507
FXUS66 KLOX 070531
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1031 PM PDT Tue May 6 2025

Updated Aviation Section

.SYNOPSIS...06/1235 PM.

High pressure aloft will push in over California Wednesday through
Sunday, resulting in much warmer conditions, peaking Friday and
Saturday. Some coastal areas will remain mild under a shrinking
marine layer. Gusty north winds will for Thursday Night and
continue through at least the weekend.

&&

.SHORT TERM (TUE-FRI)...06/848 PM.

***UPDATE***

Latest satellite and surface observations indicated widespread
cloud cover south of Point Conception and lesser cloud cover
across the Central Coast. Current sounding data indicates marine
inversion ranging between 3000 and 4500 feet in depth.

Forecast-wise for the immediate short term, no significant issues
are expected. Cloud cover will likely increase overnight,
blanketing most of the area, up through the coastal slopes.
Additionally, there may be a stray sprinkle or brief light shower
just about anywhere overnight, but nothing of any significance.
Overnight, the gusty southwesterly winds across the desert
foothills and Antelope Valleys will diminish.

Overall, current forecast has good handle on the immediate short
term. So, no significant updates are anticipated.

***From Previous Discussion***

The low pressure system that has kept us cool and cloudy over the
past few days is now over New Mexico and will continue to move
further to the east. A weak disturbance will wobble around that
low tonight and approach our area, but any showers that may result
looks to stay east of Los Angeles County. In the 10% chance that
is tracks further to the west, the Antelope Valley and San Gabriel
Mountains would see a light shower or two tonight.

A significant warm up will commence on Wednesday, as high pressure
aloft currently to our west slides over California. This will
warm the airmass while weakening the onshore flow. As a result,
highs in the 70s will be common tomorrow with better (but not
complete) afternoon clearing. Thursday will warm up about 8
degrees, and Friday another 8 degrees on top of that with highs in
the mid 80s to mid 90s common. Temperatures will peak Friday and
Saturday, and with a range of outcomes around plus or minus 5
degrees, isolated triple digits in the warmest valleys are not
out of the question. With overnight lows also warming up in most
places, Heat Advisories in our warmest valleys are in play (50%
chance at this point) for Friday and Saturday. A couple of records
will be threatened as well. Coastal sections will be the hardest
to peg. Most of the model guidance wants to clear everything out.
That makes sense for coastal San Luis Obispo and Santa Barbara
Counties where offshore flow picks up starting Thursday Night.
Highs up there should range in the mid 80s to mid 90s especially
on Friday when a Central Coast Heat Advisory is not out of the
question. For Los Angeles and Ventura Counties however, any
offshore winds should stay up in the mountains. With that in mind,
an it being the infamous month of May Gray, it is hard to imagine
that the marine layer will completely dissipate. If that
assumption is correct, those coastal areas will warm but only a
little and there will be a sharp temperature gradient from the
mild beaches to the hot valleys. If the marine layer does scatter
out, expect coastal temperatures to be 5-10 degree above the
current forecast.

.LONG TERM (SAT-TUE)...06/205 PM.

See previous section on the Saturday details, with the next round
of heat peaking Friday and Saturday. The majority of guidances
show the heat-driving upper level high moving to the east Sunday
through Tuesday as a low pressure system drop down through the
western states. Temperatures now look to rapidly lower from
Saturday through Monday by 15-25 degrees. The marine layer should
also rapidly deepen in that time as well, with drizzle becoming
more and more possible. In addition to the drizzle, there is also
a small chance of actual light rain if the projections that sag
the low furthest to the south pans out. In addition, this looks
to be a windy period, with gusty northwest winds.

&&

.AVIATION...07/0530Z.

At 0441Z at KLAX, the marine layer was around 5000 ft deep. The
top of the inversion was around 6000 ft with a temperature of 10
C.

High confidence in TAFs for KPMD and KWJF.

Low confidence in TAF for KPRB. 30% chance for LIFR conds once
cigs arrive. There is also a 30% chance VFR conds prevail thru the
period.

Moderate confidence in remaining TAFs. Due to multiple cloud
decks, cigs 015-025 may vary between OVC and SCT at times, leading
to conds bouncing between MVFR and VFR, especially through 12Z.
There is a 40% chance for conds to remain MVFR or higher through
the period for KSMX/KSBP. Low confidence in clearing times (+/- 3
hours), but moderate confidence that most sites will at least SCT
after 18Z.

KLAX...Moderate confidence in TAF. Through at least 12Z, cigs
015-025 may vary between OVC and SCT due to multiple cloud decks.
Clearing time may be off +/- 2 hours, but moderate confidence in
cigs at least SCT after 18Z. No significant east wind component
expected.

KBUR...Moderate confidence in TAF. Clearing time may be off +/- 2
hrs.

&&

.MARINE...06/848 PM.

Conditions will remain relatively benign through Wednesday
morning. Wednesday afternoon/evening, there is potential for some
near SCA level winds for the inner waters south of Point
Conception. Lower confidence in this, but current thinking is
winds will be just below SCA levels. From Thursday afternoon into
the weekend, moderate to high confidence for widespread SCA level
winds across the Outer Waters. Winds may increase to SCA levels in
the Inner Waters along the Central Coast and the western half of
the Santa Barbara Channel, but confidence is low at this point.
Seas will begin to build near SCA levels for the Outer Waters this
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Kittell/Thompson
AVIATION...Lewis
MARINE...Phillips/Black
SYNOPSIS...RK

weather.gov/losangeles

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