042
FXUS66 KLOX 131138
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
338 AM PST Thu Nov 13 2025

Updated Aviation Section

.SYNOPSIS...12/1107 PM.

A large storm system will move into the Central Coast this
afternoon and will continue further south tonight into Friday.
The storm will generate periods of moderate to heavy rain this
evening through Saturday, and possibly into early next week.
Flooding of roadways and burn scars is possible, especially
Friday and Saturday.

&&

.SHORT TERM (TDY-SAT)...13/305 AM.

POTENTIAL FOR SEVERAL INCHES OF RAIN ACROSS THE AREA WITH MAJOR
IMPACTS MAINLY FRIDAY AND SATURDAY.

A large long wave pattern covers the CONUS with a huge ridge
covering a width from NV to MO. A compact low is moving up the
backside of the ridge, but will not be able to make much eastward
progress and this will allow it to affect CA for the next 3 days
with an emphasis on Srn CA on Friday and Saturday.

Today will not be that action packed as the system is still a ways
off of the coast. Rain will likely develop across NW SLO county
later this morning. Rain will overspread the entire Central Coast
late this morning and during the afternoon as the front moves into
the area. Rainfall amounts will mostly be under a quarter inch
with the usual exception of the far NW tip of SLO county where
.75" of rain could fall. The sfc gradient will increase over SLO
and SBA counties as the front approaches. The winds will increase
in kind and advisory level wind gusts will develop across much of
the two county area. A Wind Advisory from 8 AM to 6 PM is in
effect for south wind gusts up to 45 mph. The rest of the area
will see partly cloudy skies turning mostly cloudy during the
afternoon. Max temps will mostly be in the 60s up and down the
csts and vlys.

Tonight through the predawn hours Saturday the low will move due
south and will end up 250 miles to the SW of Pt Conception. At the
same time a front that originates well to the north of the area
and is separate from the upper low will push through the area.
The entire area will get rain during this period. The strongest
rain will occur over the Central Coast at this time. From late
this evening through dawn the front and the heaviest rain will
move across southern SBA county and

However, there are some solutions that place the upper low in a
much less favorable location that results in quite a bit less
rain. This is a less likely scenario than the one above but still
possible. By Thursday there should be more clarity on the track of
the low and at that point consideration will be given to any
possible Flood watches.  VTA county. It is during this
period when the south flow ahead of the front will interact with
the transverse ranges and produce the heaviest rain. Rain will
move in to LA county around dawn and the entire morning commute
will be wet. Mdls have consistently shown the front weakening as
it moves over LA county and rainfall rates and amounts will likely
end up not as strong as they were over srn SBA county and VTA
county. Still the Malibu area could see a period of heavier rain
right around sunrise. There will be a lull in the rainfall in the
afternoon with even some dry periods (esp for the Central Coast)
and much less in the way of rainfall rates. Peak Rainfall rates
will be mostly around a half inch per hour except across the south
facing slopes from Pt Conception to Ventura county where 1 inch
per hour rates will be possible. There is also a slight chc of a
TSTM with the threat mostly confined to the Central Coast.
Rainfall totals for most of the csts and vlys will be around an
inch (.5 to .75 inches for LA County) with the exceptions of NW
SLO and the transverse range coas

However, there are some solutions that place the upper low in a
much less favorable location that results in quite a bit less
rain. This is a less likely scenario than the one above but still
possible. By Thursday there should be more clarity on the track of
the low and at that point consideration will be given to any
possible Flood watches. tal slopes which may well see
three inches of rain.

There is still some uncertainly in the Friday night Saturday
forecast as it involves the trajectory of a cut off low. Ensemble
forecasts and the short range hi rez mdls are currently favoring a
trajectory (sweeping up to the NE and over LA/Orange counties)
that will be favorable for another burst of moderate to heavy
rain. This system will bring the heaviest rain to areas south of
Point Conception. The key factor with this system will be its PWAT
values which are a little over 1.5 inches as it picks up some sub
tropical moisture. As mentioned there is less certainty with this
system but it looks like it will deliver an additional 2 to 4
inches of rain with the peak occuring Saturday morning. Again
rainfall rates would be in the half inch per hour with local one
inch per hour amounts possible. Much less rain will fall across
the Central Coast - a half inch to an inch.

With this in mind, residents, especially those in vulnerable
areas, should start taking precautions immediately to prepare for
the storm and protect their interests. This scenario would
potentially create many significant impacts area-wide, including
possible debris flows in the burn areas, significant ponding of
roads and highways, mudslides through the canyons, fallen trees,
etc.

Later today both systems will be well in the range of the hi rez
short range weather mdls and ensembles. These will be analyzed
and decisions will be made on the issuance of any needed Flood
Watches.

.LONG TERM (SUN-WED)...12/1154 PM.

