Top of the World, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

603
FXUS66 KSGX 122356
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
456 PM PDT Sat Sep 12 2026

.SYNOPSIS...
A cooling and drying trend will occur across the region into the
weekend and early next week. This will be accompanied by a building
marine layer with clouds returning closer to the coastal areas each
night and morning. An area of high pressure may strengthen by the
end of next week, nudging temperatures back above average.

&&

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


...UPDATED AVIATION DISCUSSION FOR THE 00Z TAF PACKAGE...

High pressure continues to weaken over the region today with
stronger onshore flow seen at current observations. This has allowed
for a deepening marine layer, where some places along the coast saw
low clouds and patchy fog earlier this morning. Looking toward the
lunch hour, temperatures a relatively cooler with highs in the 70s
to near 90 west of the mountains. Elevated westerly winds will also
be felt across the mountains and deserts with wind gusts 20-40 MPH.

An area of low pressure off the west coast of British Columbia will
continue to push southward today, eventually moving into the Pacific
Northwest this weekend. This weather pattern will help bring in more
cooler air and greater extent to the marine layer into far western
valleys. We can expect to cool a few degrees each day with breezy
westerly winds across the mountains and deserts each afternoon and
evening. Temperatures will be near average by the weekend, with
highs dipping below average by next Monday and Tuesday.  High
temperatures may stay below 90 degrees for areas west of the
mountains with highs closer to 100 degrees over the Coachella
Valley. Low temperatures will also begin to cool off through early
next week as well with lows in the 50s and 60s along and west of the
mountains and up in the high desert.

High pressure over the Southern Plains may expand further into the
desert southwest by the end of next week. The placement and strength
of this system is still uncertain, but many models are hinting that
another subtle warm up may take place by this time. NBM shows highs
approaching 100 across inland valleys with 70s and 80s closer to the
coast and across the mountains.

&&

.AVIATION...
130000Z...Coasts/Valleys...Low clouds (based around 1400ft MSL) have
stuck near the beaches through the afternoon and have snuck back in
a few miles onshore, bringing intermittent CIGs to KSAN and KCRQ.
Over the next few hours, expecting these marine layer clouds to
surge inland, spreading inland and into Orange County through 03-06z
Sunday. By 06z, marine layer clouds should stretch around 20 miles
inland with overnight bases around 1300-1500ft MSL. There is about a
60% chance that CIGs reach KONT between 11-16z with a ~30% chance to
reach KSBD during this window. VIS reductions limited to higher
inland terrain. Clouds begin to scatter out 16z Sunday morning,
eventually scattering at the coasts around 18z. As with what was
seen today, clouds may linger near the beaches or just offshore into
Sunday afternoon, with a chance for intermittent CIGs to return to
the coastal TAF sites as early as 21-22z Sun.

Mountains/Deserts...S/W winds gusting over 30 kts at times until 06z
Sunday through mountain passes into the deserts. Otherwise, VFR
conditions prevail through Sunday evening.

&&

.MARINE...
West-northwest winds expected to gust up to 20 knots in the outer
coastal waters Sunday afternoon. Otherwise, no hazardous marine
conditions are expected through Wednesday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...Munyan