759
FXUS66 KLOX 221136
AFDLOX

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

.SYNOPSIS...22/245 AM.

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. Another round of rain is
expected later Sunday into Monday.

&&

.SHORT TERM (TDY-SUN)...22/314 AM.

Cold overnight temperatures will persist into this morning for
interior wind- sheltered valleys, including the Ojai Valley and
Calabasas/Agoura Hills region, where a Frost Advisory is in effect
until 8 AM. Additionally, patchy dense fog is also possible for
some coastal areas, particularly for the Ventura County beaches.

The strong low pressure system continues to rotate just off the
coast of the Pacific Northwest, and this pattern is expected to
continue trough at least Monday night. Today into tonight, a
trough associated with the upper low will sweep into California,
bringing the southernmost portion of a very large scale rain band
(also has been referred to as an atmospheric river) into Southwest
California.

The frontal system will bring rain chances starting this evening
(late tonight for LA County), with rain possible tonight through
Saturday. Several hours of light stratiform rain (generally well
under 0.25 inch per hour) is expected during the period of
heaviest rainfall. Rain will be the heaviest tonight for the
Central Coast, Saturday morning for Santa Barbara City and Ventura
county, and Saturday mid-day for LA County. Rain totals have
slightly trended up with the latest model data, however are still
not expected to be especially impactful. San Luis Obispo and Santa
Barbara Counties are likely to see about 0.3 to 0.7 inches of
rain, expect for up to 1.5 inches for the Santa Lucia Range.
Ventura and LA Counties are largely expected to see 0.3 inches of
rain or less. The main hazards with this rain will be slick roads
and periods of reduced visibilities.

Gusty south winds will also occur this evening through tonight
for much of San Luis Obispo and Santa Barbara County. Wind
Advisories have been issued for the San Luis Obispo County Beaches
and far interior valleys starting at 8 pm tonight.

Saturday night and Sunday slight chances of showers linger for
the region, however dry conditions are overall expected south of
Point Conception through Sunday afternoon. For the Central Coast,
the next rain band from the PacNW low pressure system will arrive
as early as Sunday morning. Rain chances will extend southward,
reaching LA County by Sunday night.

.LONG TERM (MON-THU)...22/331 AM.

A second and longer lasting rain event is expected to start
during the day Sunday for the Central Coast and Sunday night
elsewhere (including LA County). On-and-off rain and wet
conditions will persist through Tuesday, driven by zonal upper
level flow over the region. There remains some uncertainty in
rain totals, however confidence is increasing for moderate rain
totals (1 to 2 inches, up to 4 in the mountains) for San Luis
Obispo and Santa Barbara Counties, and low totals (1 to 2 inches)
for Ventura and LA Counties. Some southerly flow at the lower
levels with this storm will enhance rain totals for south- facing
slopes. Thus, certain favored areas, such as NW San Luis Obispo
County and the Santa Barbara South Coast, may see higher totals up
to 2 inches, and peak rain rates approaching 0.33 inch per hour.
Even with this enhancement, this is still well below any flooding
impact thresholds. Rain totals of under an inch are expected for
the majority of low level locations.

However, as the forecast evolves, the risk and hazards associated
with this system may increase somewhat, with around a 10-20%
chance of a more impactful rain totals.

There remains a slight chance (10-20%) of rain on Thanksgiving
for the Central Coast, with dry conditions expected elsewhere.

&&

.AVIATION...22/1136Z.

At 1100Z at KLAX, there was a surface-based inversion with a top
at 2100 ft and a temperature of 19 degrees Celsius.

Overall, moderate confidence in 12Z TAF package. For coastal
sites this morning, there is a 30% chance that CIG/VSBY
restrictions do not develop at KSMX/KSBP and a 30-40% chance of
CIG/VSBY restrictions for KSBA/KOXR/KCMA/KSMO/KLAX/KLGB.

For tonight, light rain will move into the area. Chances for light
rain will be confined from KSBA northward after 02Z.

KLAX...Moderate confidence in 12Z TAF. There is a 40% chance of
IFR/LIFR CIGs and VSBYs 12Z-18Z. For this evening and overnight,
high confidence in return of MVFR conditions, but low confidence
in timing (could be +/- 4 hours of current forecasts). There is a
chance of light rain after 13Z. No significant easterly wind
component is expected.

KBUR...Overall, moderate confidence in 12Z TAF. High confidence in
VFR conditions through this evening. For tonight, high confidence
in return of MVFR conditions, but low confidence in timing (could
be +/- 4 hours of current forecast).

&&

.MARINE...22/113 AM.

For the Outer Waters, moderate to high confidence in current
forecast. Today through tonight, there is a 50-70% chance of Small
Craft Advisory (SCA) level winds across PZZ670/673. For Saturday
through Tuesday, high confidence in winds and seas remaining below
SCA levels for all the Outer Waters.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. For tonight, there is a 50% chance
of SCA level winds. For Saturday through Tuesday, high confidence
in winds and seas remaining below SCA levels.

For the Inner Waters south of Point Conception, high confidence in
current forecast. Today through Tuesday, winds and seas are
expected to remain below SCA levels.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 8 PM this evening to 6 AM PST
      Saturday for zones 340-344. (See LAXNPWLOX).
     Frost Advisory remains in effect until 8 AM PST this morning
      for zones 357-371. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 8 PM this evening to 3 AM
      PST Saturday for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 9 AM this morning to 3 AM
      PST Saturday for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PST Saturday for zone 673. (See LAXMWWLOX).

&&

$$

PUBLIC...Schoenfeld
AVIATION...RAT
MARINE...RAT
SYNOPSIS...MW/Smith/Schoenfeld

weather.gov/losangeles

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