Both the EC and GFS while not in the greatest synoptic agreement
show enough moisture and energy to keep a 30 to 40 percent chc of
rain in the forecast through the period. Much of these pops are
likely the result of ensemble smearing and there will be some dry
periods as well as wet ones. PWs are much lower than during the
Fri/Sat stormy period and additional rainfall amounts across the
entire 4 day period will probably end up in the half inch to 1
inch range. That said this weather pattern has be so changeable
would not be surprised if this period`s actual weather turns out
to be something else.

Good confidence that there will be little day to day changes in
the temperatures. Max temps will mostly be in the lower to mid
60s across the csts/vlys which is 6 to 12 degrees blo normals.

&&

.AVIATION...13/1137Z.

At 1043Z, the marine layer depth was around 200 feet. The top of
the inversion was near 2000 feet with a temperature around 20
degrees Celsius.

Moderate confidence in all TAFs. Onset of any rain may be off +/-
4 hours, but confidence in rain occuring through the period is
high, except for KPMD and KVNY. For sites south of Point
Conception, rain may be delayed until after 06Z Fri. When rain
occurs, there will likely be bursts of +RA with IFR vsbys at all
sites. Otherwise, MVFR cigs and vsbys are likely with any rain.
Wind changes may be off +/- 3 hours.

There is a 10-20% chance for TSTMs from 21Z through the period
for KSBA north, and after 00Z south. Any TSTM can produce
lightning, abrupt and sudden wind shifts, and brief, heavy
downpours.

KLAX...Moderate confidence in TAF. Onset of rain may be off +/- 4
hours. Winds are expected to become south to southeast after
14/03Z. High confidence in east wind component of at least 8 kts
through around 15/00Z once winds shift SE to E.

KBUR...Moderate confidence in TAF. Onset of rain may be off +/- 4
hours.

&&

.MARINE...13/134 AM.

High confidence in the forecast for impacts and moderate
confidence for timing. A storm system will bring gusty winds,
steep short period seas, and a slight chance of thunderstorms
across the entire waters through at least Saturday morning. Any
thunderstorms that develop will be capable of producing frequent
lightning, gusty and erratic winds, locally rough seas and even
waterspouts. These will be dangerous conditions for boaters,
especially for the coastal waters along the Central Coast to the
western Channel Islands with gale force winds, steep choppy waves,
and seas in excess of 10 feet. Boaters are advised to remain in
safe harbor.

Expecting Small Craft Advisory (SCA) conditions to become more
widespread for the waters southwest to northwest of the Channel
Islands including the nearshore Central Coast waters into this
morning from northwest to southeast. Gale Force winds are expected
for the waters adjacent to the Central Coast, including
nearshore, from this morning through this afternoon. 20-30 knot
winds will follow. Seas will build to hazardous levels (up to 15
feet) throughout today, then likely decrease to below 10 feet
after Saturday morning.

Inside the California bight, winds and seas will remain below SCA
levels through at least early Thursday morning, then winds will
begin to increase this afternoon. SCA level south- southeast
winds (20-30 knots) will be common through at least early Friday
morning, but there is a moderate chance that SCA conditions
(winds and seas) may linger into Friday evening. Ocean conditions
are then expected to be relatively calm for the rest of the
weekend.

&&

.BEACHES...13/109 AM.

A moderately long period west-northwest swell will bring hazardous
surf conditions to portions of Southwest California late Thursday
through at least Saturday morning. In addition to the west-
northwest swell, a storm system will bring produce southerly winds
which will add a southerly wind swell component to the surf. High
Surf Advisories have been issued for the Central Coast and
Ventura County beaches. Please refer to the CFWLOX and SRFLOX for
details.

There is a chance for High Surf Advisories to be issued for Los
Angeles County (50%) and Santa Barbara County (20%) for the late
Thursday night to early Saturday morning period.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 8 AM this morning to 6 PM PST
      this evening for zones 340>348. (See LAXNPWLOX).
     High Surf Advisory in effect from midnight tonight to 9 AM
      PST Saturday for zones 340-346. (See LAXCFWLOX).
     High Surf Advisory in effect from 3 AM Friday to 9 AM PST
      Saturday for zone 354. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 9 AM PST this morning
      for zones 645-673. (See LAXMWWLOX).
     Gale Warning in effect from 9 AM this morning to 4 PM PST
      this afternoon for zones 645-673. (See LAXMWWLOX).
     Small Craft Advisory in effect from 4 PM this afternoon to 3
      PM PST Friday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 4 AM PST early this
      morning for zone 670. (See LAXMWWLOX).
     Gale Warning in effect until 4 PM PST this afternoon for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Saturday for
      zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke
AVIATION...Lewis
MARINE...Lewis
BEACHES...Lewis
SYNOPSIS...MW/CC

weather.gov/losangeles

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