Acton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

920
FXUS66 KLOX 120626
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1126 PM PDT Sun May 11 2025

.SYNOPSIS...11/843 PM.

Monday temperatures will come crashing down, with gusty coastal
and desert winds in the afternoon and evening. Temperatures will
drop further Tuesday and drizzle will be possible. Cooler
conditions will last through the weekend, with low clouds and fog
pushing back into the valleys.

&&

.SHORT TERM (SUN-WED)...11/842 PM.

Another very warm day across the southland today, but we did see
between 5 and 10 degrees of cooling from yesterday across most
coastal/valley areas as the upper level ridge weakened over the
region, and onshore flow increased at the surface. As a low
pressure system moves into the Pacific Northwest, the associated
trough will dig into the region through Tuesday. As a result,
heights for Los Angeles County will fall from 583 dam (today) to
570 dam by early Tuesday. This will cause a significant cooling
trend for the region Monday into Tuesday, along with a return of
marine layer clouds and increasing onshore winds across the
interior. While onshore winds will mostly be gusting in the 25 to
40 mph range across many coastal and interior areas on Monday and
Tuesday, there will likely be gusts of 40 to 50 mph across the
Antelope Valley and adjacent foothills where a wind advisory will
be posted with the evening update. The strengthening winds will
also bring an increased risk of grass fires across the interior,
especially in the Antelope Valley.

The upcoming trough will be moisture starved, thus overall
precipitation chances are low. At this point, most areas are
likely to only see scattered drizzle from a very deep marine
layer, with a slight chance of showers for the eastern San Gabriel
foothills and the northern Ventura County mountains. Drizzle will
be possible Monday night through Wednesay morning, with the best
chances on Tuesday, when skies are likely to remain overcast
through much of the day.

Tonight, a significant Sundowner Wind event is in progress for
the Santa Ynez range and adjacent western coast. This due to
the combination of tightening pressure gradients (Santa Barbara-
Santa Maria -5 mb) and increasing upper level wind support.
A Wind Advisory is in effect tonight, with gusts of 35-55 mph
already being observed. Wind will be strongest in the typically
windy area across the western half of the Santa Ynez range
(Gaviota to San Marcos Pass),Conditions overnight will stay warm
and dry for the eastern portion of the south coast, especially in
the hills. Evening to overnight Sundowner winds are likely to
continue through at least Tuesday night, however at this point
tonight looks to be the strongest and most widespread event.

*** From previous discussion ***

Elsewhere, the trough of low pressure will yield gusty conditions
on Monday afternoon across coastal areas south of Point
Conception and interior mountains and deserts. Expect widespread
west to southwest gusts in the 25-40 mph range, as a result of
upper level wind support and surface pressure gradients.

.LONG TERM (THU-SUN)...11/235 PM.

Thursday through the weekend, the region will continue to be
under a broad trough pattern, that may sharpen Saturday night into
Sunday, however the system will be dry with no significant
precipitation chances. Temperatures will vary by a few degrees
each day, with the coolest days on Friday and Saturday, and
overnight to morning marine layer clouds are likely through the
weekend. Onshore flow will trend upwards until Saturday, when
winds are likely to be quite gusty for the coasts, inland
mountains, and deserts.

&&

.AVIATION...12/0624Z.

At 0505Z at KLAX, the marine layer was around 700 ft deep. The
top of the inversion was at 1800 feet with a temperature of 20 C.

Hi confidence for TAFs at KPRB, KSBP, KSBA, KWJF and KPMD.

Low confidence in TAFs for KOXR and KCMA with a 40 percent chc of
IFR cigs 12Z-17Z.

Moderate confidence for the rest of the TAFs. Timing of flight cat
changes could be off by +/- 90 minutes and there is a 30 percent
chc of cigs coming in 400 ft higher than fcst.

KLAX....Moderate confidence in TAF. Cigs could arrive as early as
08Z or as late as 11Z. There is a 30 percent chc that cigs will
be OVC012. VFR conds could arrive as early as 18Z. Any easterly
wind component will be less than 7 knots.

KBUR...Moderate confidence in TAF. Low clouds could arrive as
early as 12Z and could clear as late as 1830Z.

&&

.MARINE...11/831 PM.

For the outer waters, there is moderate to high confidence in the
current forecast. GALE Force winds at times are expected to
persist into the late night hours for PZZ673/676, especially
around the Northern Channel Islands. Small Craft Advisory (SCA)
winds are expected to persist in PZZ670 through late tonight,
followed by a period of sub-SCA winds Mon and Mon evening.
Thereafter, SCA winds will persist for much of the time thru Mid-
week for the Outer waters. There is a 10-20% chance of GALE force
winds Tue afternoon/eve.

For the inner waters N of Point Sal, there is moderate to high
confidence in the current forecast. High confidence in SCA winds
through at least Wednesday evening, especially during the
afternoon/eve hours. Thereafter, there is only a 20-30% chance of
SCA level winds during the afternoon/eve hours for the remainder
of the work week.

For the inner waters S of Point Conception, there is moderate to
high confidence in the current forecast. GALE force wind gusts
are expected at times across portions of the Santa Barbara Channel
through late tonight. There is a 60-70% chance of GALE force winds
across the SBA channel (esp. eastern portions) Mon afternoon/eve.
Will let next shift or two decide on whether or not to issue GALE
warning. Thereafter, SCA level winds are expected for entire SBA
channel through Tue, followed by a 60% chance for western portions
Wed afternoon/eve. For remainder of work week, conds are generally
expected to remain below SCA Criteria.

Seas are generally expected to remain below SCA levels through
the work week. However, seas could approach near SCA levels at
times for the outer waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 10 AM PDT Monday for
      zones 349-351-352. (See LAXNPWLOX).
     Wind Advisory in effect from 8 AM to 9 PM PDT Monday for
      zones 381>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 645-655. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Monday for zones
      650-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for zone
      670. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/Schoenfeld
AVIATION...Rorke
MARINE...Black
SYNOPSIS...Schoenfeld

weather.gov/losangeles

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