049
FXUS66 KSGX 042035
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
135 PM PDT Fri Jul 4 2025

.SYNOPSIS...
High temperatures near average with night and morning low clouds
closer to the coast can be expected through Monday. High pressure
over the Desert Southwest will build into the region by Tuesday
into later next week, bringing in hotter weather for inland areas.

&&

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

.SHORT TERM (Through Monday)...
A broad trough over California and Oregon continues to push inland
this afternoon. This pattern will stick around into next Monday as
a cutoff low forms closer to the Bay Area by Sunday and Monday.
The presence of these features will help to keep temperatures
near average for early July with 70s and 80s across the mountains
and coastal regions with highs in the 90s across the high desert
and Inland Empire. The marine layer depth will generally remain
unchanged with low clouds moving in up to around 15 miles inland
each night and retreating each morning. Onshore winds will be
strongest for the San Gorgonio Pass and high desert regions this
afternoon and evening with a moderate to high chance of seeing
wind gusts over 30 mph, locally over 45 mph along Interstate 10
north of Palm Springs.

&&

.LONG TERM (Tuesday into next week)...
The trough mentioned above will keep an area of high pressure over
the Desert Southwest at bay over the next few days. Models suggest
this to not last as the area of high pressure is expected to
strengthen over Arizona, moving closer to SoCal by Tuesday. This
will increase temperatures a few more degrees than what we will
have seen over the holiday weekend. Ensemble models continue to
show the system growing and expanding over much of our region by
Wednesday through at least Friday, prompting a the first notable
heat wave of the summer. Low level monsoonal moisture will begin
to move into the region by Tuesday and Wednesday. Though the
chance for any storm activity remains below 10 percent, increasing
moisture will lead to increases in humidity throughout the
region. Those without any sufficient cooling measures or having to
work outside during this time into the end of the week will need
to take precautions to stay cool.

More notable warming will take place by Wednesday and Thursday
with high temperatures increasing to 5 to 10 degrees above normal.
Chances for 100 degree or greater temperatures are high across the
IE and the high desert, with closer to 50-70% for some inland
valleys/foothills across San Diego County such as Ramona and Pine
Valley. Highs over 115 across the lower deserts still remains
somewhat in question as higher humidity can act to suppress the
hottest, dry air that comes with large areas of high pressure near
600 dm. It will still be hot and humid across this region, but how
much so still remains uncertain. Ensemble models show fair
agreement in a subtle weakening of the high by Friday, which may
give a weak onshore push of cooling west of the mountains. Some
models continue to a depict the night sticking around into next
weekend, which leads to higher confidence that the heat will stick
around as we head into mid July.

&&

.AVIATION...
042000Z....Coast/Valleys...Satellite shows low clouds have
completely cleared off the coast, with sunny skies and VFR
prevailing through the evening. Low clouds with bases 900-1300ft MSL
redevelop and move inland after 03z tonight, pushing up to 10-15
miles inland. Possible VIS reductions down to 2-3SM near coastal
mesas and in western valleys. Clearing of low clouds back to the
coast will occur quickly Saturday morning, by 16-17z. VFR prevailing
for Saturday afternoon and evening.

VIS restrictions (2-5SM) will be possible in FU associated with
fireworks this evening, especially in Orange County and western IE.
Localized spots may briefly fall to 1SM below 1000ft MSL.

Mountains/Deserts...Sunny with mostly unrestricted VIS through
Saturday. Locations near fireworks displays may briefly see reduced
VIS due to FU generally below 1000ft MSL.

&&

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

&&

.BEACHES...
Southerly swell (190 degrees) of 3 to 4 feet at 15-17 seconds will
generate elevated surf of 4-6 ft with sets to 7 ft along south
facing beaches through Sunday. In addition, strong rip and longshore
currents expected at all beaches through Sunday. A Beach Hazards
Statement is in effect and contains more information. The period
will begin to lower on Sunday, but swell will remain elevated into
Monday.

&&

.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 Sunday evening for Orange County
     Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

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