122
FXUS66 KLOX 151720
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
920 AM PST Sat Nov 15 2025

.SYNOPSIS...14/758 PM.

An unusually strong storm system will bring widespread rain to the
area through Sunday. The heaviest rain will fall late tonight
through early Saturday afternoon. During the peak of the event
isolated strong thunderstorms will bring a moderate risk of
flash flooding, debris flows, and damaging winds. The stormy
pattern will continue and periods of rain are possible through
late next week.

&&

.SHORT TERM (TDY-MON)...15/906 AM.

***UPDATE***

Significant early season storm will continue to affect much of
the region into tonight. Periods of moderate to heavy rain which
moved in earlier this morning will continue to affect the area.
Widespread urban flooding along with debris flows in and around
recent burn areas will persist. A slight chance to chance of
thunderstorms is also possible especially this afternoon.

Pay close attention to the latest warnings and statements
throughout the day. Easiest way to stay abreast of the situation
is to monitor NOAA Weather Radio or go to our web site at
www.weather.gov/losangeles.

***From Previous Discussion***

...MODERATE TO HIGH RISK OF DANGEROUS FLASH FLOODING, DEBRIS
FLOWS, AND DAMAGING WINDS THROUGH TONIGHT...

The storm has shifted into the 2nd phase as Friday`s cold front
has exited the area. Phase 2 involves an upper low that is
currently 250 miles to the SW of KLAX. A low level jet riding up
the east side of the has added plenty of energy and has even
produced a baroclinic leaf. PWs in this plume of mositure are near
1.4 inches (about 1 inch greater than normal). Lgt-mdt rain is
currently falling over most of the area. this will all change
around dawn. A well formed vort lobe with some embedded lightning
is riding up the east side of the low. This vort lobe will kick
the storm up a couple notches and the rain will become moderate
with pockets of heavy rain. There will be enough lift and
instability to bring a chc of TSTMs. While there is enough twist
in the lower atmosphere to allow any TSTM that forms to produce
severe weather or even a weak tornado, the real threat from any
convection will be the rainfall rates which will be close to 1
inch per hour. These rainfall rates on top of the already
saturated grounds will could well produce flash flooding anywhere.
The recent burn areas, of course, will be most vulnerable to
flash flooding and debris flows. A flash flood watch is in effect
for all of the area.

Areas north of Point Conception will not be immune from this
system as the vorticity moves to the NW and into and over the
area.

Most mdls show a marked decrease in rainfall this afternoon but a
few mdls do not let the rain up and there is a 30 percent chc
that moderate rainfall could continue well into the afternoon.

Additional rainfall through this afternoon will likely range from
1.5 to 2 inches for the csts/vlys south of Pt Conception and 2 to
4 locally 5 inches for the coastal slopes. The interior sections
and areas north Pt Conception should see around an inch to an inch
a quarter. Snow levels will remain above 7500 ft and snow will not
be a factor with this storm.

This is a dangerous situation and all residents of LA/VTA and
eastern SBA counties are urged to monitor this storm closely and
follow the directions of all emergency personnel.

The low will linger in the area overnight. The cold core will
bring enough instability to continue the chance of showers and
perhaps an isolated TSTM. There will not be that much dynamics so
the shower activity will be much less organized. Rainfall amounts
will be less homogeneous but will likely range from a quarter
inch to an inch. Some showers may have rainfall rates a little
over a half inch per hour.

There is a fair amount of disagreement on the evolution of the
upper low Sunday with most solutions shoving the upper harmlessly
to the east. 30 percent or so of the solutions, however, still
show the low close enough to bring some rain. So the Sunday
forecast calls for partly to cloudy skies with a 30 to 40 percent
chc of rain. This forecast may be a little on the pessimistic
side.

Sunday evening and into Monday a colder upper low scoots down the
west coast and into the state. A chance of rain will develop
across the Central Coast after midnight and the rain will likely
sweep over the area during the day. This is a colder system and it
will not hold nearly as much water as today`s storm. Rainfall
totals from early Monday morning through Monday evening will
likely range from .75 to 1.5 inches with local 2 inch amounts in
the mtns. This is a colder system and snow levels will lower from
7000 ft to 6000 ft by evening.

As with almost all rain events this late in the year max temps
across the csts and vlys will be in upper 50s to mid 60s all three
days or 6 to 12 degrees blo normal.

.LONG TERM (TUE-FRI)...15/256 AM.

