585
FXUS66 KLOX 221546
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
846 AM PDT Wed May 22 2024

.SYNOPSIS...22/845 AM.

Low clouds will struggle to clear from the beaches this afternoon,
but most locations will see some afternoon sunshine. An upper-
level trough of low pressure will dig south tonight, thus drizzle
is possible on Thursday and Friday. Better clearing and slightly
warmer temperatures are forecast for Sunday and Memorial Day.

&&

.SHORT TERM (TDY-FRI)...22/844 AM.

***UPDATE***

Marine layer clouds have persisted this morning up to around 1400
ft, and are on track to retreat for most locations by the early
afternoon, expect for some beaches. Even with morning clouds,
slightly higher upper level hieghts will bring a few degrees of
warming today. However most high temperatures will still be 3 to
6 degrees below normal.

No major changes to the forecast, expect the the addition of
overnight-to-morning drizzle for tomorrow and Friday morning.
This is due to the increase troughing that has the potential to
lift of the marine layer quickly enough.

***From Previous Discussion***

Broad pos tilt troffing will continue over the area for the next
three days. Onshore flow will increase as well and a night
through morning low cloud pattern will dominate the fcst.

Slightly sharper troffing and stronger onshore flow will combine
to deepen the marine layer tonight. The marine layer may rise
fast enough to produce some drizzle esp near the foothills. Low
clouds will end up covering all of the csts/vlys and will extend
to the foothills and mtn passes. Clearing tomorrow will be slower
than today and many beaches will likely not clear at all. Max
temps will drop 2 to 5 degrees due to the clouds, lower hgts and
stronger sea breezes. Max temps will wind up in the 60s across the
coasts and in the lower 70s in the vlys.

Another little trof moves through early Friday. And again it will
bring a deep marine layer and possible drizzle. It will come with
more cold air than Thursday`s trof and this will bring a stronger
onshore push. Look for even slower clearing as well as more
coastal areas not clearing at all. The cold air and strong onshore
flow will likely bring advisory level gusts to the western
Antelope Vly and foothills. The csts/vlys will cool 2 to 4 degrees
but all of the cold air advection will drop the interior temps 5
to 10 degrees. Max temps will end up mostly in the 60s and the
interior will only peak in the 70s. These temps are 6 to 12
degrees blo normal.

.LONG TERM (SAT-TUE)...22/323 AM.

The GFS and ECMWF as well as their respective ensemble means are
in good agreement for the weekend into early next week. The trof
will slowly give way to weak ridging. Hgts will rise from 572 dam
to 584 dam. Onshore flow will persist but will weaken.  The night
through morning low cloud pattern will continue, but the higher
hgts will smoosh the marine layer each day and by Monday the low
clouds should mostly be out of the vlys. Each day the low clouds
should clear a little faster and more completely.

Max temps will rise each day esp Sun and Mon when most areas will
see 3 to 6 degrees of warming each day. Memorial Day looks quite
nice with max temps from the mid 60s to mid 70s across the csts
and 70s and lower 80s in the vlys. Mondays temps will be just
below normals and with additional warming Tuesday most areas will
be within a a degree or two of normal.

&&

.AVIATION...22/1206Z.

At 11Z at KLAX, the marine layer was 1800 ft deep. The top of the
inversion was at 4900 feet with a temperature of 16 C.

High confidence in KPMD and KWJF TAFs.

Moderate confidence in remainder of TAFs. Widespread low clouds in
coastal and most coastal valley areas. Conds were mostly low MVFR
to IFR, except LIFR to VLIFR on the Central Coast and in the
foothills. Skies should clear by mid morning in the valleys and
early afternoon on the coastal plain. Expect widespread low clouds
in coastal and valley areas tonight, with low MVFR to high IFR
conditions, except LIFR to VLIFR conds on portions of the Central
Coast and in the foothills.

KLAX...Moderate confidence in TAF. There is a 20% chance of cigs
slipping into the IFR category thru 17Z. There is a 20% chance
that cigs will linger until 21Z. There is a 20% chance that cigs
will hold off tonight until 06Z or later. There is a 30% chance of
an east wind component of 7-8 kt from 09Z-17Z.

KBUR...Moderate confidence in TAF. There is a 20% chance that cigs
could linger thru 18Z. There is a 20% chance that cigs tonight
will arrive as early as 09Z.

&&

.MARINE...22/734 AM.

For the Outer Waters, moderate to high confidence in current
forecast. Through tonight, high confidence in Small Craft Advisory
(SCA) level winds. For Thursday through Sunday, there is a 60-80%
chance of SCA level winds continuing.

For the Inner Waters north of Point Sal, moderate confidence in
current forecast. Today through Thursday, there is a 30-40% chance
of SCA level winds in the afternoon and evening hours. For Friday
through Sunday, there is a 50-60% chance of SCA level winds,
especially in the afternoon and evening hours.

For the Inner Waters south of Point Conception, moderate to high
confidence in current. For most of the area, high confidence in
winds and seas remaining below SCA levels today through Sunday.
However across the western half of the Santa Barbara Channel,
there is a 30-40% chance of SCA level winds today through Friday
then a 60-70% chance on Saturday and Sunday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 2 PM PDT this
      afternoon for zones 87-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Friday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke/Schoenfeld/RAT
AVIATION...DB
MARINE...RAT
SYNOPSIS...30/RS

weather.gov/losangeles

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