033
FXUS66 KLOX 020739
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1239 AM PDT Mon Jun 2 2025

.SYNOPSIS...01/542 PM.

Broad troughing over the West Coast will bring a cooling trend to
the region through at least Wednesday. A return of low clouds and
fog to all valleys is expected through Tuesday, as strong onshore
flow and a persistent marine layer continue to affect the area.
Clouds could reach the coastal slopes of the mountains on Tuesday
morning as the marine layer deepens. Night through morning
drizzle will be possible for the next couple of nights and
mornings. Some warming nay occur late in the week as high
pressure aloft builds over the region.

&&

.SHORT TERM (MON-THU)...01/825 PM.

The upper level low pressure system that brought the active
thunderstorms across our region yesterday has now shifted
eastward this evening, currently centered just south of Imperial
County in northern Baja. Most of the associated moisture and
instability has now shifted south and east of LA county.
As a result, there was no convective storms this afternoon
across our forecast area, just some mid level clouds and
associated cloud build-ups over the mountains. This low pressure
system will continue to track eastward, but another upper
level cutoff low pressure system will approach our coast
on Monday.

As this next system approaches on Monday, we will see lowering
heights with a return of onshore flow at the upper levels, along
with strengthening onshore flow at the surface, and a developing
eddy circulation. As a result, expecting a rapid deepening of the
marine layer tonight into Monday morning, with low clouds and fog
likely reaching the lower coastal slopes. There will also likely
be areas of drizzle due to the deepening marine layer. High
resolution models also suggesting the possibility of measurable
light rainfall across favored orographic areas such as the Santa
Ynez Mountains and the Santa Barbara South Coast, as well as the
Santa Lucia Mountains and the San Luis Obispo Central Coast.
In evening update, have included some low Pops (10-20%)
in these areas to account for this measurable light rain
potential. Looking for most of the region to see additional
cooling on Monday. In addition, there will be gusty onshore winds
across the interior, with gusts mostly in the 25 to 40 mph range,
except locally up to 45 mph in the Antelope Valley foothills.

***From previous discussion***

Strong onshore flow will develop over the coming days as a second
upper-level trough off the North Coast of California digs south
into the region. A cooling trend with a deepening marine layer
depth will take place over the next couple of days and return low
clouds and fog to all of the valleys by Tuesday. The threat of
night through morning drizzle will develop over the coming nights
and mornings as dynamics with the trough will move over the
region. The highest chance of drizzle will be from Santa Barbara
northward tonight and into Monday morning, and from Santa Barbara
southward on Monday night into Tuesday morning. PoPs were nudged
higher inline with multi-model ensemble members, but there is a
chance that the Santa Barbara South Coast could see very light
measurable rain late tonight and into Monday.

As instability with the trough moves into the region Tuesday,
there is a slight chance of showers and thunderstorms over the
mountains during the afternoon and evening hours. While the
moisture parameters are weaker than the current air mass, there is
enough moisture present. EPS precipitable water value means
approach 1.10 inches, which is about 150 to 175 percent of normal
for this time of year. This will need to be watched closely over
the coming days.

.LONG TERM (FRI-MON)...01/316 PM.

Persistence is probably the best forecast for the coastal areas
for late this week. A persistent onshore flow and marine
intrusion will bring little change to the forecast for Wednesday
through at least Friday. Night through morning low clouds and fog
should expected across the coastal areas. Ensemble members
introduce a warming trend away from the coast beyond Friday and
through the weekend as EPS and GEFS 500 mb height means rise.
There is a pretty good chance that the region will end up in a
June Gloom type pattern with clouds hugging the beaches and warmer
than normal days across the interior portions of the area.

&&

.AVIATION...02/0739Z.

At 0530Z at KLAX, there was no recent sounding data available.

High confidence in TAFs for KPMD and KWJF.

Moderate confidence in TAFs for KPRB, KSBP, KSMX, KSBA, KOXR and
KCMA. Cig hgts may be off by +/- 300 ft and flight cat changes off
by +/- 90 minutes. There is a 30 percent chc of SCT conds 22Z-02Z
at sites with no clearing fcst.

Low confidence in TAFs for KSMO, KLAX, KLGB, KBUR and KVNY. There
is a 30 percent chc that cigs will remain AOA 010. Flight cat
changes could be off by +/- 2 hours. There is a 30 percent chc of
SCT conds 22Z-02Z at sites with no clearing fcst.

KLAX...Low confidence in TAF. There is a 30 percent chc that cigs
remain AOA 010. There is a 30 percent chc of SCT conds 22Z-02Z
There is a 25% chance of an 8 kt east wind component 11Z-16Z.

KBUR...Low confidence in TAF. There is a 10% chance no low clouds.
There is a 30 percent chc of cigs remaining AOA 010. The timing
of flight cat changes could be off by +/- 2 hours.

&&

.MARINE...01/750 PM.

For the Outer Waters, there is a 40-50% chance of localized Small
Craft Advisory (SCA) level wind gusts for the western portion of
the northern Outer Waters, around Point Conception, and south to
San Nicolas Island until midnight. Additionally, there is a 60%
chance for seas to reach or exceed 10 feet in the western portion
of the northern and central Outer Waters late tonight into Monday
afternoon, with a 30% chance of seas lingering into Monday night.
Thereafter, conditions look to remain below advisory criteria
through the week.

For the nearshore waters along the Central Coast, high confidence
in conditions remaining below SCA criteria through the week.

For the Santa Barbara Channel, high confidence in conditions
remaining below SCA criteria through the week. However, there is
a 20% chance of SCA level wind gusts over the far western portion
and near Santa Cruz Island through late this evening.

For the Inner Waters off the Los Angeles and Orange County coasts,
high confidence in conditions remaining below SCA levels through
the week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Tuesday afternoon
      for zones 354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/Hall
AVIATION...Rorke
MARINE...Ciliberti
SYNOPSIS...Hall/Ciliberti

weather.gov/losangeles

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