995
FXUS66 KLOX 251146
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
446 AM PDT Tue Jun 25 2024

.SYNOPSIS...25/227 AM.

A gradual cooling trend will continue through midweek as high
pressure weakens over the area and onshore flow strengthens. Night
through morning low clouds and fog will slowly return to the
coastal areas. Temperatures will likely rebound next weekend as
high pressure builds back into the region.

&&

.SHORT TERM (TDY-THU)...25/306 AM.

Three fairly unexciting weather days on tap for the southland
starting today. The area will be under the western edge of a large
upper high over srn NM. An upper low will scoot through the PAC NW
Wed and Thu its energy will push the upper high to the SE while
turning the anti-cyclonic flow to a weakly cyclonic one. Hgts will
be the highest today around 592 dam. By Thursday hgts will be down
to about 590 dam. Strong onshore flow to the east and moderate
onshore flow to the north (peaking in the afternoon) will continue
for all three days.

Residual humidity and partly cloudy skies wrapping around the
upper high this morning have prevented the formation of any marine
layer clouds. The partly cloudy skies will advect away to the
north in the morning leaving sunny skies for the afternoon. The
flow does not turn to the SW fast enough to totally eliminate the
threat of mtn convection in the afternoon but the chc is less than
10 percent which is too low to mention in the fcst. The onshore
flow will bring 4 to 8 degrees of cooling to the coasts and vlys.
The interior will see little or no cooling and heat
advisories/warnings are in place for the interior of SLO/SBA
counties as well as the Antelope Vly. See the product LAXNPWLOX
for details. This will be the last day of the heat products as
there will be enough cooling tomorrow to bring temperatures down
to below advisory thresholds.

Look for two days of cooling with an gradual increase in the night
through morning low clouds. Since hgts are still quite high the
marine layer will be smooshed to below 1000 feet and will only
cover the coasts and the lowest vlys. Lowering hgts and a better
developed marine layer along with the strong onshore flow will
bring 2 to 4 degrees of cooling each day. By Thursday the coasts
and vlys will be 1 to 3 degrees blo normal (vly highs from 80-90)
and the interior will be near normal.

.LONG TERM (FRI-MON)...25/321 AM.

The cooling trend peaks on Friday especially across SLO and SBA
counties. Max temps will end up 3-6 degrees blo normal. The marine
layer stratus will be well developed and may push further into the
vlys. Some beaches may not clear at all. The strong onshore flow
will bring near advisory level west winds the Antelope Vly and its
foothills. In addition strong NW winds across the outer waters
will filter through SW SBA and may produce advisory level gusts
across the western portion of the SBA south coast.

High pressure begins to reassert itself over the weekend. Max
temps will rise 1 to 3 degrees Sat and 2 to 5 degree on Sunday.
The marine layer will shrink a little. Breezy west to northwest
winds will continue, peaking each afternoon and evening,
potentially nearing advisory levels for southwest Santa Barbara
County at times.

Not much mdl agreement on the fcst for next Monday. About 50
percent of the ensembles favor further warming with a growing
upper high while the other half bring in troffing and cooler
temps. No threat of monsoon convection so no real impacts no
matter the outcome.

&&

.AVIATION...25/1135Z.

At 11Z over KLAX, there was no marine layer. There was a surface
based inversion. The top of the inversion was around 2500 feet
with a temperature of 27 degrees Celsius.

There were plenty of mid level clouds moving northward across the
forecast area this morning, but they should mostly move to the
north of the region by afternoon. There were only patches of
low clouds in some coastal areas this morning with IFR to VLIFR
conds. Conds should improve to VFR by mid morning. Expect more
widespread stratus across the coastal plain tonight, generally
after late evening, with mostly IFR to VLIFR conds.

KLAX...Moderate confidence in the 12Z TAF. There is a 10% chance
of IFR to VLIFR conds thru 16Z this morning. There is a 20-30%
chance that cigs tonight will not arrive until 11Z or later.

KBUR...High confidence in the 12Z TAF with VFR conds thru the pd/

&&

.MARINE...25/445 AM.

Patchy dense fog with visibilities under one mile will affect
portions of the waters this morning.

There is a 20-30% chance of Small Craft Advisory (SCA) level wind
gusts this evening into early tonight in the Outer Waters
(offshore waters of the Central Coast to San Nicolas Island).

Across the outer waters, northwest winds will increase Wed. There
is a 70-80% chance of SCA level winds and steep seas from Wed
afternoon or evening thru Sat night. There is a 20% chance of
low-end gale force winds Wed night thru Fri.

In the inner waters north of Pt Sal, there is a 40% chance of SCA
winds and seas during the afternoon/eve hours Wed and Fri, with
SCA conds likely (70% chance) Thu afternoon/eve.

S of Pt Conception, there is a 30% chance of SCA conds in western
portions of the SBA Channel during the late afternoon thru late
eve hours Wed and Fri, with a 60% chance in that area late Thu
afternoon-late Thu evening. Otherwise, SCA conds are not expected.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect until 8 PM PDT this evening
      for zones 38-344-345-353. (See LAXNPWLOX).
     Excessive Heat Warning remains in effect until 8 PM PDT this
      evening for zones 382-383. (See LAXNPWLOX).
PZ...NONE.

&&

$$

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