058
FXUS66 KSGX 151655
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
855 AM PST Sat Nov 15 2025

.SYNOPSIS...
A Pacific storm will continue to impact the region through the
weekend. Heavier and more widespread precipitation will develop
this morning, including a chance of thunderstorms. The weather
pattern will remain active with another winter storm expected to
impact the region for Monday into Tuesday with another system
expected to impact the region later next week.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

.Morning Update...

Widespread light to moderate showers continue to overspread the
area this morning as the area of low pressure off the coast slowly
moves northeastward toward Southern California. Hourly rain rates
west of the mountains have generally been near 0.20"/hr, with
some spots near over one third of an inch. The heaviest rainfall
with the storm system is currently moving onshore, so we can
expect the most intense rain to occur across our region late
morning into the early afternoon. Models show more intermittent
showers occurring by the evening into the overnight hours. Hi-res
models show the heaviest showers will be possible around the San
Diego metro areas, where some post-frontal showers may produce
hourly rain rates near 0.50"/hr. Not too much in way of
thunderstorm activity is noted this morning, but a slight chance
remains in the forecast through the night.

The forecast remains on track for isolated shower activity to
remain into Thursday, mainly along and west of the mountains. We
will continue to monitor the next weaker storm system that will
move into the area on Monday and Tuesday, as well as a possible
third weather system by later next week.

.Previous Discussion...

Scattered mostly light showers continue to lift north across the
region this morning with rainfall rates generally 0.10 inch per
hour or less. However, that will change drastically later this
morning as the upper level closed low currently around 300 mi west
of San Diego drifts eastward and a vort max lifts north over So
Cal. This forcing combined with forecast Integrated Vapor
Transport (IVT) of over 500 kg/m/s and PW near 1.5" will produce
widespread moderate to heavy precipitation today, mainly between 6
AM and 4 PM. Rainfall rates for urban areas are forecast to peak
around 0.30-0.50"/hr, and as high as 0.80"/hr on the south facing
mountain slopes. There is a 15-30% chance of thunderstorms today
as well, which could produce locally higher rainfall
rates/amounts. Rainfall rates of this intensity will likely
produce roadway flooding, especially in poor drainage areas, and
bring a threat of mud and debris flows in and below the recent
burn scars. A Flood Watch remains in effect from 4 AM through 10
PM today.

Additional total rainfall through Sunday evening will be around
1.50-2.25" for the coasts and valleys, 2-4" for the mountains,
and 0.50-0.80" for the deserts. Snow levels will remain above
7500 ft through the day, lowering to 6500-7000 ft tonight into
Sunday morning, then rising to around 7500-8000 ft during the day
Sunday, with snowfall totals of 1-4" above 7500 ft.

Rain turns to scattered showers this evening, some of which could
be heavy as thunderstorm chances continue, then weaken and become
more isolated Sunday morning. Isolated light showers will persist
through the day Sunday into Monday morning. We may get a brief
break late Monday morning before the next round of precipitation
moves in sometime during afternoon, heaviest and most widespread
late Monday into Tuesday morning. This second system will be
another slow mover with precipitation lingering into Wednesday. A
weak Atmospheric River is forecast to accompany this system, but
there is still a lot of spread in total rainfall amounts. For the
coasts and valleys, NBM 25th to 75th percentile precipitation
range anywhere from 0.10-0.20" on the dry end to around 1-1.5" on
the wet end. The chance of 48 hr rainfall totals exceeding 0.50"
is around 45-65%, and chance of exceeding 1" is 25-50%, lowest in
the Inland Empire. Snow levels with this storm will be lower,
falling to 5500-6000 ft Monday night, then rising to 6000-6500 ft
for Tuesday afternoon into Wednesday. Drier weather will then
follow for Wednesday afternoon through Thursday morning.

For the next potential storm later in the week, huge uncertainty
remains. Ensembles are split about 50/50 on the low tracking south
just off the coast (wetter) versus a more inside track (drier),
and a few ensemble members are completely dry. The timing is also
questionable, with precipitation onset as early as Thursday
afternoon and as late as Friday morning or afternoon.

Aside from precipitation, high temperatures will range from
around 10 to 20 degrees below normal through much of the week
with periods of breezy southwest to west winds as each storm
system moves through.

&&

..AVIATION...
151630Z...-SHRA with cloud bases 3500-7000 feet MSL with occasional
+RA with bases down to 1000-2000 feet and vis 1-5SM will continue
into this afternoon. 15% chance TSRA, highest for the coast and in
inland valleys through 22Z, then 25% chance TSRA migrates inland
after about 21Z. Precip decreases and associated CIG/VIS reductions
begin to lift from south to north after 23Z, with SCT -SHRA and ISO
-TSRA continuing through 05Z. ISO-SCT -SHRA thereafter with BKN
clouds based around 2500-3500 feet MSL.

Frontal band to bring south to southeast winds gusting 20-30 kts
west of the mountains, highest along coast, through 22Z. Winds turn
southwesterly after about 20Z and diminish along the coast, while
WSW gusts 25-40 kts pick up over mtns and desert slopes through
tonight.

Another round of heavier SHRA along the coasts and valleys along
with breezy southeast winds possible after 08Z Sun, bringing lowered
bases and reduced VIS, with high res guidance indicating highest
chances in SD County for impacts.

&&

.MARINE...
South winds 15-25 kts through 21Z will bring steep, mixed seas 5-8
feet throughout the coastal waters. See the Small Craft Advisory for
details. Winds become west-southwesterly and weaken after 21Z.

Additionally, heavy rain will lead to reduced visibility and
thunderstorms embedded within the rain resulting in gusty, erratic
winds, lightning, and possible waterspouts. A Marine Weather
Statement in effect through today contains more details.

Winds strengthen again Monday afternoon ahead of the next storm
system. There is still some uncertainty in exact intensity of winds,
but gusts in excess of 20 knots are possible along with another
round of precipitation.

&&

.BEACHES...
West swell 4-5 feet will combine with a south wind swell to create
elevated surf 4-6 feet with local sets to 7 feet through the late
afternoon. Additionally, there is a chance (20-30%) for
thunderstorms through late this afternoon. See the Beach Hazards
Statement for more.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 3 PM PST this afternoon for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Flood Watch through this evening for Apple and Lucerne Valleys-
     Coachella Valley-Orange County Coastal Areas-Orange County
     Inland Areas-Riverside County Mountains-San Bernardino
     County Mountains-San Bernardino and Riverside County
     Valleys-The Inland Empire-San Diego County Coastal Areas-
     San Diego County Deserts-San Diego County Mountains-San
     Diego County Valleys-San Gorgonio Pass near Banning-Santa
     Ana Mountains and Foothills.

PZ...Small Craft Advisory until 4 PM PST this afternoon for Coastal
     Waters from San Mateo Point to the Mexican Border and out
     to 10 nm-Waters from San Mateo Point to the Mexican Border
     Extending 10 to 60 nm out including San Clemente Island.


&&

$$

UPDATE...APR
PUBLIC...SS
AVIATION/MARINE...MM