845
FXUS66 KLOX 110424
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
924 PM PDT Fri May 10 2024

.SYNOPSIS...10/126 PM.

A quiet weather pattern is expected through early next week with
near normal temperatures and no rain except possibly some light
showers over the mountains this afternoon. Increasing night and
morning low clouds are expected across coast and valleys as
onshore flow increases. Mostly minor day to day changes in
temperatures are expected through Sunday, then cooling possible
Monday and Tuesday.

&&

.SHORT TERM (FRI-MON)...10/923 PM.

***UPDATE***

Marine layer clouds and onshore sea breezes kept coastal areas
were cool today, with temperatures in the low- to- mid 60s. Inland
valleys and deserts were much warmer, with highs in the upper 70s
to mid 80s. Instability caused by the upper level low circulating
over Las Vegas, lead to a thunderstorm this evening over the San
Gabriel Mountains, and 0.04 inches of rain was recorded near Mount
Wilson.

Tonight the marine layer is expected to spread as far inland as
the San Fernando Valley and all the way into the San Gabriel
Foothills. The areas with the best chance of clear skies tonight
are the Santa Clarita Valley and high elevation mountain areas
above 3500 ft.

Tomorrow expect slightly warmer temperatures across the region,
by around 2 to 5 degrees. Afternoon mountain thunderstorms will
be possible again tomorrow (5% chance). Conditions will be less
favorable than they were today because the upper low will move
further away from the region towards the east.

Forecast was adjusted with slight temperature increases for
inland areas and minor cloud cover adjustments.

***From Previous Discussion***

Otherwise, more of the same for southwest California. Marine layer
has finally filled in along the Central Coast and has been very
slow to clear elsewhere along the coast. Onshore trends to north
and especially the east are likely the culprit and we may be
looking at several more days of this coming up. There is a little
weak upper ridge that will follow the current trough later
Saturday into Sunday that may result in some brief lowering of the
marine layer depth and allow for earlier clearing and a few
degrees of warming, but subtle changes like are always low
confidence, and given the time of year and the upper pattern it`s
more likely low clouds will be a mainstay for awhile, with some
days struggling to clear at the beaches, especially from Malibu
north.

.LONG TERM (TUE-FRI)...10/208 PM.

The next weak upper low that arrives later this weekend is
expected to linger through Wednesday, leading to a slow decline in
daytime temperatures and likely a deeper, farther inland, and
slower clearing marine layer. Models have also been consistent
showing increasing onshore flow to the east during this period.
The NAEFS gradients table shows around a half degree of increase
each day through May 18, though the deterministic GFS shows a
sharp decline starting next Thursday and actually turning lightly
offshore next weekend. Very low confidence in this though as the
global models are showing a much slower weakening trend in the
gradients, which would go along with the upper level grand
ensemble mean pattern showing a weak trough over the area later
next week.

&&

.AVIATION...11/0114Z.

At 0030Z at KLAX, the marine layer was 1900 feet deep. The top of
the inversion was at 3000 feet with a max temperature of 20 C.

Moderate confidence in TAFs. Good confidence that clearing
Saturday will be similar to today (Friday) but lower confidence
in Cig hgts will a 30 percent chc that cig hgts will be one
category higher than fcst.

KLAX...Moderate confidence in TAF. There is a 30 percent chc that
cigs will remain AOA BKN010. There is a 25 percent chc of SCT
conds 22Z-01Z tomorrow afternoon. No significant easterly wind
component is expected.

KBUR...Moderate confidence in TAF. There is a 30 percent chc that
cigs will be AOA BKN010. Good confidence that VFR transition will
occur between 17Z and 19Z.

&&

.MARINE...10/747 PM.

For the Outer Waters, moderate to high confidence in current
forecast. Today through Saturday afternoon, high confidence in
winds and seas remaining below Small Craft Advisory (SCA) levels.
Saturday evening there is a 60% chance of SCA wind for the outer
waters south of Point Conception. For Sunday through Monday
night, there is a 50-70% chance of SCA winds. Then, SCA
conditions are not expected through Wednesday.

For the Inner Waters north of Point Sal, high confidence in
current forecast as winds and seas are expected to remain below
SCA levels through Wednesday.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. Through Wednesday, winds and seas
will remain below SCA levels for most areas. The only exception
will be the western half of the Santa Barbara Channel where there
is a 20% chance of SCA wind Saturday evening, and a 30-40% chance
of SCA winds Sunday night and Monday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect from 9 PM Saturday to 3 AM PDT
      Sunday for zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Schoenfeld/ASR
AVIATION...Rorke
MARINE...Cohen/Schoenfeld
SYNOPSIS...MW

weather.gov/losangeles

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