Muscoy, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

174
FXUS66 KSGX 121830
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1130 AM PDT Tue Aug 12 2025

.SYNOPSIS...
Above average temperatures will continue for inland areas through
Wednesday with a gradual cooling expected Thursday through Saturday.
A warming trend will return for early next week. Breezy westerly
winds expected on the desert mountain slopes into the deserts each
afternoon/early evening through this weekend. Night and morning
coastal low clouds will spread farther into the western valleys late
each night for Friday into the weekend as the marine layer
deepens.

&&

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

Areas of moderate to major HeatRisk will continue for the deserts,
with areas of moderate HeatRisk for the mountains. Highs in the
mountains and deserts today will run 5 to 10 degrees above
average for this time of year. West of the mountains, marine layer
low clouds and fog had made it into the western valleys. The
marine layer influence should help moderate temperatures for
Orange County and portions of the San Diego valleys today. At 830
AM, low clouds were starting to very slowly clear from the
valleys. Patches of low clouds may linger along the immediate
coast into the afternoon hours today.

A few degrees of cooling is expected on Wednesday for the mountains
and deserts with more widespread cooling into Thursday as an upper
level trough settles over the West Coast. The trough is expected to
remain in place into early next week. This will result in below
average temperatures for the end of the week along with breezy
westerly winds on the desert mountain slopes into the deserts and
a deeper marine layer.

Early next week the ridge of high pressure to our east may begin to
strengthen and move back towards Southern California. That will
bring another round of warming conditions Sunday through Tuesday.
There remains some uncertainty in the position of the ridge as it
settles over the desert southwest. The overall position of the ridge
will determine how hot it will get and if any monsoonal moisture
will be allowed in our area. Latest ensemble guidance does not have
any precipitable water increases or notable precipitation chances
until at least the end of next week.

&&

.AVIATION...
121500Z...Coasts/Valleys...Low clouds 700-1200 ft MSL are 10 miles
inland, scattering 15-17Z. Best chance for clouds near 800-1200 ft
MSL to stick near the beaches will be closer to San Diego through
the afternoon. Moderate to high confidence in clouds to push back
ashore by 03-05z Wednesday with similar coverage, building 10-15
miles inland once again.

Mountains/Deserts...Mostly clear and VFR conditions continue through
Wednesday.

&&

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

&&

.BEACHES...
Long period (15-16 second) southwesterly (200-220 degree) swell will
bring elevated surf and a high rip current risk through Thursday.
Surf of 3 to 5 feet with local sets 6 to 7 feet.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Warning until 8 PM PDT this evening for Apple and
     Lucerne Valleys.

     Extreme Heat Warning until 8 PM PDT Wednesday for Coachella
     Valley-San Diego County Deserts-San Gorgonio Pass near
     Banning.

PZ...None.

&&

$$

PUBLIC...CO
AVIATION/MARINE/BEACHES...Westerink