288
FXUS66 KLOX 221206
AFDLOX

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

.SYNOPSIS...22/229 AM.

Increasing onshore flow will bring a return of persistent night
through morning low clouds and fog to the coasts and valleys. Low
clouds will struggle to clear from the beaches during the
afternoon. An upper-level trough of low pressure will dig south
through Morning drizzle is possible on Thursday and Friday. Better
clearing and slightly warmer temperatures are forecast for Sunday
and Memorial Day.

&&

.SHORT TERM (TDY-FRI)...22/307 AM.

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.

The marine layer has lowered to about 1400 ft. Increasing onshore
flow has pushed low clouds into the coasts and the Santa Ynez Vly.
The low clouds have not made much progress into the VTA and LA
Vlys due to the lack of an eddy. Slightly higher hgts will bring a
few degrees of warming. Most max temps will end up 3 to 6 degrees
blo normal.

Slightly sharper troffing and stronger onshore flow will combine
to deepen the marine layer. 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 extnd to the
foothills and mtn passes. Clearing 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...22/356 AM.

Moderate confidence in forecast, except low-moderate confidence
for the inner waters N of Pt. Sal and in the western SBA Channel.

In the outer waters, Small Craft Advisory (SCA) level winds and
seas will continue much of the time thru Sun. There may be a lull
in the winds during the late night thru morning hours, especially
Thu night/Fri morning. For the waters N of Pt. Arguello, there is
a 20-30% chance of gale force wind gusts Wed afternoon/eve.

In the inner waters N of Pt. Sal, there is a 40% chance of SCA
level winds/seas in the afternoon/eve hours today and Thu. SCA
level winds are likely in the afternoon/eve hours Fri thru Sun.

In the SBA Channel and southern inner water, there is a 30-40%
chance of SCA level winds in western portions of the SBA Channel
in the afternoon/eve hours today and Thu, a 50% chance in the
afternoon/eve hours Fri, and a 70% chance Sat and Sun. Otherwise,
SCA conds are not expected.

A long period S to SW swell will continue to subside today. The
risk of larger than normal breaking waves nearshore and stronger
currents at many harbor entrances will decrease later today.

&&

.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
AVIATION...DB
MARINE...DB
SYNOPSIS...30

weather.gov/losangeles

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