South Fontana, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

852
FXUS66 KSGX 150007 CCA
AFDSGX

Area Forecast Discussion...CORRECTED
National Weather Service San Diego CA
507 PM PDT Sun Jun 14 2026

.SYNOPSIS...
Fair and benign weather will continue this coming week, with only
subtle variations. Temperatures will continue a little above
average through Wednesday before lower pressure aloft brings
cooler weather later in the week. The marine layer and coastal
cloud coverage will continue similar through Wednesday, before
deepening and extending clouds farther inland Thursday into
Saturday. Expect westerly winds through mountains and into deserts
to become a little stronger during the afternoons and evenings
later this week.

&&

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

...Updated Aviation Discussion Below...

Coastal low clouds cleared relatively quickly this morning, and
even cleared from most beaches completely today. The 12Z sounding
showed the marine inversion this morning a little weaker than in
recent mornings, allowing for a little better mixing between the
humid marine layer and the dry warmer air above it, which led to
the better clearing. Above average sea surface temperatures have
also contributed to the weakening of the marine inversion.
Meanwhile, the tepid monsoon intrusion continues, with a few
cumulus clouds forming over the mountains this afternoon, and
showers along the baja spine not too far south of the border. Our
weather will continue more or less as is through Tuesday. The
upper level pattern shows a very weak trough underlying a ridge
along the West Coast, and no discernible change through
Wednesday. It is June after all, when the polar jet stream heads
north to summer in Canada. The marine layer will continue more or
less at its current depth of about 1000-1500 feet deep, which
will preclude low clouds and fog from entering the Inland Empire.
Temperatures will remain just a few degrees above seasonal
averages through Wednesday. The monsoon moisture, paltry as it is,
will go away completely by Wednesday. Until then you might see a
few mid level cumulus clouds each day through Tuesday, especially
over the mountains during the afternoons. A low pressure trough
begins to develop off the West Coast around Thursday and deepens
Friday and Saturday as it moves through California. That will flip
temperatures from a few degrees above average to a few degrees
below starting Thursday. The marine layer will respond by
deepening, extending the nocturnal clouds farther inland each
night and morning. There should be stronger onshore winds through
mountain passes and into deserts each afternoon and evening.


&&

.AVIATION...
142330Z...Coast/Western Valleys...Low clouds cling to the immediate
coast with a thicker band along coastal San Diego County with bases
around 1300ft MSL. Patchy low clouds will begin to push inland at
the beginning of the TAF period, slowly increasing in coverage over
SD after 06-07Z, spreading inland 10-15 miles and north to OC with
bases 800-1500ft MSL. VIS 0-5SM will be possible in valleys east of
I-15 in SD County and elevated coastal terrain where cigs reach. Low
clouds will begin to retreat after 15Z, clearing inland areas by 16-
17Z and coastal areas after 17-18Z.

Mountains/Deserts...VFR conditions are expected through the TAF
period with mid level clouds AOA 15000ft MSL. Gusty onshore winds
through desert slopes and the San Gorgonio Pass into the Coachella
Valley have brought gusts 25-30 kts. These winds will begin to
gradually weaken around 06-09Z.

&&

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

&&

.BEACHES...
Elevated surf and strong rip currents continue at area beaches
through Friday. Surf of 3-6 feet with sets to 7 feet are expected
at south-facing beaches. San Diego County Surf will be slightly
lower but, hazardous swimming conditions with high rip current and
longshore current risk will still exist. See the Beach Hazards
Statement for more details.

&&

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

PZ...None.

&&

$$

PUBLIC...MM
AVIATION/MARINE...Villafane