Rain will taper off and end on Tuesday as the upper low pushes off
to the south and east. The Central will likely be dry. Any
additional rainfall will be light, under a quarter inch. Max
temps should rise a few degrees, but will still be below normal
with csts and vlys only reaching the mid 60s.

A little pop up ridge should bring one complete day of dry weather
on Wednesday. Max temps will rise a few more degrees, but highs
will remain many degrees blo normal.

Another system is slated to affect the state on Thursday and
Friday. Since the storm is so far out in time, there is
considerable disagreement on the exact timing and intensity of
this system. Best to wait a little bit before talking about
specifics and just realize that it could be wet couple of days.

&&

.AVIATION...15/1720Z.

At 1700Z at KLAX, there was no marine layer. There was a deep
moist layer up to at least 10000 feet.

Overall, low confidence in 18Z TAF package. With periods of
moderate to heavy rain through this evening, CIGs and VSBys will
bounce from MVFR to LIFR levels at all sites. Overnight, the rain
is expected to decrease in intensity, but CIGs and VSBYs will
likely remain in the MVFR to IFR levels.

KLAX...Low confidence in 18Z TAF. CIGs and VSBYs will bounce
between MVFR and LIFR levels through this evening, and between
MVFR and IFR overnight. East-southeast winds around 8 knot are
expected to develop in the 21Z-00Z time frame, but there is a 50%
chance that winds will not shift to the east to southeast.

KBUR...Low confidence in 18Z TAF. CIGs and VSBYs will bounce
between MVFR and LIFR levels through this evening, and between
MVFR and IFR overnight.

&&

.MARINE...15/852 AM.

There is a 20-30% chance of thunderstorms across the coastal
waters south of Point Conception 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.

For the Outer Waters, moderate confidence in the winds forecast
through today, otherwise moderate to high confidence in the
forecast. Some Small Craft Advisory (SCA) level seas this morning
will slowly subsiding through this afternoon, with a 20% chance of
SCA level SW-W winds. On Sunday, winds and seas are expected to
be below advisory levels. For Sunday night through Tuesday, high
confidence in SCA level seas with a 30-40% chance of SCA level
winds. For Wednesday, high confidence in winds and seas remaining
below SCA levels.

For the Inner Waters north of Point Sal, seas near SCA levels can
be expected thru this afternoon but should remain below these
levels. On Sunday, high confidence in winds and seas remaining
below SCA levels. For Monday through Tuesday, high confidence in
SCA level seas with a 30-40% chance of SCA level winds on Monday.
For Tuesday through Wednesday, high confidence in winds and seas
remaining below SCA levels.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. Conds should be below SCA levels
through this evening except for a 30% chance of SCA wind gusts at
times this afternoon and early evening. For tonight through
Sunday, high confidence in winds and seas remaining below SCA
levels. On Monday, there is a 60-80% chance of SCA level winds
across all the southern Inner Waters. For Tuesday through
Wednesday, high confidence in winds and seas remaining below SCA
levels.

&&

.BEACHES...15/1213 AM.

A moderately long period west-northwest swell will bring
hazardous surf conditions to portions of Southwest California
today into at least this afternoon. In addition to the west-
northwest swell, a storm system will continue to bring gusty
southerly winds which will add a southerly wind swell component to
the surf. HIGH SURF ADVISORIES remain in effect for the Central
Coast, the Ventura County Beaches, the L.A. County Beaches, as
well as a Beach Hazards Statement for the Santa Barbara South
Coast. Please refer to the LAXCFWLOX and LAXSRFLOX for details.

There is a 20-30% chance that HIGH SURF ADVISORIES may be needed
for the LA county beaches today and tonight.

Additionally, there is a 20-30% chance of thunderstorms across
all the beaches at times from late this afternoon through
Saturday night. Any thunderstorms that form will be capable of
producing locally strong winds, small hail, dangerous lightning,
heavy rainfall, and possibly even a weak/brief tornado.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Flood Watch remains in effect through this evening for zones
      87-88-346>358-362-366>383-548>550. (See LAXFFALOX).
     High Surf Advisory in effect until 3 PM PST this afternoon
      for zones 340-346-354-362-366. (See LAXCFWLOX).
     Beach Hazards Statement in effect until 3 PM PST this
      afternoon for zones 349-350. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke/Sirard
AVIATION...RAT
MARINE...Sirard
BEACHES...RAT
SYNOPSIS...30

weather.gov/losangeles

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