819
FXUS66 KLOX 310543
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1043 PM PDT Thu Oct 30 2025

.SYNOPSIS...30/805 PM.

A switch to onshore flow will bring some gradual cooling to most
of the region through Friday, with a slight rise in temperatures
over the weekend as high pressure rebuilds on Saturday. There will
be a return of morning low clouds and dense fog to coastal areas
the next few days. Dry conditions are expected through at least
early next week.

&&

.SHORT TERM (THU-SUN)...30/724 PM.

Another day of light offshore winds brought another round of very
warm temperatures into the lower to mid 90s across the valleys and
inland coastal plain. The upper ridge of high pressure that
brought our heat the past few days will start to break down
tonight, with pressure gradients trending onshore this evening.
Conditions looking favorable for dense fog to develop at some
point overnight across portions of our coast. Current satellite
imagery showing a return of low clouds and fog this evening
across the Central Coast and starting to develop off the coasts
of Orange/San Diego counties. LAX ACARS data showing a shallow
and strong marine inversion over the LAX basin, currently around
500 feet. This in combination with near neutral LAX-DAG pressure
gradient creates the favorable pattern for dense fog. Overnight
shift may need to issue a dense fog advisory for portions of the
coast. With some lowering of heights and gradients trending
onshore on Saturday, looking for most coastal/valley areas to
see some cooling. A ridge of high pressure rebuilds over the
weekend. With pressure gradients remaining weak and the marine
inversion remaining shallow, there will continue to be the
potential for dense fog at times across coastal areas.

***From previous discussion***

Through Sunday, winds should be no issue with weak offshore and
onshore gradients. As for temperatures, will anticipate 5-10
degrees of cooling for coasts/coastal valleys on Friday with
greater marine influence and onshore flow in the afternoon. For
Saturday and Sunday, daily temperature changes for all areas will
only be a couple degrees, mainly hostage to the whims of the
marine layer and surface pressure gradients. No matter what,
temperatures through Sunday will remain above normal for the
season.

.LONG TERM (MON-THU)...30/109 PM.

For the extended, no major changes to previous thinking, based on
latest deterministic and ensemble guidance. At upper levels,
southwesterly flow will prevail across the area through Thursday.
At the surface, weak onshore flow is expected.

Forecast-wise, the above pattern will bring a return of the marine
layer stratus/fog to the coasts and valleys through the period. some
coastal valleys coasts and coastal valleys. Other than any stratus
and fog, skies should remain mostly clear through Tuesday. However
for Wednesday and Thursday, there will be some increase in mid and
high level clouds as the tail end of a weak front will move across
the area. At this time, there looks to be a decent chance of light
rain (around 0.25 inches or less) across San Luis Obispo and
Santa Barbara counties Wednesday night and Thursday morning, but
very low chances for Ventura and LA counties. With this cloud
cover and rain chances, temperatures will drop to around seasonal
normals by Wednesday/Thursday.

&&

.AVIATION...31/0541Z.

At 0505Z at KLAX, the marine layer was 500 feet deep. The top of
the inversion was at 2200 ft and a temperature of 24 C.

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

Moderate confidence in coastal TAFs plus KPRB. Flight Cat changes
could be off by as much as 90 minutes. Good confidence that
Cig/Vis will be LIFR.

KLAX...Moderate confidence in TAF. Low clouds could arrive as
late as 10Z. VFR conds could occur as early as 1730Z or as late as
20Z. TAF vis reflects actual sfc vis not tall tower vis. There is
a 20 percent chance of an 8kt east wind component 12Z-16Z.

KBUR...High confidence in CAVU TAF.

&&

.MARINE...30/802 PM.

NW winds between 20-30 knots are observed across the waters off
the Central Coast beyond 10 NM from shore and down to San Nicolas
Island, and 15-25 knots nearshore along the Central Coast.
Highest seas will be to the northwestern portion of the coastal
waters and peaking in the 10-12 foot range. A decrease in both
winds and combined seas is likely Friday morning through Saturday
afternoon, especially within 40 NM of the coast, but there is a
30% chance for Small Craft Advisories (SCA`s) to be extended.
Saturday afternoon through Monday morning, a combination of winds
and seas across the outer waters (and potentially nearshore
Central Coast waters) will reach SCA criteria, with seas peaking
12-14 feet Saturday afternoon into Sunday morning. Winds and seas
are then expected remain below advisory criteria through
Wednesday.

Conditions across the nearshore waters south of Point Conception
are expected to remain relatively mild into the middle of next
week.

A more expansive blanket of dense fog is anticipated tonight into
Friday morning, including for nearshore waters. A Marine Weather
Statement is in effect detailing the locations and impacts of the
fog.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until midnight PDT tonight for
      zones 340-346. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 9 AM PDT Friday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/Thompson
AVIATION...Rorke
MARINE...Lewis/Ciliberti
SYNOPSIS...Gomberg

weather.gov/losangeles

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

NWS Flagstaff Office