Acton Weather

891
FXUS66 KLOX 180631
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1131 PM PDT Fri Apr 17 2026

.SYNOPSIS...17/821 PM.

Dry and warmer weather is expected into the weekend, though a
cooling trend will begin Sunday as a low pressure system
approaches. Rain chances will begin as early as Monday night along
the Central Coast and Tuesday in Los Angeles.

&&

.SHORT TERM (FRI-MON)...17/1018 PM.

***UPDATE***

Temperatures warmed well over the Ventura and LA coasts and
valleys supported by Santa Ana winds. Highs ranged from the upper
70s to mid 80s for these areas, with cooler 60s to mid 70s
elsewhere. Easterly wind gusts of 45 to 55 mph were limited to
higher elevations in the San Gabriel and Santa Susana Mountains,
with 25 to 40 mph gusts for favored valleys and the western
Antelope Valley. Winds subsided quickly this afternoon, but
expecting sub-advisory level east winds (25 to 35 mph gusts) to
redevelop over Santa Ana favored higher terrain early tomorrow
morning. This will lead to further warming, however warming may be
limited by mid to high level clouds moving in. Highs should range
about 6 to 12 degrees above normal, with widespread upper 70s to
mid 80s. Current forecast looks on track, with no significant
changes needed at this time.

***From Previous Discussion***

Santa Ana winds peaked mid to late morning and have since dropped
below advisory levels. Pressure gradients and upper support were
both weaker than expected for this event, especially away from the
mountain areas.

Meanwhile, temperatures definitely warmed with the offshore flow
with highs mostly in the 70s across coast and valleys and a few
lower 80s across inland Ventura County.

Additional warming is expected in all areas Saturday with
lingering offshore flow and the departure of the cold air
advection that limited interior warming today. Most inland areas
should warm up at least 5 degrees over today, possibly as much as
10 degrees. Coastal areas got most of their warming today but
should warm a few more degrees Saturday. Some lingering offshore
winds are likely Saturday morning, mainly mountains and valleys,
but below advisory levels.

A cooling trend will begin Sunday and continue Monday as a cold
and cutoff upper low slowly meanders down the coast. Increasing
morning stratus is possible near the coast Monday with increasing
onshore flow ahead of the upper low. Most of the ensemble
solutions keep rain north of SLO County at least through Monday
evening.

.LONG TERM (TUE-FRI)...17/206 PM.

Still lots of uncertainty with the details of the incoming cutoff
low. Rain chances remain quite high, 70-80% north and 40-60%
south, but timing and amounts are still very much in question. The
best chance of rain is Tuesday, but could be as early as late
Monday along the Central Coast, and rain chances could linger as
late as Wednesday night. The hangup in the forecast hinges on the
speed of the approaching low and how far south it ultimately
drops. With cutoff lows this this is a very difficult task 3-4
days out. While most of the ensemble solutions keep rain amounts
south of Pt Conception under a half inch and under and inch in the
north, there are some solutions for the Central Coast as high as
2 inches. That would likely require the low to drop much farther
than most of the ensembles are suggesting creating a colder and
more unstable air mass aloft that could generate heavier showers
and possible thunderstorms. It`s likely that confidence in this
forecast will remain very low through the weekend.

&&

.AVIATION...18/0629Z.

At 06Z at KLAX, there was a surfaced based inversion up to 1500
feet with a maximum temperature of 21 degrees.

High confidence for TAFs, except moderate confidence for KLAX and
KLGB that may (10-20% chance) see brief MVFR conditions after
12Z.

KLAX...Moderate confidence in TAF. There is a slight (10%) chance
of MVFR conditions from 13Z to 16Z. East wind component of 4 to 8
kt possible until 12Z.

KBUR...High confidence in TAF.

&&

.MARINE...17/819 PM.

For the Outer Waters, moderate to high confidence in current
forecast. Small Craft Advisory (SCA) level winds are likely
through late tonight over the two northern zones. There is a 30-40
percent chance of SCA gusts over PZZ676 as well. Saturday there
is a 30-40% chance of SCA level winds, followed by lighter winds
through Sunday. An approaching cold front has a small chance of
producing SCA level southerly winds, along with a chance of
showers between Monday evening and Tuesday morning. Wednesday into
Wednesday night, increasing NW flow is forecast, with a good
chance of SCA level winds.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Through Tuesday, fairly high
confidence in winds and seas remaining below SCA levels, however
an approaching cold front will bring increasing southerly winds,
along with a chance for showers between Monday evening and Tuesday
morning. Increasing NW winds expected Wednesday and Wednesday
night, with SCA winds possible by the evening.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. From Point Mugu to Malibu there
is a a low chance (10%) of SCA gusts nearshore below any
canyons/passes Saturday morning. Saturday afternoon through
Tuesday, moderate to high confidence in winds and seas remaining
below SCA criteria for all southern Inner Waters. Winds will begin
to increase of Tuesday from the NW, with SCA speeds possible by
Wednesday afternoon or evening

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for
      zone 670. (See LAXMWWLOX).

&&

$$

PUBLIC...Phillips/MW
AVIATION...Schoenfeld
MARINE...Ciliberti
SYNOPSIS...MW/CC

weather.gov/losangeles

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