742
FXUS66 KLOX 230417
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
817 PM PST Fri Nov 22 2024

.SYNOPSIS...22/725 PM.

Rain chances will develop along the Central Coast this evening,
then spread across Los Angeles and Ventura Counties by Saturday.
Light rain is expected at times tonight through Saturday, with
generally minimal accumulations. Periods of rain expected Sunday
through Tuesday, especially north of Point Conception.

&&

.SHORT TERM (FRI-MON)...22/816 PM.

***UPDATE***

A cold front extending from northern California to the coastal
waters off the Central Coast has an associated rain band that has
been slowly approaching San Luis Obispo County this afternoon and
evening. Rain should begin to spread over the NW Central Coast
area within the next couple of hours (between 900 to 1100 PM)
spreading southwestward across San Luis and Santa Barbara Counties
overnight, and then across Ventura and LA Counties on Saturday.
Gusty southerly winds will accompany the front, with gusts
generally between 20 to 35 mph across the windiest areas,
including the mountains and foothills. North of Pt. Conception the
stronger winds are expected this evening through tonight, then
shifting to areas further south on Saturday, mainly affecting the
mountains and Antelope Valley.

Rainfall totals for tonight through Saturday will be light over LA
County, up to 0.10 inch. For Ventura and Santa Barbara Counties,
totals will be 0.10 to 0.25, with 0.20 to 1.0 inch over San Luis
Obispo County, except for potentially up to 1.5 inches in the
Santa Lucias.

***From Previous Discussion***

The large cyclone off the Pac NW coast has split into two which
are pinwheeling around each other. The southern extent of the
moisture is around Monterey, but that will be sagging south
tonight and through early next week as the main upper low shifts
south to near the OR/CA border. With the upper low remaining that
far north that will limit the impacts and rainfall amounts
locally.

Latest ensembles and hi res models all indicating 3-5 hours of
very light amounts with this first impulse, mostly under a quarter
inch most areas. Locally up to a half inch in the upslope areas
of SLO/SB Counties. For LA County light rain expected to start mid
to late morning with most areas under a tenth of an inch and many
areas may not receive more than a trace.

After that there`s a roughly 24-36 hour break before the second
impulse comes through Sunday (for SLO County) and later Sunday
into Monday south of there. The 12z ENS solutions definitely
ticked up across SLO County, with the precip means between now
between 1 and 1.5 inches. Which means upslope areas in the Santa
Lucias could be looking at around 3" or rain with with this
impulse through Tuesday. The GEFS means remain well under an inch
in all areas so still some uncertainty there. Even with these
slightly higher numbers the chances for any significant flooding
issues remains under 10%.

Amounts drop off quite a bit to the south, and especially south of
Santa Barbara with totals through Tuesday still under 1 inch and
likely under a half inch for most of LA County. No snow and wind
issues expected, though it will be breezy at times, mainly at the
higher elevations.

.LONG TERM (TUE-FRI)...22/155 PM.

Still a possibility of some lingering light showers Wednesday but
the ensembles have basically gone back to a dry pattern the
remainder of the week and through the Thanksgiving weekend. There
are some indications of increasing offshore flow but so far the
ENS ensembles are mostly on the weak to moderate side, which
matches up well with the deterministic LAX-DAG gradients which
are between -4 and -5.5mb while the GFS gradients are weaker.
Temperatures will be on a steady but slow climb each day but
generally remaining slightly below normal through Friday.

&&

.AVIATION...23/0016Z.

At 23Z at KLAX, there was no marine layer. There was a surface
based inversion with a top at 1400 ft with a temperature of 19 C.

Moderate to high confidence in the TAFs. Cig/vsby restrictions and
light rain are forecast to spread southward across areas north of
Pt. Conception this evening. Light rain coverage will be less as
the activity spreads farther south tonight, though MVFR cigs are
still expected south of Pt. Conception tonight into Saturday.
Onset times of cig/vsby restrictions may vary by +/- 3 hours from
current forecasts. Minimum cigs/vsbys could be off by a category
or two. The light rain will be departing the region later on
Saturday, when cigs/vsbys improve.

KLAX...High confidence in VFR conditions through this evening.
MVFR cigs are expected thereafter. There is a 40% chance for
onset times of cig restrictions to vary by +/- 3 hours from
current forecasts, and a 40% chance for minimum cigs to be off by
a category. There is a 20% chance for light rain to impact the
TAF site tonight into Saturday morning. There is a 40% chance for
winds to become easterly and exceed 8 kt Saturday 12Z-21Z.

KBUR...High confidence in VFR conditions through this evening.
MVFR cigs are expected thereafter. There is a 40% chance for
onset times of cig restrictions to vary by +/- 3 hours from
current forecasts, and a 40% chance for minimum cigs to be off by
a category. There is a 25% chance for light rain to impact the
TAF site tonight into Saturday morning.

&&

.MARINE...22/804 PM.

For the Outer Waters, moderate to high confidence in current
forecast. Small Craft Advisory (SCA) winds will persist through
tonight. Borderline SCA level seas are possible for western
portions of PZZ670/673. Otherwise, SCA conditions are unlikely
through Tuesday.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. SCA level winds will persist
through tonight. Otherwise, high confidence in winds and seas
remaining below SCA levels through Tuesday.

For the Inner Waters south of Point Conception, high confidence in
winds and seas remaining below SCA levels through Tuesday.

For all coastal waters, expect areas of light rain to occur at
times through next week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 6 AM PST Saturday for zones
      340-344. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Saturday for
      zones 645-670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Smith
AVIATION...Cohen/Black
MARINE...Black
SYNOPSIS...MW/Smith

weather.gov/losangeles

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