057
FXUS66 KSGX 302021
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
121 PM PDT Sat Aug 30 2025

.SYNOPSIS...
Warm and dry under sunny skies through the weekend. Heat peaks
Monday/Tuesday with some inland areas under a Heat Advisory.
Monsoonal moisture returns for Tuesday into the end of next week,
with chances for storms in the mountains and deserts each
afternoon.

&&

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

It`s a gorgeous, sunny day across Southern California, the perfect
start to a holiday weekend. High temperatures across the inland
regions are slightly above normal, around 2-5 degrees, while those
along the coast are a bit more seasonal. If you`re heading to the
beach this weekend, an uptick in southerly swell will lead to
elevated surf and strong rip currents at most beaches through at
least Monday, so swim with caution and always near a lifeguard.
Other than the surf, temperatures will continue to climb into early
next week as a elongated ridge over the central CONUS amplifies,
with the thermal ridge axis setting up over the Colorado River
Valley. By Monday, 850mb temps of 28-30C over the region should
usher in highs of 110-112F for the deserts and 100-106F for the
Inland Empire. The lack of a widespread marine layer yesterday and
today has resulted in warmer than expected temperatures across
the valleys and coastal regions, with limited cooling overnight
due to the stubborn monsoonal moisture left over from the past
week. With the building ridge, any return of the marine layer will
be patchy at best, and limited to near or just off the coast into
early next week. Given the expected patchiness, no widespread
dense fog is currently expected, but localized areas of visibility
below 2 miles won`t be out of the question.

Heat will peak Monday/Tuesday with temperatures 6-12 degrees above
normal across valleys and coastal terrain/foothills, and a Heat
Advisory is in effect for these areas. By Tuesday, monsoonal
moisture will surge northward into the mountains and deserts,
limiting temperatures a bit for these regions. With ample mid-
level moisture and instability, showers and thunderstorms look to
develop off the mountains Tuesday afternoon, similar to what was
observed this past week. A few storms will likely make it off the
mountains and into the urban parts of the Coachella Valley, with a
lower chance for spillover into the Inland Empire or San Diego
valleys. Brief, heavy rainfall, lightning, and very gusty winds
will all be possible near any storm.

The monsoonal moisture may hang around for a bit as a low off the
coast of San Francisco moves inland on Wednesday and a deepening low
over the Great Lakes pinch the ridge, breaking it down a bit but
maintaining high pressure over the region through the end of the
week. Global models continue to favor storms in the mountains each
afternoon Wednesday through Friday, but lesser confidence in
widespread storms or spillover into the urban regions. There is
substantial disagreement on the long-term pattern for the end of the
week and into the weekend, with the placement of the ridge likely to
determine temperatures and moisture surges/thunderstorm chances
across the deserts and mountains into the weekend. For now,
temperatures look to cool a bit from their peak on Monday/Tuesday
with both moisture and mid-level cloud cover limiting afternoon
heating. Have maintained at least slight chances for thunderstorms
each afternoon in the mountains into the weekend.

&&

.AVIATION...
302000Z...VFR through this evening region-wide. SCT-BKN low clouds
based 600-1000ft MSL start to develop along the SD county coast
after 08z Sunday and push up to 5 miles inland after 12z. 30-40%
chance BKN cigs along the Orange County coastline. Low clouds that
manage to develop will retreat back to the coast by 16-17z Sunday.

&&

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

&&

.BEACHES...
A long-period (15-16 sec) southerly swell (180-200 degrees) will
bring elevated surf through Tuesday, gradually subsiding
thereafter. Surf of 3-6 feet with occasional sets to 7 feet for
south-facing beaches. High rip current risk for all beaches. Beach
Hazard Statement in effect through late Monday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday evening for Orange County
     Coastal Areas-San Diego County Coastal Areas.

     Heat Advisory from 10 AM Monday to 6 PM PDT Tuesday for Orange
     County Inland Areas-San Bernardino and Riverside County
     Valleys-The Inland Empire-San Diego County Valleys-Santa
     Ana Mountains and Foothills.

PZ...None.

&&

$$

PUBLIC...Zuber
AVIATION/MARINE/BEACHES...KW