860
FXUS66 KSGX 300900
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
200 AM PDT Sat Aug 30 2025

.SYNOPSIS...
Warm and dry under sunny skies through the weekend. Monsoonal
moisture will increase again for Tuesday through the end of next
week, with increasing chances for storms to return to the
mountains and deserts. Other areas will see slightly warmer
conditions with highs up to 5 degrees above normal, warmest on
Monday and Tuesday.

&&

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

Today through this weekend...

A partially flattened ridge remains over the western half of the
CONUS, which has kept temperatures above average in recent days.
This has also allowed for some recycled monsoonal moisture in the mid
lats to be locked in place over the region, however, this moisture
will be much more depleted today and likely only resulting in a few
clouds to form over the mountains by later this afternoon. Because
of this, a very slight chance of an isolated shower, and possible
storm, exists over the highest elevations. It should be clear and
dry elsewhere. The marine layer is very sparse, with lack of
coverage at this hour and clear skies for all locations, even at the
coast. Patchy fog will be possible early this morning over the inner
coastal waters and where the low clouds are intersecting coastal
foothills, as well as within some of the lower-lying valleys. This
will be possible again tomorrow night, and is expected to be a
little more extensive than tonight, but with similar bases.

Monday through the end of next week...

The ridge is going to continue to strengthen and become more
amplified over the Great Basin. With this, temperatures will
continue to climb through Tuesday, especially within the Inland
Empire (IE). Possibly as early as Monday, and with growing
confidence to be more likely on Tuesday, will there be the need for
heat-related products issued for the inland valleys, and maybe even
within the lower deserts. At this time, it appears that the ridge
will begin to break down towards the end of the week with a gradual
cooldown and also some increased monsoonal moisture as the ridge
axis begins to shift a little closer to the CWA and allows for some
of the moisture to get advected up from the south. This may also be
enhanced by the formation of a tropical disturbance, as
deterministic models suggest. Depending on where the tropical
disturbance propagates, this might not only help to increase the
probability of shower and thunderstorm development over the
mountains and deserts, but might also help to keep the deserts
slightly cooler, going into the late part of the following week.

&&

.AVIATION...
300800Z...VFR through Saturday evening region-wide. Very patchy
coastal low clouds based around 800-1000 feet MSL 10-16Z Saturday
along the SD County coast. Low clouds based 600-1000 feet MSL start
to develop along the SD county coast after 06z Sunday, with slightly
greater coverage than tonight but still patchy.

&&

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

&&

.BEACHES...

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from 5 AM PDT early this morning through
     Monday evening for Orange County Coastal Areas-San Diego
     County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...Stewey
AVIATION/MARINE/BEACHES...Westerink