780
FXUS66 KLOX 171729
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
929 AM PST Mon Nov 17 2025

.SYNOPSIS...17/327 AM.

A cooler storm system will spread rain from northwest to
southeast across the area late tonight through tonight, with
decreasing showers continuing into Tuesday. Wednesday will offer a
brief respite from the rain with warmer temperatures. Another
storms is slated to arrive next Thursday and linger into Friday.

&&

.SHORT TERM (TDY-WED)...17/748 AM.

***UPDATE***

Overall, based on current radar trends, forecast looks on track
for the immediate short term. Front is currently moving across San
Luis Obispo and Santa Barbara counties, generating light to
moderate rainfall. This front will move into Ventura county by
late then LA county by early this afternoon. Behind the front,
scattered showers can be expected into the evening. Additionally,
the instability along and behind the front look to be enough to
generate an isolated thunderstorm or two. Currently, have not seen
any lightning on the detection network, but would not be surprised
to see that change throughout the day.

With expected rainfall rates, mentioned below, there will likely
be a good amount of nuisance flooding across urban areas through
this evening. However with any thunderstorm development or heavier
showers, there will be a chance (20-30%) of reaching or slightly
exceeding USGS thresholds for the burn scars. So, will need to
monitor this potential through the evening.

So, do not anticipate any significant updates this morning to the
forecast. Just be prepared for a soggy day.

***From Previous Discussion***

Key Message:
Moderate, Advisory level flooding and wind impacts are likely
with the storm that will push through the region today and Tuesday
due largely to the extremely wet conditions we experienced ahead
of the storm. Protective actions for consideration include: 1)
Avoiding travel during the peak of the storm, which will likely be
this morning for San Luis Obispo and Santa Barbara Counties, and
more towards the afternoon/early evening for Ventura and Los
Angeles Counties 2) Have multiple ways to receive weather warnings
and messages from local officials.

Weather Details:
Moderate to embedded pockets of heavy rain will march south along
and ahead of a cold front through this evening. Along and behind
the front there is a 10-20 percent chance of thunderstorms through
Tuesday early evening. Peak rain rates of 0.25-0.50 inches per
hour will be common, with isolated rates of 0.80+ inches per hour
likely near thunderstorms and S-SW facing foothills/coastal
slopes(especially in the Santa Ynez mountains and western Ventura
mountains). Minor roadway/small stream flooding, additional
rockslides/mudslides, and shallow debris flows near recent burn
scars will be common due to this storm being on the heels of the
historic rainfall we received just a few days ago. There is a
20-30 percent chance of reaching debris flow thresholds (15, 30,
60 minute durations) in the recent burn scars.

The wet grounds will also bring an increased risk of downed trees
with strong winds associated with any stronger winds. We have
issued an impact based Wind Advisory for most mountains and
interior areas given the increased risk for wind impacts even if
onshore winds fall just shy of our technical criteria in some
areas. Convective showers and thunderstorms may increase this risk
outside of the Wind Advisory as well. There is also the potential
for isolated waterspouts along and ahead of the cold front.

A secondary peak of thunderstorm chances is Tuesday afternoon
focused across interior mountains into most of LA County given its
more conducive location with better moisture and instability on
the east side of the departing cold upper low. Any thunderstorms
that do form could be slow moving or even stationary, leading to
the potential for very isolated flooding concerns as well as
debris flows near recent burn scars, especially concerning the
unusually wet conditions with peak rates potentially 0.25-0.5 inch
per hour with very isolated 0.80+ inch per hour.

Snow levels are expected to be above 7000 feet during the onset
of this next storm, but are expected to lower to between 5000 and
6000 feet by Monday night, and around 4500 feet on Tuesday. Snow
accumulations of 1-3 inches will be possible for elevations above
6000 feet, with higher amounts above resort levels (above 8000
feet) likely. On Tuesday, there is a small chance of snow showers
reaching down to the Grapevine along I-5, but any accumulations
would likely be minimal.

