271
FXUS66 KSGX 151845
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1145 AM PDT Wed Jul 15 2026

.SYNOPSIS...
The peak of the heat will last through Thursday, with conditions
not as hot by Friday into early next week. Elevated heat risk will
remain through much of next week. Daily chances for monsoon
thunderstorms will occur through the weekend, highest on Thursday
and Friday in the mountains and locally into the deserts.
Temperatures stick near average for the first half of next week
with minimal chances for thunderstorms in the mountains.

&&

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

Cumulus clouds are beginning to bubble over the mountains via
satellite and out our weather windows at the office as we near the
lunch hour. The chance is there for a few showers and weak storms
to develop over the highest terrain along peninsular ranges from
the Mexican border to the Big Bear Lake region later this
afternoon. PWAT values are not as high as yesterday with less
instability, but we`ll have to see what Mother Nature has in store
for us. Temperatures will reach their peak this afternoon, where
moderate heat risk will be present for many inland, locally major
for far inland valleys and the lower deserts. Temperatures will
lower a few degrees by Thursday, whilst heat alerts remain in
effect until Thursday evening. Highs will top our near to just
over 100 degrees for inland valleys from Ramona to Ontario. Even
the mountains will be warm with highs in the 80s and 90s.

Subtle increases in moisture are seen in model guidance by
Thursday and Friday, leading to an increased chance of showers
and thunderstorms across the mountain areas, locally into the
deserts. A little more hesitant with this forecast due to lack of
instability seen in the latest guidance, so confidence is on the
lower end. We will continue to be right on the edge of the storm
activity through Saturday with chances near 15-40% each afternoon
and early evening in the mountains, and north of Big Bear in the
high desert.

By Sunday into the first part of next week, high pressure over the
Rockies shifts east into the Southern Plains. This will bring
clockwise monsoonal flow around the high to shift eastward with
it, moving more into Arizona and New Mexico. Moisture looks to
remain elevated for our area though, so cumulus clouds forming
over the mountains each day is a good bet, but there is
increasing confidence that these will have a tough time producing
any rainfall. Temperatures will remain near average each day with
marine layer clouds blanketing areas up to 20 miles inland each
night and morning.

&&

.AVIATION...
151800Z....Coast/Valleys...VFR prevailing. Very patchy low clouds
with bases 700-1000ft MSL may impact coastal TAF sites again
tonight. Highest chances for KSAN (~65-75% chance of CIGs overnight
at KSAN, 45-50% chance for KCRQ and 30-45% chance for KSNA). Impacts
most likely after 08z Thur. Any clouds will quickly move out
by 16z Thur. Otherwise, FEW high clouds AOA 15,000ft MSL.

.Mountains/Deserts...SCT Cu based around 12,000ft MSL along with
ISO TSRA over mountain ridges this afternoon and again Thursday
afternoon. Otherwise, FEW-SCT high clouds AOA 15,000 ft and VFR.

&&

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

&&

.BEACHES...
Astronomical high tides will peak again around 7.0 feet this
evening. High tides combine with a modest south swell (2 ft swell at
13-15 seconds from 190 degrees) to generate surf of 3-5 ft for south-
facing beaches and 2-4 ft elsewhere. This will produce areas of
coastal flooding in low lying areas, boardwalks, beach parking lots,
and beach adjacent streets during evening high tides. A Beach
Hazards Statement remains in effect through Wednesday evening and
contains further details. There will be an increased risk of rip
currents through Wednesday.

High amplitude southerly swell (4-5 ft) will arrive this weekend,
bringing elevated surf and strong rip currents for Sunday and into
early next week. Highest surf will be along south and southwest-
facing 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 through this evening for Orange County
     Coastal Areas-San Diego County Coastal Areas.

     Heat Advisory until 8 PM PDT Thursday for Orange County Coastal
     Areas-San Diego County Coastal Areas.

     Extreme Heat Warning until 8 PM PDT Thursday for Coachella
     Valley-Orange County Inland Areas-Riverside County
     Mountains-San Bernardino County Mountains-San Bernardino
     and Riverside County Valleys-The Inland Empire-San Diego
     County Deserts-San Diego County Mountains-San Diego County
     Valleys-San Gorgonio Pass near Banning-Santa Ana Mountains
     and Foothills.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...Zuber

NWS San Diego (SGX) Office