199
FXUS66 KLOX 092125
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
225 PM PDT Sun Mar 9 2025

.SYNOPSIS...09/134 PM.

One more sunny day Monday with above normal temperatures before a
series of storms brings periods of rain, mountain snow, and much
colder temperatures through the week.

&&

.SHORT TERM (TDY-WED)...09/211 PM.

No significant deviations to the forecast today. A little cooling
Monday but still above normal temperatures away from the
immediate coast which will cool slightly with an increase in
onshore flow.

The center of the first low pressure system is now targeted for
northern Baja, but there is still enough wrap around moisture to
generate some light showers late Monday night into Tuesday south
of Pt Conception. Rain amounts expected to be a quarter inch or
less, except up to a half inch across extreme southern LA County,
including Catalina Island.

Not much of a break now between the first system Tuesday and the
much stronger second system Wednesday. Will likely see some light
to moderate warm frontal rains developing as early as Wednesday
morning, but models have remained consistent showing the strongest
part of the storm coming through Wednesday night into early
Thursday. Still looking like roughly 75% of the total rain from
this system falling during that peak period. The only minor
adjustment noted in the models today was the low and mid level
southerly jets are not as strong as previous solutions, which if
this holds then the upslope component to the rain amounts wouldn`t
be quite as significant. However, PW`s continue to climb, now very
close to 1" during the peak of the storm, which is solidly above
the 90th percentile, and rain totals were nudged to that
percentile as well, namely 1-2" for coast/valleys and 2-4 inches
mountains. Rain rates during that period could exceed a half inch
per hour, potentially causing at least some shallow debris flows
in the recent burn areas. Those chances would increase if
thunderstorms develop, which is possible late Wednesday night
into Thursday given the 75th percentile ensemble CAPE values close
to 500j/kg.

With that little warm front coming in Wednesday, snow levels were
nudged a little higher in the models today for the peak part of
the storm through early Thursday to between 6000 and 7000 feet,
but much colder air will quickly move in Thursday with snow levels
crashing to around 3000 feet. It will be a more showery pattern at
that point with moderate west to northwest flow aloft but it`s a
favorable set up for at least some light accumulating snow across
places that don`t often see snow, including the San Lucias, the
Santa Ynez Range, and possibly even the Santa Monicas. Travel
through the Grapevine on Interstate 5 will likely see snow
accumulations as well.

.LONG TERM (THU-SUN)...09/224 PM.

A cool and moist northwest flow continues through the weekend so
some showers can`t be ruled out, especially north of Pt Conception
and in the mountains. The west/east oriented Transverse range
will provide a bit of rain shadow for southern areas but certainly
can`t rule out a shower just about anywhere with snow levels
around 5000. There`s very little energy associated pattern so
rain rates are expected to be a quarter inch or less with few
impacts.

&&

.AVIATION...09/1846Z.

Around 12Z, there was no marine layer depth at KLAX.

Low confidence in coastal TAFs, especially after 06Z, with high
confidence elsewhere. There is a 20 percent chance of IFR cigs by
03Z for KOXR, KCMA, and KSBA. There is a 40-50 percent chance
that IFR or lower cigs occur where not forecasted and vice versa
with the most likely window between 09-18Z. Flight category may
be off by one and timing of cigs by 3+ hours.

KLAX...High confidence in forecast through 06Z and low confidence
between 10-18Z with a 40 percent chance that VFR conds prevail.
Any easterly winds will be less than 7 knots.

KBUR....VFR conditions are expected through the period. No wind
impacts are expected at this time.

&&

.MARINE...09/155 PM.

Winds and seas will remain below Small Craft Advisory (SCA)
levels through late Wednesday, except for a 20-40 percent chance
for periods of SCA level winds Monday afternoon through Tuesday
for the waters southwest through northwest of the Channel Islands
and the waters beyond 30 NM of the Central Coast, with highest
chances in the Outer Waters. Between Wednesday afternoon and
Wednesday night, there is an increasing chance for widespread SCA
conditions as a storm system approaches the waters. There is a
60-80% chance for widespread SCA conditions by late Wednesday
night and continuing through at least the end of the week. There
is a moderate (30-50 percent) chance of Gale force winds Thursday.

There is a 10-20 percent chance of thunderstorms late Wednesday
into Thursday with heavy rain, gusty winds, steep seas, small
hail, and waterspouts possible.

Active weather pattern may continue at times through at least
early next week.

&&

.BEACHES...09/343 AM.

There is a 40-60 percent chance of high surf developing at all
beaches between Wednesday night and Thursday as a strong storm
system originating out of the Gulf of Alaska moves over the
region. There is a high (60-80 percent) chance of strong rip
currents and elevated surf during this period. Surf should
diminish at southern beaches between Friday and Saturday, but
there is a moderate chance that at least elevated surf could
linger next weekend at Central Coast beaches.

&&

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

&&

$$

PUBLIC...MW
AVIATION...Munroe
MARINE...Munroe/Hall
BEACHES...Hall
SYNOPSIS...MW

weather.gov/losangeles

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