551
FXUS66 KLOX 081641
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
941 AM PDT Tue Oct 8 2024

.SYNOPSIS...08/933 AM.

Above normal temperatures will continue across valley and inland
areas through Friday with normal to slightly below normal
temperatures at the coasts. Night through morning low clouds will
continue along the coast, with dense fog and low visibilities at
times.

&&

.SHORT TERM (TDY-THU)...08/941 AM.

***UPDATE***

No big changes in the forecast expected today. Stratus is
extremely shallow, around 1000 feet in the LA Basin and just
slightly lower along the Central Coast. There is currently a 2mb
onshore trend so even though the status is shallow, the
combination of the onshore trend and lowering sun angle as we move
into fall is slowing down the dissipation rate. So this may lead
to some cooling near the coast today but not much change
elsewhere. And no big changes in the later forecast periods
either.

***From Previous Discussion***

Very benign weather on tap for the short term (and long term). A
dry, weak and saggy trof will move overhead today and Wednesday.
At the sfc the gradients will remain very weak. The lowering hgts
and weaker subsidence will combine to bring 4 to 8 degrees of
cooling to the vlys and inland areas. The coasts may warm a degree
or two if the low clouds clear out a little sooner but more like
the marine layer will allow for little day to day change. Today`s
cooling will keep all max temps under advisory and warning levels.
Despite the cooling, however, max temps away from the coast will
be 8 to 12 degrees above normal.

The lower hgts will allow the marine layer to lift a little and
this will let the low clouds to push a little further inland
(although not too far since the onshore push is so weak). The
deeper marine layer will also produce less dense fog.

Not much to talk about for Wed. Max temps will change little and
a night through morning low cloud pattern will continue across the
coasts and lower vlys.

On Thursday a little ridge noses in. At the same time a grip of
mid and high level clouds move over the area. Skies will be partly
to mostly cloudy. The clouds should balance out the rising hgts
and max temps will not change much at all.

.LONG TERM (FRI-MON)...08/329 AM.

Not much to talk about in the extended forecast either. Hgts will
slowly fall from 587 dam to 585 dam as the weak ridge is replaced
by a weak trof.

There will be weak to moderate onshore flow to the east. In the
N/S direction there will be weak offshore flow in the mornings and
weak onshore flow in the afternoon. The forecast offshore flow
from the north is now weaker than it was earlier and this would
limit the amount and strength of any north winds.

Skies will be mostly clear through the period save for the night
through morning low clouds along the coast.

The falling hgts and small increase in onshore flow will bring
several days of cooling (With Saturday having the most noticeable
cool down) and by Sunday most areas will see below normal
temperatures.

&&

.AVIATION...08/1315Z.

At 11Z at KLAX, the marine layer depth was around 800 ft. The top
of the inversion was near 2000 ft with a temperature of 25 C.

High confidence in TAFs for KPRB, KBUR, KVNY, KPMD, and KWJF.

Moderate confidence in coastal TAFs. Low clouds and fog were
widespread in all coastal areas and locally in the Santa Ynez
Valley, San Gabriel Valley, and lower VTU County valleys. Conds
were mostly LIFR to VLIFR. Expect skies to clear by mid to late
morning, except this afternoon near the beaches. Clouds will return
to beach areas this evening, then across the entire coastal plain
and into the lower valleys overnight. Conds will be LIFR to VLIFR.

KLAX...Moderate confidence in TAF. There is a 20-30% chance that
cigs will clear as early as 18Z. There is a 20% chance that cigs
will arrive as early as 23Z this afternoon. Good confidence that
any cigs will be in the LIFR to VLIFR category. No significant
east wind component is expected.

KBUR...High confidence in 12Z TAF. There is a 10% chance of
3SM-5SM vsby from after 11Z tonight.

&&

.MARINE...08/853 AM.

For the Outer Waters (off the Central Coast south to San Nicolas
Island), moderate confidence in the forecast. Small Craft
Advisory (SCA) level winds will likely (60-70% chance) affect the
northern zone (PZZ670) beginning this morning, and the central
zone (PZZ673) (50-60% chance) this afternoon. Winds should drop
below SCA levels late tonight, except possibly early Wed in the
northern zone. In the southern zone (PZZ676), there is a 20-30%
chance of SCA level winds this afternoon into tonight. SCA level
winds are likely (60-70% chance) in the northern two zones
(PZZ670/673) Wed afternoon thru Thu night, and again Sat afternoon
into Sat night. Thru Thu night, winds will be strongest in the
western portion of the outer waters. In the southern zone
(PZZ676), there is a 30% chance of SCA winds Wed afternoon thru
Thu night, then SCA level winds are likely (60-70% chance) Sat
afternoon into Sat night.

For the inner waters, there is a (20-30%) chance of SCA winds
north of Point Sal in the afternoon and evening today thru
Thu, and again Sat. Otherwise, SCA winds are not expected.

A shallow marine layer will continue to generate areas of dense
fog across portions of the coastal waters through at least Wed
morning. Visibilities of one nautical mile or less are expected.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Wednesday for zone 673. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Rorke
AVIATION...DB
MARINE...DB/Black
SYNOPSIS...JMB/RM

weather.gov/losangeles

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