403
FXUS66 KLOX 181012
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
312 AM PDT Sat Oct 18 2025

.SYNOPSIS...18/304 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 Sunday and
Monday mornings. Then a weak upper low will swing across SoCal
Tuesday and Wednesday, bringing cooler weather with a low chance
for drizzle.

&&

.SHORT TERM (TDY-MON)...18/303 AM.

Light northeasterly flow will be common this morning across the
valleys of LA and Ventura counties as well as the interior
mountains of SLO and Santa Barbara counties. A transition to weak
onshore flow this afternoon will lead to up to a degree or two of
cooling for most coastal areas, except for LA County where highs
will tick up a degree or two. Interior sections will warm up,
with most significant warming across far interior mountains and
valleys. Onshore flow will increase Sunday which will allow for
several degrees of cooling across the coasts and coastal valleys.
Onshore flow will be slightly weaker Monday, but very little
change in temperatures are expected.

While onshore flow will reestablish in the afternoon hours, a
near neutral gradient will establish in the early morning hours
Sunday and Monday. Expecting some return of marine layer clouds
come Sunday morning, and while the extent of the development of
low clouds remains somewhat uncertain, the marine layer will be
very shallow thus any clouds that form will likely be confined to
the immediate coasts. With the shallow marine layer, dense fog
would be likely wherever clouds develop. A slight deepening of the
marine layer Monday night should eliminate the threat of dense
fog, at least south of Point Conception.

.LONG TERM (TUE-FRI)...18/310 AM.

A weak upper low about 600 miles southwest of Los Angeles will
finally make its way into SoCal after meandering for several
days. Temperatures will cool Tuesday and Wednesday, leading to
highs anywhere between 5 and 15 degrees below normal. Although
most ensemble solutions are keeping the forecast area dry, light
drizzle is possible Tuesday night into Wednesday morning,
especially across the foothills as the marine layer rapidly
deepens with the passing upper low. Gusty southwesterly winds in
the 20-30 mph range will be common in the wake of the low as it
moves east across the CONUS fairly rapidly.

The latter half of the week will feature temperatures rebounding
back to near normal as a brief ridge fills in. The southern edge
of a trough which is lining up to be a significant rain maker for
the northern half of the West Coast will clip Southwest
California by as early as late Friday night. Although the trough
does not appear to dig far enough south south to bring significant
rain to our area, ensembles are bullish on the Central Coast
receiving light measurable rain. There is less agreement south of
Point Conception, but a number of solutions bring some
precipitation all the way down to LA County.

&&

.AVIATION...18/0529Z.

At 10Z at KLAX, there was no marine layer. The inversion top was
at 1500 ft with a temperature of 23 degrees Celsius.

High confidence in VFR conditions at all sites through at least
this evening, with only a 20% chance of LIFR at KPRB 10-16Z. For
Sunday 10-16Z, there is a 20-30% chance of IFR/LIFR conditions at
KSBP KSMX KSMO KLAX KLGB. High confidence in unusually light
winds.

KLAX...High confidence in VFR conditions through at least this
evening with weaker than usual winds. There is a 30% chance if
LIFR conditions on Sunday 10-16Z.

KBUR...High confidence in VFR conditions through at least tonight
with weaker than usual winds.

&&

.MARINE...18/246 AM.

Winds will be unusually light for the next few days. High
confidence in winds and seas remaining below Small Craft Advisory
(SCA) criteria through at least Monday, except for brief long
period seas around 10 feet off the Central Coast on Monday. There
is an increasing risk of patches of dense fog, growing each day
through early next week.

&&

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

&&

$$

PUBLIC...Lewis
AVIATION...RK
MARINE...Kittell
SYNOPSIS...Lewis

weather.gov/losangeles

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

NWS Flagstaff Office