Acton Weather

415
FXUS66 KLOX 191950
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1250 PM PDT Sun Oct 19 2025

.SYNOPSIS...19/829 AM.

Very nice weather will continue into early next week with maximum
temperatures within 5 degrees of normal for most of the region
through Monday. Dense coastal fog will be possible both this
morning and Monday morning. Then a weak upper low will swing
across southern California Wednesday, bringing cooler weather with
a chance of drizzle or light rain. There is another chance of
rain next weekend.

&&

.SHORT TERM (TDY-WED)...19/825 AM.

***UPDATE***

Latest Satellite imagery shows dense fog across the nearshore
waters along the Central Coast. The marine layer has struggled to
move inland past the immediate coastline due to lack of upper-level
support and neutral pressure gradients. Scattered to broken high
clouds around 25kft are common this morning across the CWA, except
for SLO county. Winds are pretty light across the region, with the
highest report only 21 mph at Gaviota. At 830pm, temperatures are
similar to yesterday morning, except along the Central Coast where
readings are 5 to 10 F cooler due to Marine Layer influence.

***From Previous Discussion***

Benign weather is on tap for the next three days. At the upper
levels there will be a very static pattern with a large upper low
spinning but not moving a couple hundred miles to the WSW of KLAX.
A very weak ridge will sit atop of Srn CA with 586 dam hgts. The
onshore gradients will be near neutral through the period.

The marine layer is very shallow, but with little lift or an
onshore push the low clouds have been reluctant to form and really
only cover the beaches of the Central Coast. Where there are low
clouds, however, there will be dense fog. Skies, otherwise, will
be partly cloudy as a grip of cirrus moves up and over the area
from the south. There will be a little more morning stratus each
morning Mon and Tue, but mostly over the Central Coast and the LA
coast.

Max temps will cool today across the csts and vlys as there will
much less offshore flow. Still max temps will be near normal with
80s in the vlys and mostly mid 70s to lower 80s across the coasts.
Not much change in temps on Monday and then some more cooling
Tuesday as hgts fall some as the low begins a slow move to the NE.

.LONG TERM (THU-SUN)...19/303 AM.

Mdls and their ensembles are in good agreement for Tuesday night
and Wednesday. Both show the upper that has been spinning in place
to the SW of the area finally moving. It will move to the NE and
pass over the forecast area Wednesday morning after dawn. A small
fraction of ensembles are slower and have the upper low move over
more towards the afternoon which might trigger some mtn
convection. This is a less than 10 percent chc. What most likely
will happen is the that approaching upper low will lift the marine
layer to over 4000 ft and will produce a low cloud deck that
covers all of the csts and vlys as well as the coastal slopes and
some mtn passes. The amount of lift assoc with the low passage
should be enough to wring out some drizzle or light rain esp in
near the foothills where the orographic lift will provide a little
extra oomph. Max temps will drop 5 to 10 degrees and most non mtn
temps will end up in the upper 60s or lower 70s. These max temps
are 6 to 12 degrees below normal.

Weak ridging will build in on Thursday and will remain over the
area on Friday. Hgts will rise to 582 dam. There will only be weak
onshore flow to the east and morning offshore flow from the north.
The rising hgts and the reduced pressure gradients will reduce the
amount of low clouds esp south of Pt Conception. Aside from the
morning low clouds skies will be mostly clear. Look for 3 to 6
degrees of warming on Thu and another 2 to 4 degrees on Fri. By
Friday max temps will be near normal.

Over the weekend a series of storms will impinge upon Nrn CA. Most
of the ensembles keep the rain north of SLO county but a fair
amount (~30 percent bring rain to the Central Coast) and far fewer
bring it all the way to LA county. Most of this is forecast more
for Sat night and Sunday. So Saturday looks dry albeit cloudier
and cooler. If the rain does arrive Saturday night or Sunday it
does not look like much with little, if any, problems.

&&

.AVIATION...19/1942Z.

At 1746Z at KLAX, the marine layer was 500 ft deep, with an
inversion up to 2600 ft with a maximum temperature of 22 C.

High confidence in KPMD, and KWJF.

Moderate to high confidence in KPRB, KSBA, KBUR, and KVNY. There
is a 10% chance of a few hours of BKN003-BKN010 cigs between
12Z-17Z Mon.

Moderate confidence for all other sites. Timing of cig arrival
may be off by 3 hours tonight and there is a chance of all VFR
conditions through the period at KCMA (30%), KOXR (20%), and
KLGB/KLAX/KSMO (10%).

KLAX...Moderate confidence in TAF. For tonight, low clouds may
arrive as early as 06Z or as late as 12Z and minimum cig height
is likely between OVC004-010. No significant east wind component
is expected.

KBUR...Moderate to high confidence in TAF. There is a 10% chance
for OVC003-OVC010 cigs after 12Z Mon.

&&

.MARINE...19/257 AM.

Seas across the northern outer waters have been hovering right
around 10 feet for the last few hours, thus a brief Small Craft
Advisory (SCA) has been issued through later this morning. If seas
continue to be observed well above current guidance, the SCA may
need to be extended. A long period swell will continue to bring
seas of 8-11 feet across the outer waters into at least mid-week,
highest north. Localized northwesterly wind gusts of 20-25 knots
will occur in portions of the outer waters this evening,
especially in far northwestern portions, near Point Conception,
and near San Miguel and western Santa Rosa Islands. Otherwise,
winds are expected to remain SCA levels until Wednesday afternoon,
then northwesterly winds will increase south of Point Conception
and across portions of the southern Inner Waters, especially
across the Santa Barbara Channel. Moderate confidence in SCA level
winds expanding across the outer waters Thursday into Friday, but
remaining sub-advisory across the inner waters.

Dense fog will continue across portions of the coastal waters
through this morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Rorke/Black
AVIATION...Schoenfeld
MARINE...Lewis
SYNOPSIS...Lewis/CC/Black

weather.gov/losangeles

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