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000
FXUS66 KLOX 160404
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
904 PM PDT Mon Apr 15 2024

.SYNOPSIS...15/225 PM.

Dry and warmer conditions will prevail across the region
this week and through the weekend. Low clouds and fog should also
affect portions of the coast and valleys during the night and
morning hours through the period.

&&

.SHORT TERM (MON-THU)...15/753 PM.

***UPDATE***

Skies were mostly clear across most of the forecast area early
this evening, with just some stratocu noted over interior SLO
County. Low clouds are expected to move into and expand over the
SLO/SBA County interior areas from the southern San Joaquin Vly
overnight into Tue morning. Low clouds should also develop along
portions of the Central Coast and L.A. County coast into the
southern San Gabriel Vly later tonight into Tue morning.
Otherwise, skies will remain mostly clear overnight and continue
on Tue. Northerly pressure gradients will keep some gusty NW to N
winds over the foothills and mtns thru the night.

***From Previous Discussion***

An upper level ridge will gradually build into the forecast area
tonight through Wed, with H5 heights topping out around 581-582
dam on Wed. Weak upper level troffiness should then approach from
the E Pac Wed night and Thu with lowering H5 heights.

Night and morning low clouds are expected to expand along the
coast from Tue night thru Thu morning, extending into the adjacent
vlys by Thu. The clouds are likely going to persist for many
coastal areas Thu afternoon. Otherwise, mostly clear skies can be
expected during the period except for varying amounts of hi clouds
at times Wed afternoon thru Thu morning.

There will be some offshore pressure gradients to the N and E
thru Tue then turn gradually more onshore thru Thu. Breezy to
locally gusty offshore winds can be expected mainly night and
morning hours thru Wed especially for the foothills, mtns and
interior SLO/SBA Counties. Breezy onshore flow can be expected
each afternoon especially for the coast and vlys, altho should
turn more gusty Thu afternoon in all areas.

Temps will be several degrees above normal each day except
turning cooler than normal for the coast and some adjacent vlys by
Thu. Wed looks to be the warmest day overall across the region
this week. Highs on Wed should be in the 70s to lower 80s for most
inland coast, vlys and lower mtns.

.LONG TERM (FRI-MON)...15/224 PM.

Weak upper level troffiness is forecast to be over the area Fri,
then upper level ridging should move in Sat and Sun before an
upper level trof approaches from the E Pac on Mon. Dry weather
will continue thru the extended period. The marine layer pattern
will continue with varying amounts of night and morning low clouds
and fog along the coast extending into the vlys, altho should
remain near the coast Sat night into Sun morning.

Temps on Fri are forecast to be a few degrees below normal for
the coast and vlys with above normal temps elsewhere. There should
be a warming trend Sat and Sun, with Sun being the warmest day
during the extended period. With the marine layer expected to
deepen by Mon, temps will cool back to several degrees below
normal for the coast and vlys but remain above normal for interior
areas.

&&

.AVIATION...16/0015Z.

Around 23Z, there was no marine layer depth at KLAX.

High confidence in the current forecast for valley and desert
terminals. Moderate confidence in the current forecast for coastal
terminals. There is a moderate-to-high (30-50 percent) chance of
IFR conditions Los Angeles County coastal terminals and KPRB, and
low-to-moderate (20-30 percent) chance of LIFR conditions for
remaining coastal terminals.

KLAX...There is a 50 percent chance of IFR conditions between 11Z
and 17Z. Any east winds should remain less than 7 knots, but
there is a 20 percent chance of easterly winds 7-9 kts between 12Z
and 16Z.

KBUR...VFR conditions are expected through the period. No wind
impacts are expected at this time.

&&

.MARINE...15/903 PM.

Moderate-to-high confidence in the current forecast. Higher
confidence exists in the wind forecast relative to seas.

For the outer waters, Small Craft Advisory (SCA) level winds are
expected to persist through late Tuesday night. There may be a
lull in the winds Tuesday morning, particularly for the northern
waters, but winds are expected to rebuild shortly. There is a
low-to-moderate (20-40 percent) chance of Gale force wind gusts
this evening, and again Tuesday evening, highest from near Point
Conception south to San Nicolas Island. There is a 20-30 percent
chance of SCA level winds Wednesday through Thursday, and a 50
percent chance on Friday and Saturday.

For the Inner Waters north of Pt. Sal, SCA level NW winds are
expected through late tonight. There is a likely (60-80 percent)
chance of SCA level winds late Tuesday afternoon and Tuesday
evening, highest across the southern portion. Winds and seas
should drop below SCA conditions late Tuesday night through
Friday.

For the Inner Waters south of Point Conception, SCA level W-NW
winds are expected in western portions of the Santa Barbara
Channel through late tonight. There is a moderate (30-40 percent)
chance of SCA level winds west to northwest winds in western
portion of the Santa Barbara Channel late Tuesday afternoon into
Tuesday night. Otherwise, SCA conds are not expected from late
Tuesday night through Friday.

&&

.BEACHES...15/903 PM.

A building long-period southerly swell across the coastal waters
between Tuesday night and Thursday will bring a moderate chance of
high surf to south-facing shores. There is a 30 percent chance of
high surf up to 4 to 7 feet on south-facing beaches in Los
Angeles County Wednesday and Wednesday night.

&&

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

&&

$$

PUBLIC...Sirard
AVIATION...Hall
MARINE...Hall
BEACHES...Hall
SYNOPSIS...Sirard

weather.gov/losangeles

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