DesertWeather.com

714
FXUS66 KSGX 011839
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1139 AM PDT Sat Aug 1 2026

.SYNOPSIS...
The peak of the heat will occur through the weekend as an area of
high pressure stays over the region. The weather system will weaken
and push slowly eastward through the upcoming week, bringing a
slight cool down and increasing winds across the mountains and the
deserts. There will be increasing monsoonal moisture as well, but
chances for rainfall in the mountains continues to look limited by
the end of next week.

&&

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

The thin marine layer this morning allowed for only patchy clouds
near the coast and far western valleys. The strength of the high
pressure aloft is creating a larger inversion, where clouds may
stick to the coast through the afternoon at times. This high has
peaked near 600 dm, leading to the hottest temperatures of this heat
wave. Temperatures were slightly increased for the afternoon based
on yesterday`s heating. High temperatures will be well into the 90s
for coastal valleys, near 100-110 across the inland empire and San
Diego foothills, and upper 80s and 90s in the mountain areas. The
high pressure system begins to weaken on Sunday, allowing for a few
degrees of cooling. With the hot weather this weekend, heat risk
will be moderate to high, so please take proper precautions if going
outdoors. Outdoor recreation is discouraged during the daytime!

The high weakens slowly, then stabilizes by Monday into the upcoming
week. This will bring temperatures near to 5 degrees above normal
with minimal day to day changes. Temperatures in the 90s to near 100
in the Inland Empire can be expected, with lower deserts seeing a
slower cooldown with highs remaining over 110 degrees. Highs will be
in the 80s for coastal valleys. Marine layer clouds will form each
night and morning within 15 miles of the coast next week.

The high pressure system will eventually move eastward by Wednesday
into the latter part of next week, bringing in greater monsoonal
moisture. PWAT`s rise over an inch in the mountain and desert
regions, but rainfall does not seem likely over the mountains by
Thursday and Friday with chances near 15% or less. Temperatures will
stay relatively unchanged from the beginning of the week, with
increased humidity across the entire region.

&&

.AVIATION...
011800Z....Coasts...Areas of low clouds based around 700-1000
feet MSL will gradually form after 05Z and overnight, but in
somewhat random and intermittent fashion. Local vis 3-5SM on
higher coastal terrain. Any cigs Sunday morning will scatter out
by 16Z Sunday.

.Valleys/Mountains/Deserts...Mostly clear and VFR conditions to
continue through Sunday morning.

&&

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

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT Sunday for Orange County Coastal
     Areas-San Bernardino County Mountains-San Diego County
     Coastal Areas.

     High Surf Advisory until 5 PM PDT this afternoon for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Extreme Heat Warning until 8 PM PDT Sunday for Apple and Lucerne
     Valleys-Orange County Inland Areas-Riverside County
     Mountains-San Bernardino and Riverside County Valleys-The
     Inland Empire-San Diego County Mountains-San Diego County
     Valleys-Santa Ana Mountains and Foothills.

     Extreme Heat Warning until 8 PM PDT Monday for Coachella Valley-
     San Diego County Deserts-San Gorgonio Pass near Banning.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...MM