight and move into the L.A. coast and portions
of the Central Coast later tonight into Mon morning. Low clouds
are expected to form in the Salinas River Vly in SLO County later
tonight into Mon morning as well. Low clouds should affect the
L.A. County coast night and morning hours Mon night thru Wed
morning as offshore pressure gradients gradually increase and keep
the low clouds away from other coastal areas. There should also
be more low clouds late night and morning for the Salinas River
Vly on Tue. Otherwise and elsewhere across SW CA, mostly clear
skies will prevail tonight thru Wed.

Strong and gusty NW to N winds are expected to continue tonight
thru early Tue afternoon for the northern VTU County mtns, L.A.
county mtns around the I-5 corridor as well as the western
Antelope Vly foothills into the Antelope Vly, where gusts 45 to 55
mph will be possible at times. Gusty NW to N winds should also
persist at times for the SBA County mtns and SW SBA County coast.
Wind Advisories will be in effect for many of these areas during
the period. Please see the latest Non-Precipitation Weather
Message (LAXNPWLOX) for further details on the Wind Advisories.

For the coast and vlys, breezy to gusty sub-Advisory level W to
NW winds can be expected each afternoon, strongest along the
Central Coast.

Temps are forecast to be near normal to a few degrees above
normal thru Wed, altho Tue should be the warmest day overall.
Highs for the inland coast, vlys and lower mtns should reach the
70s to lower 80s each day.

.LONG TERM (THU-SUN)...28/157 PM.

The EC and GFS mean ensembles and deterministic are in generally
good agreement Thu thru Sat with broad but generally weak upper
level troffiness over the forecast area. By Sun, the deterministic
models diverge quite a bit with the GFS forecasting a significant
for early May storm system affecting the region with rain and
high elevation mtn snow, while the EC has dry weather with rising
H5 heights over the region. The GFS mean ensembles bring a 10%-20%
chance of measurable rain to the area Sun, as only 4 out of 30
ensemble members show rain moving into the area at that time. For
now we will go with a dry forecast for day 7.

High pressure is fcst to move into NV on Thu morning and will set
up offshore flow from both the N and E. A low end Santa Ana wind
event will develop and keep any low clouds well offshore. Mostly
clear skies are then expected to continue across the forecast area
Thu night thru Sat, except for some night and morning low clouds
and fog along the Central Coast Fri night into Sat morning.
Increasing clouds are possible by Sun, and there may be some low
clouds and fog along the coast into the adjacent vlys Sat night
into Sun morning.

With the offshore flow Thu and even some into Fri, temps are
expected to be warmest for the week, with inland coast, vlys and
lower mtns expected to top out in the mid 70s to mid 80s. A
smattering of upper 80s is possible on Thu for the warmest vlys.
It will turn cooler next weekend, with highs 2-6 deg below normal
for many areas by Sun.

&&

.AVIATION...28/1758Z.

At 17Z at KLAX, the marine layer was 1700 ft deep. The top of the
very weak inversion was around 2700 ft with a temp of 13C.

High confidence forecast except coastal TAFs KSMX and south
including KLAX. There is a 50-70 percent chance of MVFR/IFR cigs
between roughly 08-18Z for KLAX/KLGB/KSMO, 30-50 percent chance
for KSMX/KOXR and a 10-20 percent chance for KSBA/KBUR.

Gusty NW-N winds expected for northern and interior TAFs may be
off by 5 kts at times.

KLAX...Moderate confidence in TAF. There is a 20% chance of
low MVFR to IFR cigs 13Z-17Z today. There is a 30% chance of
conds remaining VFR tonight. No east wind component expected.

KBUR...High confidence in TAF with VFR conds thru the pd.

&&

.MARINE...28/911 AM.

Small Craft Advisory (SCA) winds will very likely increase to gale
force late morning through early evening across the outer waters
today. A very long period of gale force winds is expected,
continuing thru at least Tue night. Winds will occasionally drop
below gale thresholds, but for the most part, gales are expected
across much of the outer waters much of the time. SCA conds are
expected Wed thru Thu, with a 30% chance of gales persisting into
Wed evening.

In the inner waters N of Pt. Sal, SCA level winds are likely thru
Tue night, especially in the afternoon/eve hours. There is a 50%
chance of SCA conds during the afternoon/eve hours Wed/Thu. Seas
are expected to be near SCA levels during the periods of weaker
winds. There is a 25% chance of gale force winds during the
afternoon/eve hours today thru Tue.

In the SBA Channel, SCA level W-NW winds are expected across
western portions during the afternoon thru late night hours today
thru Wed. There is a 50% chance of SCA conds across the eastern
portions late this afternoon and evening, and a 40% chance during
the afternoon and evening hours Mon thru Tue.

In the southern inner waters, there is a 40% chance of SCA level W
to NW winds across northwestern portions, mainly from Anacapa Island
to Malibu during the late afternoon thru late evening hours thru Tue.

Widespread strong to gale force winds will keep dangerous sea
conditions across much of the coastal waters (particularly the
outer waters) thru the middle of the week, with short-period,
steep, and choppy waves. There may be dangerous breaking waves
near west-facing harbors. Mariners should plan accordingly.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 3 PM PDT Monday for
      zones 349-351. (See LAXNPWLOX).
     Wind Advisory now in effect until 3 PM PDT Tuesday for zones
      377-378-381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for zone
      650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zone 670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Wednesday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Sirard
AVIATION...Munroe
MARINE...DB/RM
SYNOPSIS...Sirard

weather.gov/losangeles

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