751
FXUS66 KLOX 120544
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
944 PM PST Tue Nov 11 2025

.SYNOPSIS...11/652 PM.

Onshore flow and increasing clouds will bring significant cooling
to inland areas tomorrow A shallow marine layer will create dense
fog at times at the coast tonight, with low clouds moving into
the valleys by Wednesday morning. At the same time, high clouds
will increase as a storm system approaches the West Coast. Rain is
expected to spread over the area Wednesday night through Thursday
night or Friday, and possibly into Saturday.

&&

.SHORT TERM (TUE-FRI)...11/753 PM.

***UPDATE***

The large scale pattern shows an upper closed low about 1100 miles
west of Los Angeles, forecast to merge with a large upper trough
approaching from the northwest. As this feature moves closer to
the coast, heights aloft will decrease and onshore flow will
increase, continuing a significant cooling trend across the
valleys and mountains. While the marine layer is shallow this
evening, it is expected to deepen overnight with low clouds moving
from coastal areas into the valleys. At the same time, high
clouds will increase ahead of the approaching storm system so
Wednesday will be cloudy in the morning with only partial clearing
in the afternoon. High temperatures will be in the 60s and 70s.

Rain is forecast to begin moving into NW San Luis Obispo County
late Wednesday night, with the timing shifted back somewhat from
previous forecasts.

***From Previous Discussion***

Models made a significant shift in the upper level pattern later
this week creating increasing uncertainty with the timing and
overall details of the storm, especially with the later Fri/Sat
period. Confidence is still high that the initial round of rain
will arrive Thursday into Friday morning, though the timing has
moved forward 5-10 hours from the previous forecast and there is a
possibility of additional timing adjustments as the models
recalibrate based on how storm evolves. The arrival of hi res
models Wednesday will help as well.

This first burst of rain still looks to be the strongest with
widespread rain rates between a quarter and half inch per hour and
locally as much as 0.75/hr. Orographics will play a big role with
upslope areas getting 2-3 times the amounts at sea level. This
will be particularly pronounced across southern Santa Barbara
County where up to 4 inches or locally higher are possible in the
mountains. There is 10-20% chance of thunderstorms across the area
as well.

No snow expected with this system except possibly a few inches,
mostly above 8000 feet.

.LONG TERM (SAT-TUE)...11/159 PM.

There is very low confidence in the Saturday forecast given
today`s huge pattern shift which resulted in the models cutting
off the upper low about 300 miles southwest of LAX Saturday
morning and then slowly moving it northeast on Sunday. If the
upper low stalls far enough offshore it could lead to a
continuation of steady moderate to locally heavy rain across the
area Saturday (especially south of Pt Conception) and possibly
even into early Sunday as the initial plume just pivots around
the low rather than progressing east. If the upper low ends up not
cutting off and returns to the original, more progressive
pattern, there may be still be some light showers south of Pt
Conception Saturday but much lighter and exiting sooner. The first
(and wetter) scenario is the currently favored option in the
models now but overall this is a very low confidence forecast.

The rest of forecast through early next week remains similarly
uncertain given the earlier issues. There are several ensemble
solutions still indicating another cutoff low along the West coast
with a chance of rain Monday and Tuesday.

&&

.AVIATION...12/0533Z.

At 0443Z at KLAX, there was a surface based marine inversion. The
top of the inversion was near 2500 feet with a temperature of 23
degrees Celsius.

High confidence in VFR conditions for KWJF and KPMD thru the
forecast period. Low to moderate confidence in the 06Z TAFs for
the coastal sites with IFR conds forecast. However, there is a
30% chance of LIFR conds developing between 08Z and 15Z. The
chance of CIGs clearing Wed afternoon is low confidence, and
timing could be off by +/- 2 hours. Low confidence in CIGs for
KBUR and KVNY, with a 30% conds could be VFR or LIFR.

KLAX...Low to moderate confidence in the 06Z TAF. Moderate
confidence in minimum flight cat, with a 20% chance LIFR conds
develop between 08Z-15Z. No significant east wind component is
expected.

KBUR...Low confidence in the 06Z TAF. There is a 40% chance low
clouds do not affect the site, and a 30% chance of LIFR conds if
low cloud do occur.

&&

.MARINE...11/839 PM.

High confidence in relatively calm winds and seas through
Wednesday, except for localized Small Craft Advisory (SCA) level
wind gusts to 25 knots near Point Conception and south to San
Nicolas Islands this evening. In addition, patchy fog is expected
tonight into Wednesday morning, with a chance for dense fog.

Southwest winds 15-30 knots will develop Wednesday night
across the outer waters as well as nearshore along the Central
Coast. A cold front to the northwest will pass through the region
Thursday and Thursday night. Gusty S to SW winds of 20-30 knots
will develop across the entirety of the coastal waters then shift to
NW behind the front. Lower confidence in winds Friday, as they
will be highly dependent on the track of the low. Seas across the
outer waters will increase to 12-14 feet, and 5-7 feet inside the
Southern California Bight.

From Thursday through Thursday night, the aforementioned storm
system will bring a slight chance of thunderstorms across the
coastal waters from the Santa Barbara Channel northward. Any
thunderstorms that develop will be capable of producing frequent
lightning, gusty and erratic winds, locally rough seas and even
waterspouts.

Moderate confidence in conditions improving some over the weekend,
but SCA winds are still possible.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...MW/CC
AVIATION...CC
MARINE...Phillips/Sirard
SYNOPSIS...CMC

weather.gov/losangeles

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

NWS Flagstaff Office