Montrose, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

308
FXUS66 KLOX 240325
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
825 PM PDT Fri May 23 2025

.SYNOPSIS...23/746 PM.

Temperatures will fall each day through Saturday, with increasing
low clouds and fog. Sunday through mid next week, temperatures
will be slightly below normal for most areas and marine layer low
clouds and fog will continue during the night to morning hours.

&&

.SHORT TERM (FRI-MON)...23/824 PM.

Additional cooling took place today across much of the region due
to an approaching upper level trough of low pressure and
strengthening onshore flow near the surface (LAX-DAG pressure
gradient peaking over +8 mb). The warmest valley and desert
locations only climbed into the lower to mid 80s today. For
tonight the upper level trough will evolve into an upper level low
pressure system which combined with an associated vort max will
likely bring significant deepening of the marine layer, especially
across LA county. Current satellite imagery showing an organized
band of mid to high level clouds streaming over the area in
association with this weak upper level system, as well as some
patchy low clouds developing across portions of the coast.

Current ACARS data indicates the marine layer depth across the
LA Basin to be around 2000 feet. Rapid deepening of the marine
layer is expected overnight into Saturday morning due to lower
heights and lift associated with upper level low pressure
system, strengthening onshore flow, and developing eddy
circulation. By late tonight or early Saturday morning,
expecting marine layer depth to be at least 3000 feet across
the LA Basin. In evening update, will extend low clouds further
inland into the Santa Clarita Valley and nearby lower coastal
slopes/foothills. Will also add some patchy drizzle for late
tonight/Saturday morning, mainly focused on LA county. Looking
for some additional colling on Saturday, with the potential
for some low clouds lingering across immediate coastal areas
on Saturday afternoon, especially the Ventura county coast.

Other short term concern will be gusty onshore winds across the
interior, especially the Antelope Valley and adjacent foothills
where gusts of 35 to 45 mph have been common today. Also seeing
some gusty northwest winds across southwest Santa Barbara county.
Looking for similar gusty onshore winds on Saturday across the
interior.

***From previous discussion ***

A few degrees of warming is likely on Sunday, mainly inland as
the trough is replaced by a quick little pop up ridge. Onshore
flow remains quite strong though so cool air off the ocean will
keep areas closer to the coast on the cooler side.

Then Monday another weak upper low arrives which will bring cooler
temps and longer lasting marine layer to coast and valleys.
a

.LONG TERM (TUE-FRI)...23/1238 PM.

For most of next week just very minor day to day changes in
temperatures with a steady dose of night and morning low clouds
and fog for coast and valleys. Overall very typical weather for
this time of year except highs a few degrees cooler than normal.

There remains the potential for a significant warming trend late
next week into early June, as some forecast models show a
moderately strong high pressure system building over the Arizona-
Nevada region. The presence of a slowly moving cut off low may
keep this a low confidence forecast well into next week.

&&

.AVIATION...24/0008Z.

At 2355Z at KLAX, the marine layer was 2000 feet deep. The top of
the inversion was around 2500 feet with a temperature of 15 C.

High confidence in TAFs for KPMD and KWJF.

Fairly high probability in MVFR cigs reaching KLAX, KLGB, KSMO,
KBUR, and KVNY as marine layer deepens over LA county, but
timing of onset could be +/- 2 hours from what is currently
indicated in TAFs. For KOXR and KCMA, there is a 60% chance of
MVFR cigs developing later tonight, but only 30% chance of
reaching KSBA. There is also a 30-40% chance of IFR cigs
at KSBP and KSMX overnight. Some MVFR cigs could linger
into Saturday afternoon across immediate coastal areas,
especially Ventura County.

KLAX...SCT-BKN015-020 conditions through early evening. Then
moderate to high confidence in 00Z TAF. High confidence for MVFR
cigs to develop overnight but only moderate confidence in timing
which could be +/- 2 hours from current TAF forecast. Increased
confidence in east wind component reaching 7-8 knots from 08z-17z
Saturday, with a 20% chance of reaching 10 knots.

KBUR...Moderate to high confidence in 00Z TAF. High confidence
in MVFR cigs reaching KBUR late tonight into early Saturday
morning, with a 20% chance of IFR conditions. Moderate confidence
in timing of cigs, which could be +/- 2 hours from current
TAF.

&&

.MARINE...23/745 PM.

For the Outer Waters, high confidence in Small Craft Advisory
(SCA) level winds through Memorial Day weekend. GALE force wind
gusts are likely (50-60% chance) for NE portions of PZZ670, and
across the waters around and near Point Conception and Northern
Channel Islands (NCI) - this afternoon and evening. GALES may
linger into the late night hours around the NCI. In general, seas
are expected to remain below SCA criteria through mid-week -
however, there could be localized SCA level seas at times.

For the northern Inner Waters, SCA winds are expected to continue
through late tonight. Over Memorial Day weekend, moderate (40-60%
chance) confidence in SCA winds each afternoon through evening.
Seas are expected to remain below SCA levels through mid-week.

For the Santa Barbara Channel, SCA winds will likely reach
eastern portions of the zone including the Ventura County
coastline. There is a 40% chance of SCA level winds across the
western portion of the Channel each afternoon and evening over the
remainder of Memorial Day Weekend - Also, there is a 20% chance
for eastern portions, with Sat and Mon having the best potential.
Seas are expected to remain below SCA level through Mid-week.

For the Inner Waters off the Los Angeles and Orange County coasts,
moderate confidence in conditions remaining below advisory levels
this weekend. However, there is a 20-40% chance for local gusts
up to 25 kt to occur each afternoon through evening today through
Monday near Malibu, through the San Pedro Channel, and in the far
western portion of the zone, with the highest chances today.
Seas are expected to remain below SCA level through Mid- week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT Saturday for zones
      349-351. (See LAXNPWLOX).
     Beach Hazards Statement in effect from Saturday morning
      through late Monday night for zones 354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for
      zones 645-650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Saturday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/MW
AVIATION...Gomberg
MARINE...Ciliberti
SYNOPSIS...Schoenfeld/Ciliberti

weather.gov/losangeles

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