021
FXUS66 KSGX 011528
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
828 AM PDT Wed Oct 1 2025

.SYNOPSIS...
Warming will spread inland for today and Thursday with Thursday
high temperatures a few to around 5 degrees below average. A low
pressure system moving inland through California on Friday will
bring stronger onshore flow with southwest to west winds for the
mountains and deserts gusting to 30 to 40 mph with isolated gusts
to around 50 mph on the east slopes of the mountains. There will
be cooling of as much as 4 to 8 degrees for the mountains on
Friday with continued cooling of a few more degrees for the
deserts on Saturday. Low pressure from the north will spread more
cooling inland for Sunday and Monday with Tuesday a few degrees
warmer.

&&

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

.Morning Update...

Low clouds will continue to dissipate out of western Orange County
this morning. Low clouds will reemerge this evening and slowly
fill into areas within 10 miles of the coastline overnight. We
will continue to see highs slightly below normal with elevated
winds for mountain and desert regions on Friday afternoon and
night. Otherwise, no forecast updates.

.Previous Discussion (240 AM Wednesday)...

.SHORT TERM (Today through Friday)...
High pressure to the southeast will bring a few degrees of warming
for today and Thursday with high temperatures on Thursday a few
degrees below average to around 5 degrees below average for the
valleys and inland Orange County. Thursday high temperatures will
range from around 70 near the coast to the lower to mid 80s for
the Inland Empire with the mid 90s for the lower deserts.

A low pressure system from the northwest moving into California
and Nevada on Friday will bring stronger onshore flow and
deepening of the marine layer with high temperatures as much as 4
to 8 degrees cooler for the mountains and high desert. Southwest
to west winds for the mountains and deserts will gust to 30 to 40
mph, locally to around 50 mph along the east slopes of the
mountains and in the northern Coachella Valley below the San
Gorgonio Pass.

Coastal low clouds will be much patchier early this morning as the
marine layer slowly decreases in depth through Thursday. Coverage
of low clouds will begin to increase for tonight into Thursday
morning with greater inland spread into the valleys for late
Thursday night into Friday morning as the marine layer begins to
deepen.

&&

.LONG TERM (Saturday through Tuesday)...
The low pressure system moving inland through California and
Nevada will weaken and accelerate inland on Saturday. High
temperatures for the deserts will continue to cool a few degrees
while the coast, valleys, and mountains warm a few degrees. High
temperatures on Saturday will range from the lower 70s near the
coast to around 80 for the Inland Empire with around 90 for the
lower deserts.

A low pressure system from the north will spread cooling inland
for Sunday and Monday with Monday high temperatures as much as 8
to 12 degrees below average for the mountains, valleys, and inland
Orange County. High temperatures on Monday will range from around
70 near the coast to the 70s for the Inland Empire with the mid to
upper 80s for the lower deserts. Tuesday high temperatures will
warm a few degrees, but still be as much as 5 to 10 degrees below
average for the mountains, valleys, and inland Orange County.

&&

.AVIATION...
011530Z....Coast...Low clouds based 1500-2000 ft MSL mainly over
Orange County. Scatter out by 15-17Z. Areas of low clouds based
around 1000-1500 feet MSL gradually developing after 04Z into early
Thursday.

Valleys/Mountains/Deserts...Mostly clear and VFR conditions today
and tonight.

&&

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

&&

.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...17
AVIATION/MARINE...Westerink

NWS Tucson (SGX) Office