989
FXUS66 KLOX 260328
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
828 PM PDT Wed Sep 25 2024

.SYNOPSIS...25/112 PM.

Low clouds and fog will continue across coastal and valley areas
through the weekend with clearing to the beaches and below normal
temperatures. Far interior areas will remain above normal.
Otherwise, the quiet weather pattern will continue.

&&

.SHORT TERM (WED-SAT)...25/129 PM.

Cooler than normal temperatures are expected to continue through
the weekend for coast and valleys as a trough lingers along the
West Coast. Latest ensemble based guidance indicates an 80-90%
probability of valley temperatures under 95 through Sunday and
lower than 85 for Downtown LA. Deterministic models do indicate
some weakening of the onshore flow the next couple days which may
lead to slightly earlier clearing of low clouds in the valleys
but overall the cooler pattern will continue.

Farther inland from the mountains to the Kern County line
temperatures will remain above normal by 4 to 8 degrees. Winds
will be generally on the lighter side with those weakening
gradients. Otherwise, the very quiet and June-like conditions will
continue.

.LONG TERM (SUN-WED)...25/141 PM.

Looks like a return to above normal temperatures is likely
starting Monday as the weak upper low shifts west in response to
building high pressure from the east. Although there are still
some cooler ensemble solutions, the vast majority are showing the
warmer pattern and weakening onshore flow. In fact, roughly 10%
of the solutions show a low grade Santa Ana event with some
northeast winds across the interior. The deterministic GFS shows
significant warming at lower levels starting Monday with 950mb
temps jumping above 30c both Monday and Tuesday and 500mb heights
close to 595dam. 90th percentile temperatures, considered a
reasonable worst case scenario, get close to 110 in the warmer
valleys Tuesday and mid to high 90s for Downtown LA and other
inland coastal areas, including the Central Coast. Some cooling
is expected Wednesday but above normal temperatures will likely
last through next Thursday.

&&

.AVIATION...26/0327Z.

At 0006Z over KLAX, the marine layer was 1300 ft deep. The top of
the inversion was 2000 ft with a temperature of 24 Celsius.

High confidence in 00Z desert TAFs. Cigs due to marine layer
clouds leads to moderate to low confidence in remaining TAFs.
Could see cigs delayed 1-4 hours from the forecast arrival times.
Cigs may be slow to clear for KSMO, KLAX, and KLGB. Moderate to
high confidence in ceilings.

KLAX... Moderate to low confidence in 00Z TAF. Cigs may arrive 1-4
hours later than forecast. LIFR conditions may be delayed as well
by 1-3 hours. High confidence in no significant east wind
component.

KBUR...Good confidence cigs will return but low confidence in
timing. There is a 30% chance of VLIFR fog 11-15Z.

&&

.MARINE...25/1256 PM.

Moderate confidence in low-end Small Craft Advisory (SCA)
conditions forming over the waters south of Point Sal this
afternoon and evening, including the nearshore waters from
Ventura to Orange County. High confidence that these SCA winds
will return to their traditional areas (offshore waters from the
Central Coast to San Nicolas Island) for Thursday afternoon and
Night. High confidence in fairly light winds staying below SCA
levels Friday morning through Saturday morning. Moderate
confidence in SCA winds returning Saturday or Sunday and
persisting through Monday before another weakening period returns
Tuesday and Wednesday.

Dense fog with visibilities under 1 mile will continue to be a
concern through at least Friday, with the highest chances each
night and morning and along the Central Coast. Please refer to
the marine weather statement for more information.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Phillips
MARINE...RK
SYNOPSIS...MW

weather.gov/losangeles

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