437
FXUS66 KSGX 121151
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
451 AM PDT Mon Oct 12 2026

.SYNOPSIS...
A low pressure system moving southward into the Great Basin will
maintain cool, showery weather today with showers ending from the
northwest tonight. It will be warmer and dry for Wednesday through
Saturday with developing Santa Ana winds strengthening for Friday
into Saturday. Moderate HeatRisk could return for the coast into
the western valleys for Friday through Sunday.

&&

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


...UPDATED AVIATION DISCUSSION...

.SHORT TERM (Today through Wednesday)...
A closed low pressure system centered over Oregon early this
morning will move southward into Nevada today and tonight, then
move east for Tuesday night and Wednesday.

More widespread showers will continue along and west of the
mountains through the morning. The greater coverage during the
afternoon will be for the inland valleys into the mountains.
Showers will continue into the evening, then decrease and end from
the northwest by Tuesday morning.

Through tonight, additional rainfall could range from 0.10 to 0.25
inch near the coast to 0.50 to 0.75 inch in the mountains, locally
to 1.25 inches on the coastal slopes of the San Bernardino
Mountains. The snow level will lower to 7500 feet for this
afternoon and to 6500 feet by late this evening. There could be a
few inches of snowfall on the higher peaks, mainly above 7500
feet. For areas that clear late tonight, there could be some
patchy dense fog for late tonight into early Tuesday for lower-
lying portions of the Inland Empire and the adjacent mountains in
San Bernardino and Riverside Counties.

High temperatures for today will remain around 5 degrees below
average near the coast to 15 to 20 degrees below average for the
mountain, deserts, and inland valleys. High temperatures for today
for the coast and valleys will range from the lower to mid 60s for
the inland valleys to around 70 near the coast. High temperatures
in the lower deserts will be mostly in the mid to upper 70s. Not
much change is expected in high temperatures on Tuesday for the
desert. There will be warming of a few degrees near the coast to
around 5 degrees for the inland valleys into the mountains.

High pressure off the California coast and developing offshore
flow on Wednesday will bring greater warming with high
temperatures warming around 5 degrees near the coast to 8 to 12
degrees for the inland valleys into the mountains. High
temperatures on Wednesday will be mostly in the mid 70s to around
80 for the coast and valleys with some of the western valleys
reaching the lower 80s. High temperatures for the lower deserts
will be in the lower to mid 80s.

&&

.LONG TERM (Thursday through Sunday)...
High pressure off the California coast will expand across northern
and central California while low pressure develops over northern
and central Baja. High temperatures will continue to warm through
Friday. High temperatures on Friday will be a few degrees below
average for the deserts to 5 to 10 degrees below average for the
mountains. For the coast and valleys, high temperatures will range
from a few degrees above average for the inland valleys to 10 to
15 degrees above average for coastal areas. High temperatures on
Friday for the coast and valleys will range from the upper 70s for
the far inland valleys to the lower to mid 90s for the western
valleys and inland coastal areas. Areas near the coast will be
mostly in the 80s.

High temperatures on Saturday will cool a few degrees while inland
areas warm a few to around 5 degrees on Sunday. For Friday through
Sunday where will be Moderate HeatRisk for coastal areas into the
western valleys, the result of hot days and warmer nights. That
Moderate HeatRisk would be supportive of Heat Advisories for those
areas.

There could be moderate strength east to northeast Santa Ana winds
at times for Thursday through Saturday with ECMWF ensemble output
strongest on Friday.

&&

.AVIATION...
121130Z...Coastal/Inland Basin...SCT -SHRA will continue today with
cigs 2500-3000 feet MSL in -SHRA, otherwise bases 3500 feet MSL.
-SHRA tapering off and gradually scattering out after 03Z KSNA/KONT
and after 12Z Tuesday at KCRQ/KSAN.

Mountains...SCT -SHRA will continue through 00Z. BKN-OVC MVFR cigs
and obscured terrain will linger through Mon afternoon, with
occasional vis 2-5 SM with -SHRA. Clearing north to south tonight.

Deserts...SCT -SHRA with occasional BKN clouds based around 5000-
7000 feet MSL this morning, scattering out during the afternoon.

&&

.MARINE...
No hazardous marine conditions are expected through Friday.

&&

.BEACHES...
A combo southerly and westerly swell will continue through Tuesday,
generating surf 3-5 feet with local sets to 7 feet, along with
strong rip currents. Late morning high tides near 7 feet will
continue, producing minor coastal flooding. Check the Coastal Flood
Advisory for details.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 2 PM PDT Tuesday for Orange County
     Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...MM

NWS San Diego (SGX) Office