Sierra Madre, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

209
FXUS66 KLOX 280350
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
850 PM PDT Tue May 27 2025

.SYNOPSIS...27/749 PM.

A warming trend will occur through the week, with above normal
temperatures Thursday through Saturday. The heat will peak on
Friday, with highs near or above 100 degrees for the deserts and
warmest valleys. Marine layer low clouds and fog will affect the
coast and some valleys each night and morning, becoming shallow
and confined to the coastal plains Friday and Saturday.

&&

.SHORT TERM (TUE-FRI)...27/813 PM.

***UPDATE***

The main forecast issue for the overnight period will be stratus
coverage, with low clouds expected to once again move inland over
most of the coast and all the coastal valleys. Onshore pressure
gradients are slightly stronger than yesterday`s, with the LAX to
Daggett gradient around +7 mb. There is a 30 percent chance that
scattered low clouds make it into the Santa Clarita Valley early
Wednesday morning. Onshore winds this evening are moderate, with
gusts 20 to 30 mph through the interior passes and canyons, and
close to 40 mph near Lake Palmdale. The winds will decrease late
this evening, and become light after midnight for most areas.

On Wednesday a weak low pressure system will move over the area
producing some high clouds, and possibly delaying clearing of the
marine layer clouds into the afternoon hours. Temperatures will
be similar to today, or up a degree or two with highs ranging from
60s to near 70 along the coast to 80s inland, and low 90s in the
Antelope Valley.

***From Previous Discussion***

Very little change expected Wednesday as another weak upper low
approaches from the west and likely keeps the marine layer on the
deeper side. This morning cloud top reports were between 2500 and
3000 feet and forecast soundings are indicating little change in
that while onshore flow is similar to today. Thus, expecting
another round of morning stratus for all the coast and coastal
valleys and temperatures within 1-3 degrees of today and also
withing 1-3 degrees of normal.

A warming trend will begin in earnest Thursday and peak Friday.
The one big caveat being the upper low which cuts off and
lingers just south of the border through the weekend and perhaps
into next week according to some ensemble solutions. Given that
models are pretty consistent with the track, there is higher
confidence that temperatures will heat up significantly north of
Pt Conception, and particularly inland SLO County where chances of
needing heat advisories are around 70-80%. The record high Friday
in Paso Robles is 102 and highs are expected to be right around
that number. Virtually all the ensemble models show highs at or
above 100 there Friday and some as high as 106. Farther south the
upper low may keep temperatures down just enough to hold off on
advisories but more time is needed to see how the pattern evolves.
In any case, it will be a warm or hot ending to the week away
from the immediate coast.

.LONG TERM (SAT-TUE)...27/204 PM.

Onshore flow is expected to begin increasing Saturday which will
lead to some cooling across the area, but how much cooling is
still uncertain. There may be some mid and high level moisture
rotating around the low from the east that could mitigate the heat
somewhat.

Sunday through Monday, the cutoff low is favored to move west
over land just south of the region. This would bring southerly
flow, moisture, and instability to the area, along with a
significant drop in temperatures, especially on Monday when highs
are likely to be several degrees below normal. Currently there is
around a 10 to 20 percent chance of showers or thunderstorms
Saturday afternoon through early Monday, focused south of Point
Conception. The greatest chance of convection will be over the
mountains of LA and Ventura Counties. Looking ahead further into
next week, some model projections hint at an unseasonably cold
pattern with more chances for precipitation.

&&

.AVIATION...28/0225Z.

Around 2219Z, the marine layer depth was around 800 feet deep at
KLAX. The top of the inversion was around 5600 feet with a
temperature of 16 degrees Celsius.

Moderate confidence in the current forecast for coastal and valley
terminals. High confidence in the current forecast for desert
terminals.

LIFR conditions are likely for terminals north of Point
Conception between 10Z and 13Z. There is a moderate chance of IFR
conditions in drizzle at Los Angeles County terminals between 13Z
and 16Z. Lower confidence in clearing times, as cigs could persist
into the afternoon.

KLAX...MVFR conditions will spread into KLAX as early as 01Z, or
as late as 08Z. There is a 40 percent chance of IFR conditions in
drizzle between 13Z and 16Z. VFR conditions could as early as 17Z
Wednesday. East wind component should remain below 6 kt.

KBUR...VFR conditions are expected through at least 06Z. Lower
confidence in timing. MVFR conditions will spread into KLAX as
early as 06Z, or as late as 13Z. There is a 30 percent chance of
IFR conditions in drizzle between 13Z and 16Z.

&&

.MARINE...27/844 PM.

For the outer waters moderate to high confidence that Small Craft
Advisory (SCA) level winds will continue through late tonight,
with a lull of several hours early Wednesday morning. There is a
60-80 percent chance of SCA conditions Wednesday afternoon
through Friday. There is a 40 percent chance of GALES Wednesday
night through Thursday night, mainly from the Channel Islands and
northward. Conditions should be below SCA levels Friday through
Saturday, but confidence is growing for SCA level winds Saturday
night through Tuesday.

For the nearshore waters along the Central Coast, there is a
50-60 percent chance of Small Craft Advisory (SCA) level winds
Wednesday afternoon and evening, then there is a likely (60-80
percent) chance of SCA level winds Thursday afternoon and evening.
Conditions should be below SCA levels Friday through Sunday, but
confidence is growing for SCA level winds Sunday night through
Tuesday.

For the Santa Barbara Channel, moderate confidence in SCA winds
through late tonight over the western portion, and a 40% chance
of SCA level winds again Wednesday afternoon and evening. Moderate
confidence in conditions remaining below SCA levels for Friday
through Sunday.

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

&&

.BEACHES...27/1118 AM.

A long period south swell, that brought elevated surf conditions
and a high risk for hazardous rip currents over the weekend, will
continue to subside through late tonight.

Another long period south swell will bring another round of
elevated surf up to 6 feet and strong and hazardous rip currents
over the upcoming weekend. Confidence is moderately high in the
timing between Sunday through Tuesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 3 AM PDT Wednesday
      for zones 349-350-354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Ciliberti
AVIATION...Phillips
MARINE...Ciliberti
BEACHES...Hall
SYNOPSIS...Schoenfeld/Ciliberti

weather.gov/losangeles

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