273 
FXUS66 KLOX 272321
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
421 PM PDT Sat Sep 27 2025

.SYNOPSIS...27/116 PM.

Cooler than normal conditions will persist through at least the
middle of next week with a deep marine layer and periods of 
drizzle. Showers and thunderstorms are possible this afternoon, 
mainly in the mountains, with light rain possible along the 
Central Coast around Tuesday.

&&

.SHORT TERM (TDY-TUE)...27/210 PM.

An upper low that has been drifting around California for the last
week is making one last stand before finally moving into Arizona
on Sunday. CAM's were right on target even a few days ago showing
a strong storm cell developing over the northwest Ventura
mountains near the Apache burn scar this afternoon. Also expecting
some showers and isolated storms over the LA mountains. With the
upper low over southeast California all the storms are moving from
northeast to southwest, and some of them may hold together well
enough to drop some showers across the coast and valleys. The most
likely locations would be near the Ventura/Santa Barbara County
line and eastern half of LA County. Showers and storms are
expected to taper off by around 9pm.

With the low moving into AZ Sunday and less instability and
moisture available the threat of showers and storms across the
mountains is much lower than today. 

Another deep marine layer is expected Sunday and Monday mornings,
likely between 3000 and 4000 feet again with the possibility of 
drizzle or light rain across coast, valleys, and lower coastal 
slopes. Temperatures will again be 6-12 degrees below normal with 
very slow, if any clearing of the stratus.

Later in the day Monday into Tuesday a trough along the West 
coast with an unseasonably cold 530dam low just west of the 
Pacific northwest coast will push onshore along the Central 
Coast. Models have scaled back from earlier solutions but there
are still quite a few indicating light rain amounts, mainly under
a tenth of an inch across northwest SLO County with the southern 
extent of any precip no farther than about Santa Ynez.

.LONG TERM (WED-SAT)...27/112 PM.

Dry conditions are expected Wednesday and likely through next 
weekend with slowly warming temperatures that should get back to
near normal by Friday or Saturday. The one caveat is there are a
small percentage of solutions from the GEFS that continue to show
some upper level vorticity from Nardo getting picked up from the 
advancing trough off northern California and reaching southern 
California on Thursday. That is accompanied by a small wedge of
increased moisture aloft. With most of the ensemble solutions 
keeping Nardo well west of the area there are currently no chances
for rain or storms locally, but it's worth keeping an eye on.

&&

.AVIATION...27/2320Z.

At 2330Z at KLAX, the marine layer was 3500 ft deep. The top of 
the inversion was around 4500 feet with a temperature of 16 C.

Overall, moderate confidence in 00Z TAF Package. Timing of flight
cat changes may be off by +/- 2 hours, and flight cats may be off
by one cat at times through the period. 

There is a 15-25% chance for isolated thunderstorms through this
evening at KSBA, KOXR, KCMA, KSMO, KLAX, KLGB, KBUR, and KVNY, 
with a 30 percent chance at KPMD and KWJF through 05z. Any 
thunderstorm can produce gusty erratic winds, frequent lightning, 
brief heavy rain, and small hail.

KLAX...Moderate confidence in 00Z TAF. There is a 20% chance for 
thunderstorms through 06Z Sun. Generally expecting MVFR CIGs 
015-030, with a likely chance of VFR conditions at times this 
afternoon. There is a 30% chance for an east wind component 
reaching 8 kts from 10Z to 18Z Sunday.

KBUR...Moderate confidence in 00Z TAF. Timing of flight cat 
changes may be off 2 hours. 20% chance for thunderstorms through 
06Z Sun. There is a 30% chance of IFR conditions from 08Z to 16Z 
Sunday.

&&

.MARINE...27/1123 AM.

Winds and seas are likely to remain below Small Craft Advisory 
(SCA) levels for all coastal waters through Wednesday. There is a 
30% chance of SCA wind developing Wednesday night for the central 
and southern outer waters as well as the western portions of the 
Santa Barbara Channel. Thereafter, chances for winds & seas to
reach SCA levels increases significantly - details will be ironed
out with future updates. 

There is a slight chance of Thunderstorms across the nearshore 
waters south of Point Conception through this evening. 
Any thunderstorms that develop would be capable of producing 
locally gusty winds and rough seas, dangerous lightning, heavy 
rainfall with reduced visibility and small hail.

Seas are expected to remain below SCA levels through at least
Tuesday. Sunday into early next week, a southerly swell of 4 to 6
feet will impact the coastal waters and may produce issues for 
exposed south facing harbors.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect from Sunday morning through
      Wednesday afternoon for zones 87-340-346-354-362-366. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...MW
AVIATION...Gomberg/Black
MARINE...Black/Schoenfeld
SYNOPSIS...MW/RK

weather.gov/losangeles

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