895
FXUS66 KSGX 041002
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
302 AM PDT Mon Aug 4 2025

.SYNOPSIS...
Not much change for today. Strengthening high pressure over the
southwest states will bring a warming trend for Tuesday through
Thursday with Thursday high temperatures as much as 5 to 10
degrees above average for inland areas. This will be followed by a
gradual cooling trend for Friday through next weekend with high
temperatures for next Sunday around average for most areas and
around 5 degrees above average for the deserts. Heat Risk will be
highest for Wednesday through Friday, peaking on Thursday. Night
and morning coastal low clouds will spread into portions of the
western valleys late each night early this week and again for next
weekend.

&&

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

.SHORT TERM (Today through Wednesday)...
Not much change in high temperatures is expected for today with
high temperatures mostly within a few degrees of average.
Strengthening high pressure over the southwest states will bring
warming for Tuesday through Thursday with Thursday high
temperatures as much as 5 to 10 degrees above average for inland
areas.

The marine layer is near 1200 to 1400 feet deep and will become
gradually shallower through Thursday, with night and morning
coastal low clouds and fog mostly just spreading into coastal
areas for early Wednesday and Thursday. As the marine layer
becomes a little shallower, there could be locally dense fog near
the mesas late each night.

Hazy skies will continue at times, mostly the result of smoke
from the large Gifford Fire along the border of central San Luis
Obispo and Santa Barbara Counties.

&&

.LONG TERM (Thursday through Sunday)...
The heat is expected to peak on Thursday with high temperatures as
much as 5 to 10 degrees above average for inland areas. High
temperatures on Thursday will range from the mid 70s to lower 80s
near the coast to the upper 90s to 105 for the Inland Empire and
114 to 118 for the lower deserts. Heat Risk will be highest for
Wednesday through Friday, peaking on Thursday. An Extreme Heat
Warning has been issued for the lower deserts for Wednesday
through Friday. The currently forecast Heat Risk would also
justify a Heat Advisory for the inland valleys on Thursday.

There will be a gradual cooling trend for Friday through next
weekend with high temperatures for next Sunday around average for
most areas and around 5 degrees above average for the deserts.
High temperatures for next Sunday are expected to range from the
70s near the coast to the 90s to around 100 for the Inland Empire
with 108 to 114 for the lower deserts.

Night and morning coastal low clouds will spread into portions of
the western valleys late each night for next weekend.

&&

.AVIATION...
041000Z....Coasts/Western Valleys... Low clouds based 700-1100 ft
MSL have pushed up to 15 miles inland. VIS reduced to 1-5SM over
higher coastal terrain and elevated western valleys. Clouds clear
back through the coast by 15-17z Monday morning. Low clouds will
likely reform over nearshore waters with similar bases Monday
evening. Pushing into coastal areas up to 10 miles inland after 06z
Tuesday.

Inland Valleys/Mountains/Deserts...VFR conditions prevail through
Tuesday morning.

Patches of smoke aloft (~10000-15000ft MSL) continue to pass over
Southern California from the Gifford Fire to our distant
northwest, likely persisting through today. No surface VIS issues
from smoke are expected.

&&

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

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Warning from 10 AM Wednesday to 8 PM PDT Friday for
     Coachella Valley-San Diego County Deserts-San Gorgonio Pass
     near Banning.

PZ...None.

&&

$$

PUBLIC...17
AVIATION/MARINE...KW