277
FXUS66 KSGX 252023
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
123 PM PDT Thu Jun 25 2026

.SYNOPSIS...
Windy over the mountains and into the deserts, well below average
temperatures across Southern California, and a deeper marine layer
can be expected this weekend. Areas of drizzle are possible, with
Saturday morning as the most likely day. Conditions will gradually
warm into next week.

&&

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

A unseasonable trough of low pressure is expected to dig into the
Great Basin this weekend. This will increase the onshore pressure
gradient, resulting in stronger westerly winds on the desert
mountain slopes into the deserts, well below average temperatures,
and a deeper marine layer. By Sunday, highs are expected to be 7 to
9 degrees below average at the coast and low deserts and 15 to 20
degrees below average in the valleys, mountains, and High Desert.
There is also a potential for patchy drizzle west of the mountains,
most likely on Saturday morning.

Winds will begin to increase today on the desert mountain slopes and
in the deserts and strengthen into Saturday. Wind gusts Friday will
be 35 to 50 mph, combined with relative humidity 7 to 15 percent in
the deserts will create periods of near critical to locally critical
fire weather conditions in the deserts. For more information on fire
weather concerns, see the Fire Weather section below. Winds are
expected to peak in strength on Saturday afternoon and evening, with
peak gusts 50 to 65 mph with locally higher gusts possible below the
San Gorgonio Pass. Winds will decrease Sunday into next week.

Global ensembles are indicating broad scale weaker troughing may
linger into the end of next week. Even with the lingering troughing,
heights will rise leading to a gradual warming. About 27 percent of
ensemble guidance is indicating a ridge may begin to build back in
by next weekend. By next Thursday, highs will be 3 to 7 degrees
below average. Additionally, the weak troughing will maintain a
deeper marine layer into at least the middle of next week.

&&

.AVIATION...
251730Z...Coast/Valleys...Patchy low clouds to persist along
beaches, but coastal airports will be scattered out through the
afternoon. Low clouds around 2000 feet MSL will push ashore around
01Z and eventually fill the coastal basin again overnight. Vis
reduced inland 1-5SM with partial terrain obscuration 2000-3000 feet
MSL. Scatter out Friday 16-18Z.

Mountains/Deserts...Mostly clear and VFR conditions expected through
Friday morning, except for coastal slopes shrouded in fog below 3500
feet MSL 10-15Z Friday. West-southwest winds 25-35 kts gusts to 45
kts through mountain passes and locally into deserts after 21Z,
decreasing a little early Friday morning. Occasional MOD
up/downdrafts in lee of mountains.

&&

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

&&

.BEACHES...
A long-period south swell will continue to bring surf of 3 to 6 feet
today with the highest surf on south facing beaches. See the Beach
Hazards Statement for details.

&&

.FIRE WEATHER...
Lowest daytime humidity for the deserts will fall to 7 to 15 percent
Friday during the afternoon and early evening. That low humidity
combined with southwest to west winds gusting 35 to 50 mph during
the afternoon and evening will bring near critical to locally
critical fire weather conditions for the deserts onto the desert
slopes of the mountains during the afternoon and early evening today
and Friday. Humidity will improve to near 20 percent by the time the
winds peak in strength on Saturday afternoon. Peak wind gusts of 50
to 65 mph, locally higher possible below the San Gorgonio Pass,
expected Saturday. Winds will weaken Sunday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 10 PM PDT this evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Wind Advisory from 11 AM Friday to 5 AM PDT Sunday for Apple and
     Lucerne Valleys.

     Extreme Heat Warning until 8 PM PDT this evening for San Diego
     County Deserts.

     Wind Advisory from 5 PM Friday to 11 AM PDT Sunday for San Diego
     County Deserts.

     Wind Advisory from 11 AM Friday to 5 PM PDT Sunday for San
     Gorgonio Pass near Banning.

PZ...None.

&&

$$

PUBLIC/FIRE WEATHER...CO
AVIATION/MARINE...MM

NWS San Diego (SGX) Office