Chula Vista, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

162
FXUS66 KSGX 050414
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
914 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 for Tuesday
into later next week, bringing hotter weather for inland areas.

&&

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

This evening...The marine layer is a little shallower than
yesterday afternoon at about 2000 ft. At this hour, low clouds
are forming and increasing in coverage along the San Diego County
coast. High-resolution models indicate that low clouds and fog
will make it into Orange County and spread 10-15 miles inland by
sunrise before clearing to the coast by around 11 am. High
temperatures this afternoon were generally near or a few degrees
below seasonal averages even in the lower deserts.

From previous discussion...
A closed upper low continues to move inland over the Pacific
Northwest. This pattern will stick around into Monday as a closed
upper low forms near the Bay Area by late Sunday. 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.

The low mentioned above will keep an area of high pressure over
the Desert Southwest at bay over the next few days. Models suggest
this will 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 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 high sticking around into next
weekend, which leads to higher confidence that the heat will stick
around as we head into mid July.

&&

.AVIATION...
050300Z....Coast/Valleys...Low clouds with bases 900-1200ft MSL have
begun to redevelop and move gradually onshore this evening, and will
up to 10-15 miles inland by 11Z tonight. Low clouds will bring VIS
reductions down to 2-4SM on coastal mesas and in western valleys.
Clearing of low clouds back to the coast will occur quickly Saturday
morning, by 16-17Z. VFR prevails Saturday afternoon and evening,
before patchier low clouds based 600-1000 ft MSL redevelop and move
ashore late in the evening, likely after 06Z Sun.

VIS restrictions (2-6SM) will be possible in FU associated with
fireworks this evening, especially in Orange County and western IE.

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 are 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...PG
AVIATION/MARINE/BEACHES...CSP