San Clemente, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

815
FXUS66 KSGX 291616
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
916 AM PDT Tue Apr 29 2025

.SYNOPSIS...
Fair and spring-like weather will prevail this week, with coastal
low clouds and fog during the nights and mornings, along with
breezy afternoons and evenings in parts of the mountains and
deserts. This weekend, a low pressure trough will bring much
cooler, cloudier, and windier weather with some showers. A
gradual and tepid warming and drying trend follows next week.

&&

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

What happened to the coastal low clouds? Only a few patches
developed overnight. Our best guess is there was a weakened
marine inversion combined with some weak offshore flow. This on
the backside of the low pressure trough taking forever to move
completely out of our region. Today we get a fleeting ridge of
high pressure aloft, which we`ll feel with mostly sunny skies and
higher temperatures. Although there is some residual moisture at
mountain top level that will produce quite a few cumulus clouds
over the mountains today. A weak low pressure trough develops
Wednesday and Thursday right over SoCal. It will serve to bring
cooler weather by a couple degrees, and also help rebuild the
marine layer seemingly into a coastal low cloud forecast we can
count on. There is also some instability over the high desert
indicating some remotely possible thunderstorms Thursday, which
we`ll keep an eye on. Breezy onshore winds will increase through
mountain passes and into deserts each afternoon and evening.
Isolated pockets, such as through and east of the San Gorgonio
Pass, should get gusts at or above 40 mph. Another fleeting ridge
on Friday brings slightly warmer weather and slightly less coastal
cloudiness. Then a big trough develops and deepens as it arrives
in SoCal Saturday. Probably the biggest impact will be strong
winds in all areas, but particularly in the mountains, deserts and
coastal waters. It will also bring cold air, destabilizing the
atmosphere, and not a lot of moisture but enough for showers. And
snow showers for the mountains as the snow level drops quickly on
Sunday (currently showing down to around 5,000 feet). There won`t
be a lot of precipitation, but some. While confidence is high in
the much cooler weather and strong winds, confidence is lower in
the precipitation amounts. Confidence is growing in the timing of
the arrival. Saturday night through Sunday looks like the
stormiest time. Less confidence on when the storm departs on
Monday...ish. Tis the season for closed low pressure systems that
give forecasters fits, but this upcoming system doesn`t look as
capricious as usual. Next Monday or Tuesday a warming and drying
trend appears to get underway.

&&

.AVIATION...
291600Z....Coasts/Valleys...Patchy BKN-OVC clouds with bases of 1500-
2000 ft MSL possible through 17Z. BKN-OVC clouds will return to the
coast 01 to 04Z Wed. Coverage is expected to be more widespread
tonight into Wed, filling in the western valleys. Bases will be in
the 600-1000 ft range. Vis restrictions are expected where low
clouds intersect higher coastal terrain. Low confidence (25 percent)
of low clouds reaching KONT. If low clouds did reach KONT, would
occur after 10Z Wed. Low clouds will scatter out 16-18Z Wed.

Mountains/Deserts...Mostly clear skies with unrestricted VIS will
prevail through Wed morning.

&&

.MARINE...
No hazardous marine conditions are expected through Friday. Gusty
winds will develop over the coastal waters this weekend, with
strongest winds Saturday night and Sunday. Peak gusts of 25 to 32 kt
expected. Gale force winds are possible, with a 30 percent chance of
winds reaching at least 34 kt in the outer coastal waters near
San Clemente Island Saturday night into Sunday morning.

&&

.BEACHES...
Elevated surf of 3 to 6 feet with sets to 7 feet will occur through
Wednesday. Highest surf will occur on south facing beaches today.
Strong rip currents are expected.

&&

.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 Wednesday evening for Orange
     County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...MM
AVIATION/MARINE/BEACHES...CO