Wednesday will continue to be cool with some breezy northerly
winds across the interior. If good radiational cooling conditions
(light winds and mostly clear skies set up) we could see our first
frost/freeze of the year for many interior areas with upper 30s
in play for colder/sheltered coastal valleys as well.

.LONG TERM (THU-SUN)...17/322 AM.

Below normal confidence in a Thursday/Friday system as even
slight changes in its track and speed will make a large difference
on how much if any rainfall we see. Although its very likely
this one will be less impactful overall than the early week storm.
However, there is a 10-20 percent chance of similar impacts for
Los Angeles and Ventura County given the early week storm will
probably be a bit weaker for these areas and the Thursday/Friday
system may target these counties. This will be another cold system
with snow levels potentially around 5000-6000 feet for a majority
of the storm with several inches of snow possible above this
level should the storm come in on the wet side.

Above normal confidence in dry conditions next weekend into the
following week with temperatures likely rebounding to at least
near normal after a prolonged period of cool and unsettled
weather.

&&

.AVIATION...17/1728Z.

At 1715Z at KLAX, there was no marine layer. There was a deep
moist layer up to around 10000 feet.

Overall, low to moderate confidence in 18Z TAF package. With
passing front and showers behind it, CIGs and VSBYs will likely
bounce around between VFR and IFR at most sites through the
period. So, low confidence in timing of any flight category
changes.

There will be a 15-25% chance of thunderstorms for all sites
through tonight. Any thunderstorms will be capable of producing
brief heavy rain, frequent lightning and gusty/erratic winds.

KLAX...Low to moderate confidence in 18Z TAF. Timing of rain as
well as timing of flight category changes could be +/- 3 hours of
current forecasts. There is a 20-30% chance of IFR CIGs 22Z-03Z.
High confidence in east to southeast winds around 10 knots
through 00Z then winds will shift to a westerly direction.

KBUR...Low to moderate confidence in 18Z TAF. Timing of rain as
well as timing of flight category changes could be +/- 3 hours of
current forecasts. There is a 20-30% chance of IFR CIGs 22Z-03Z.

&&

.MARINE...17/747 AM.

For the waters from southwest through northwest of the Channel
outside the southern California bight and the nearshore waters
along the Central Coast, Small Craft Advisory (SCA) level winds
continue through tonight. Seas will build to SCA levels through
today and persist through late Tuesday night, although there is a
chance for seas to decrease below SCA level by mid-day Tuesday.
Winds and seas will likely fall below SCA levels for Wednesday and
Thursday, then there is a moderate to high (30-50 percent) chance
of SCA conditions developing on Friday.

Inside the Southern California Bight, SCA level winds will
continue through tonight. Short-period seas will likely grow to
SCA levels by this evening. Conditions will likely fall below SCA
levels for Wednesday and Thursday, then there is a moderate- to-
high (30-50 percent) chance of SCA conditions developing on
Friday.

There is a 10-20 percent chance of thunderstorms across the
coastal waters through tonight. Any thunderstorms that develop
will be capable of producing brief heavy rain, small hail,
dangerous cloud to surface lightning, gusty and erratic winds,
locally rough seas, and possible waterspouts.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until noon PST today for
      zones 38-342-344-345-351>353. (See LAXNPWLOX).
     Wind Advisory in effect until noon PST today for zones
      340-341-346>348. (See LAXNPWLOX).
     High Surf Advisory in effect from 2 PM this afternoon to 10
      AM PST Tuesday for zones 340-346. (See LAXCFWLOX).
     Wind Advisory remains in effect until 4 PM PST this afternoon
      for zones 376>378. (See LAXNPWLOX).
     Wind Advisory remains in effect until 9 PM PST this evening
      for zones 379>382. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 AM PST Tuesday for
      zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 2 AM PST Tuesday for
      zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Wednesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Munroe/Gomberg/Thompson
AVIATION...RAT
MARINE...Hall/Lewis
SYNOPSIS...Smith

weather.gov/losangeles

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