950
FXUS66 KLOX 170355
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
855 PM PDT Mon Sep 16 2024

.SYNOPSIS...16/841 PM.

Much cooler than normal temperatures will continue through Friday
before warmer conditions return for the weekend. There is a
chance of rain or drizzle Wednesday night and Thursday as a low
pressure system moves into the area.

&&

.SHORT TERM (MON-THU)...16/854 PM.

***UPDATE***

Skies are relatively clear following the passage of the cold
front into the Great Basin. VBG and NKX soundings show a very weak
marine inversion that will struggle to support low cloud
development tonight, but there will be some warming aloft
eventually that could allow for some random patches of stratus, as
we`re seeing across parts of the Central Coast this evening.
Temperatures the next couple days will remain on the cooler side
but slowly warming as the upper low moves farther east and heights
slowly rise. Overall still 5-10 degrees below normal in most
areas and as much as 15 degrees below normal inland.

***From Previous Discussion***

Guidance has trended slower and further west with our second
early season storm to pass through the region Wednesday into
Thursday. This is a colder and somewhat wetter scenario with light
rain or drizzle possible just about anywhere in southwest
California at some point during this time frame. The cold core low
pressure system may be dynamic enough to support isolated
thunderstorms for interior Ventura, Santa Barbara, and San Luis
Obispo Counties sometime Thursday with the most likely window in
the afternoon. Rainfall amounts will generally be light and under
a quarter of an inch, although locally higher amounts are possible
for Santa Lucia mountains in northwest San Luis Obispo County and
the eastern foothills and lower mountains of Los Angeles County,
as well as in any thunderstorms that do form. Breezy northwest to
onshore winds are likely Wednesday into Thursday with the most
wind prone areas potentially reaching advisory levels.

.LONG TERM (FRI-MON)...16/242 PM.

Moderate forecast confidence for the upcoming weekend with two
main scenarios in play.

Most likely scenario (80% chance): Significant warming and drying
this weekend, with temperatures reaching the 90s to around 100
for many inland areas. Generally light offshore breezes will be
possible each morning. This would likely increase fire weather
concerns.

Less likely scenario (20% chance): The warming trend is less
intense, with highs mostly in the 70s and 80s. Low clouds and fog
may linger along the coast, especially the Central and LA coasts.

Regardless of the weekend scenario: Next week is likely to be
warmer than normal, suggesting a prolonged period of above-normal
temperatures may begin as early as this weekend.

&&

.AVIATION...17/0134Z.

At 00Z at KLAX, there was a moist layer up to 6000 feet deep.
There was no inversion.

High confidence for TAFs at KPMD and KWJF.

Low-moderate confidence in all remaining TAFs. Sites south of
point conception will likely have cigs between 020 and 050 when
cigs return later tonight thru tomorrow. There is a chance for
LIFR cigs/vsbys at KSMX (30%) and KSBP (10%) between 10Z and 16Z.
There is a 20% chance for IFR-MVFR cigs at KPRB from 10Z to 15Z.
Minimum flight cats may bounce frequently during the period at all
sites. Arrival time of cigs may be off +/- 3 hours from current
forecast.

KLAX...Moderate confidence in TAF. Cigs will likely vary between
BKN020 and BKN040 thru 18Z tomorrow. Cigs expected by 07Z. Cigs >
BKN035 could arrive as early as 13Z. No significant east wind
component expected.

KBUR...Low to moderate confidence in TAF. Cigs will likely vary
between BKN020 and BKN040 through 17Z. Arrival and dissipation of
cigs may be off by +/- 3 hours from TAF.

&&

.MARINE...16/209 PM.

For the Outer Waters (Central Coast to San Nicolas Island),
moderate to high confidence in the forecast. For the northern zone
(Pt Piedras Blancas to Pt Sal) winds are likely to remain below
SCA level until Tues afternoon, then there is a 60-80% chance of
SCA level winds developing Tues afternoon thru Wed morning. From
Wed afternoon thru late Sun, moderate confidence in winds
remaining below SCA level, with a 30-50% chance of SCA winds Fri
thru Sun, with best chances Sun. For the southern zones (Pt Sal
to San Nicolas Island) moderate to high confidence in SCA level
winds persisting into early Wednesday, with a lull possible
Tuesday morning. There is a 40-60% chance of SCA winds continuing
thru late Wed. There is a 30-60% chance of SCA level winds Thurs
thru Sun, with best chances Fri afternoon thru late night.

For the Inner Waters off the Central Coast. High confidence winds
will remain sub advisory level thru tomorrow morning, then there
is a 60-80% chance of SCA winds in the afternoon thru evening
hours Tues. Moderate confidence in winds being sub advisory Wed
thru Sunday, with lowest confidence in the afternoon thru evening
hours Fri thru Sun.

For the Santa Barbara Channel, high confidence in Gale Force
thru late tonight, then rapidly decreasing to below SCA level.
Steep, choppy seas and strong rip currents can be expected thru
late tonight. There is a 40-70% chance in SCA level winds
returning Tues and Wed afternoon thru late night, with higher
confidence Tues. From Thurs to Sun, There is a 20-50% chance of
SCA level winds in the afternoon thru evening hours, with highest
confidence Fri.

For the nearshore waters off the Los Angeles and Orange County
coasts, SCA level winds will continue throughout much of the
zone. In the northwest portion of the zone from Malibu west to the
Channel Islands and as far south as Santa Barbara Island, high
confidence in Gales thru late tonight. Seas will be choppy in
this area, and exposed beaches may see strong rip currents. Winds
will quickly drop off to below SCA levels overnight into early
Tues. Moderate to high confidence in winds remaining below SCA
level Tues afternoon thru Sun.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 3 AM PDT Tuesday for
      zones 354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect from 3 PM Tuesday to 3 AM PDT
      Wednesday for zones 645-650-670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Tuesday for zones
      650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Munroe
AVIATION...JB
MARINE...Lewis
SYNOPSIS...MW

weather.gov/losangeles

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