849
FXUS66 KSGX 051131
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
430 AM PDT Fri Jun 5 2026

.SYNOPSIS...
Warm today with high temperatures a few degrees above normal.
Cooler over the weekend with more widespread marine layer low
clouds. Elevated southwest to west winds during the afternoon and
evening through the weekend. Minor daily temperature fluctuations
Monday through Thursday of next week, with the potential for more
significant warming late in the week. Night and morning low clouds
will continue for the coastal areas and valleys.

&&

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

...Updated Aviation and Marine discussions...

Marine layer low clouds have filled in over the coastal areas and
spread into inland Orange County and parts of the San Diego County
Valleys, with clear skies elsewhere. Low clouds will spread
slightly further inland through sunrise, potentially reaching the
far west parts of the Inland Empire, before clearing back to the
coast by late morning. Weak upper level ridging remains over the
region today, bringing another warm day with high temperatures
in the low to mid 70s along the coast, upper 70s to low 80s for
inland Orange County and the western valleys, mid 80s to low 90s
in the inland valleys, 80s in the mountains, upper 90s in the high
desert, and around 105-108 in the low deserts.

An upper level low currently off the coast of British Columbia
will move southeast into the Pacific Northwest and amplify into
Saturday, with a reinforcing low following a similar path Sunday
into Monday. This will bring cooling across the region into the
weekend with highs lowering to a few degrees below normal by
Sunday. The marine layer deepens each night with low clouds and
patchy fog spreading further inland, potentially covering much of
the inland valleys by Sunday morning. This will also generate
breezy southwest to west winds in the mountains and deserts where
gusts will be near 35-45 mph during the afternoons and evenings,
strongest on Saturday.

While troughing remains around through the middle of the week, the
upper trough becomes less amplified, allowing for minor warming
across Southern California. Temperatures fluctuate slightly each
day, but in general remain within a few degrees of normal. The
marine layer becomes more shallow for less widespread night and
morning low clouds. Ensembles remain in fairly good agreement with
some form of troughing through Wednesday. By Thursday, around 55%
of the members keep the trough over the western US, while the
remaining members are more progressive and have the trough
shifting eastward, allowing some ridging to move in from the west.
This continues into Friday and Saturday, though as we get later
into the week the upper ridge becomes the slightly more dominant
solution, comprising around 58% of the ensemble space. The trough
lingering would result in a continuation of cooler weather with
highs around normal, while the ridging solution would result in
more warming and less low clouds as we head into the end of the
week.

&&

.AVIATION...
051130Z...Coast/Valleys...Low clouds based at 1200-1600 feet MSL
with tops to 1800 feet and vis 4-6SM along inland edge of clouds
will cover coastal areas into western valleys, but only barely into
western and southern corners of the Inland Empire this morning.
Scatter out 16-19Z, but the immediate coast will struggle to clear
fully or for any long duration. Low clouds will push inland after
00Z and spread more fully inland overnight into Saturday.
Bases/tops/vis will trend slightly higher.

Mountains/Deserts...Expect clear skies and VFR conditions today,
with increasing clouds above 20000 feet tonight. Southwest-west
winds will increase in the mountains and deserts with gusts reaching
30-40 knots after 21Z. MOD up/downdrafts and pockets of LLWS in lee
(north and east) of mountains.

&&

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

&&

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

&&

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

&&

$$

PUBLIC...SS
AVIATION/MARINE...MM

NWS San Diego (SGX) Office