889
FXUS66 KSGX 160536
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1036 PM PDT Mon Jun 15 2026

.SYNOPSIS...
Above average high temperatures early this week will cool to below
average during the latter half of the week through the weekend.
Coastal low clouds will spread farther into the valleys during the
latter half of the week each night and morning as the marine
layer slowly deepens.

&&

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

...New Aviation Discussion...

Coastal low clouds cleared on schedule this morning, but have been
persistent to hang at the immediate coast in most of San Diego
County. Monsoon moisture over the mountains and deserts is being
manifest by mid level clouds, including cumulus clouds over the
mountains. Isolated showers are expected along the Baja spine this
afternoon, with only a ghost of a chance just north of the
border (at noon, there were legit thunderstorms in and around
Yuma, AZ). Very similar weather will continue through Tuesday,
with similar marine layer and monsoon influences. The upper level
pattern shows a very weak trough over SoCal underlying a strong
ridge over the Pac NW (producing some record high temps in
Portland and Seattle), and no discernible change through
Tuesday night. The marine layer will continue more or less at its
current depth of about 1000-1500 feet deep through Tuesday, which
will preclude low clouds and fog from entering the Inland Empire.
Temperatures will remain just a few degrees above seasonal
averages through Tuesday. Monsoon moisture hangs around for one
more day, so you`ll continue to see some mid level cumulus and
altocumulus clouds, especially over the mountains Tuesday
afternoon. Very weak low pressure aloft Wednesday helps deepen
our marine layer and sweeps the monsoon moisture away. A trough
of low pressure begins to develop off the West Coast around
Thursday and deepens Friday and Saturday as it advances through
California. That will flip temperatures from a few degrees above
average to a few degrees below on Wednesday and especially
Thursday. The marine layer will respond by deepening Wednesday
morning, and extending the nocturnal coastal clouds farther inland
each night and morning into Saturday. There should be stronger
onshore winds through mountain passes and into deserts each
afternoon and evening, looking strongest on Friday when gusts of
40-50 mph are likely through the wind-prone mountain passes like
San Gorgonio Pass. After the trough passage on Saturday, weak high
pressure returns Sunday, which will reverse the temperature and
marine layer trends. In other words, a modest warming trend and
less extensive coastal clouds in a shallower marine layer come
Sunday.

&&

.AVIATION...
160540Z...Coast/Western Valleys...Patchy low clouds along the San
Diego Co coastline will gradually pushing north into OC after 09Z
and inland to 10-15 miles from the coast overnight. Local areas of
vis 3-6 SM will be isolated to higher terrain in coastal/western
valley areas. Low clouds will begin their retreat west after 15Z,
clearing offshore 17-18Z for most locations, with better clearing
than this afternoon expected. Similar based low clouds move back
ashore after 03Z Wed, with similar inland extent.

Mountains/Deserts...VFR conditions are expected through the TAF
period, with the occasional SCT-BKN clouds 12-15k feet MSL. Cumulus
around 10000 feet MSL over mountain areas through 02Z. Breezy
westerly winds gusting 25-30 kts through mountain passes and into
deserts again Tuesday after 19Z through about 06Z Wed.

&&

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

&&

.BEACHES...
Elevated surf and strong rip currents continue through Friday. Surf
of 3-6 feet with sets to 7 feet are expected at south-facing
beaches. Surf for southern San Diego County 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...17
AVIATION/MARINE/BEACHES...CSP

NWS San Diego (SGX) Office