378
FXUS66 KSGX 131727
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
927 AM PST Thu Nov 13 2025

.SYNOPSIS...
The cooling trend will continue today with gusty southwest winds
for the mountains and deserts this afternoon and evening with
gusts to 35 mph. A Pacific storm will bring increasing chances for
showers beginning tonight with precipitation becoming heavy at
times for late Friday afternoon through Saturday with the most
widespread and heaviest rainfall expected late Friday night and
Saturday. There is also a chance of thunderstorms for Friday night
into Saturday evening. More widespread south to southeast winds
for Saturday mourning will gust to 35 mph. Scattered showers will
continue into Sunday. Additional showers are likely at times
next week, but with much lower confidence in the details.

&&

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

.Morning Update...

An impressively shallow marine layer continues this morning with
areas of fog and haze closer to the coast. Visible satellite shows
two distinct areas of low pressure off the West Coast. One larger
low off the far Northern California coast and another weaker
system directly west of Point Conception. Scattered mid-level
clouds will continue to work their way into our region today,
becoming cloudier by later in the afternoon/evening. The frontal
band that will impact SoCal is currently giving a dreary day
across the Bay Area to the Monterey. Virga/light showers are
possible later this afternoon across SoCal, but models are honing
in on light to moderate rainfall primarily impacting areas of the
LA Basin on Friday morning/afternoon. As the low pressure system
moves closer, more widespread rainfall over our entire region will
unfold by Friday night through Saturday night. Please see the
hydrology section below for rain/snow details.

Model projections continue to point to a continued active weather
pattern for at least the first half of next week. This will bring
cooler and breezier weather, along with the chance of
precipitation over SoCal.

.Previous Discussion (438 AM PDT)...

.SHORT TERM (Today through Saturday)...
A low pressure system centered well off the northern California
coast will move slowly toward the east and southeast today and
Friday with the storm centered to the southwest of Point
Conception early Saturday morning. It will move slowly toward the
east on Saturday, then toward the east and northeast for Saturday
night and Sunday with growing model differences in the placement
of the center.

High temperatures will continue to cool today. There will be
greater cooling of high temperatures on Friday with high
temperatures as much as 5 to 10 degrees below average for the
mountains, valleys, and inland Orange County. High temperatures on
Friday will be mostly in the mid 60s to lower 70s for the coast
and valleys and around 80 for the lower deserts. There will be
additional cooling on Saturday with the greatest cooling for the
lower deserts. High temperatures on Saturday will be mostly in the
60s for the coast and valleys and around 70 for the lower
deserts.

For today and Friday, there will be periods of gusty southwest
winds for the mountains and deserts with gusts to 35 mph. More
widespread southeast winds are expected on Saturday morning with
gusts to 35 mph.

Please see the hydrology section below for additional information
on rainfall through Sunday and related impacts.

&&

.LONG TERM (Sunday through Wednesday)...
Scattered showers will continue into Sunday with additional
showers likely at times next week, but with much lower confidence
in the details. Those systems are not expected to be as warm with
snow levels falling to around 6000 feet at times.

&&

.HYDROLOGY...
A Pacific storm with a moisture feed from an atmospheric river will
bring increasing chances for showers beginning tonight with
precipitation becoming heavy at times for late Friday afternoon
through Saturday with the most widespread and heaviest rainfall
expected late Friday night and Saturday. There is also a chance of
thunderstorms for Friday night into Saturday evening. Scattered
showers will continue into Sunday. There will be additional
chances for showers for much of next week, but with much lower
confidence in the details.

Through Sunday, rainfall for Orange and southwestern San
Bernardino Counties is expected to range from around 3 inches
near the coast to 4 to 6 inches for the mountains, locally
exceeding 7 inches on the south facing coastal slopes. For San
Diego County, rainfall is expected to range from around 2.5
inches near the coast to 3 to 4 inches for mountains with locally
greater amounts. For the high desert, 1.5 to 2.5 inches of
rainfall is expected with 1 to 1.5 inch for the lower deserts.

These rainfall amounts along with the potential for periods of
higher intensity rainfall for late Friday night through Saturday
could produce debris flows in burn areas, significant ponding of
water on roads and highways, and urban and small stream flooding.
The current forecast for the San Diego River has the river at
Fashion Valley rising to near monitor stage at 4 PM on Saturday,
sufficient to flood low-water crossings.

Snow levels above 10000 feet will lower to around 8000 feet for
late Saturday and 7000 to 7500 feet on Sunday. There could be 3 to
6 inches of snowfall for Saturday night and Sunday, mostly above
7500 feet.

&&

.AVIATION...
131730Z...Coasts/Western Valleys...A very patchy deck of low stratus
based near 200-400ft MSL briefly brought CIGs and VIS restrictions
to KSAN and KSNA this morning, but have pulled back out over the
waters. VFR conditions will prevail through the day with increasing
mid level clouds based around 6000-7500ft MSL ahead of an incoming
storm system. Lower clouds with varying bases from 2000-4000ft
increase after 09z but confidence/timing of any potential CIGs is
low. Increasing chances of isolated areas of -RA after 06z Friday.

Otherwise...VFR conditions will continue through Friday morning.
Mid and high clouds at 5-15 kft will gradually increase.

&&

.MARINE...
A storm system will approach Friday and move through Saturday and
Sunday, boosting southerly winds and seas. Occasional heavy rain
Saturday could reduce visibility. There is a slight chance of
thunderstorms Friday night through Saturday night.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

UPDATE...APR
PUBLIC/HYDROLOGY...17
AVIATION/MARINE...Munyan