332
FXUS66 KSGX 101026
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
326 AM PDT Tue Jun 10 2025

.SYNOPSIS...
High pressure to the southwest will bring warming for the coast
and valleys followed by slow cooling of around 5 degrees for
Wednesday through Friday. High pressure to the south will bring
around 5 degrees of warming for the weekend followed by slow
cooling for early next week. Night and morning coastal low clouds
will continue to spread into portions of the valleys, then become
patchier and not spread as far into the valleys for the weekend
as the marine layer becomes shallower.

&&

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

.SHORT TERM (Today through Thursday)...
The marine layer is still around 2000 feet deep with coastal low
clouds extending inland across much of the San Diego County
valleys and into southern and western portions of the Inland
Empire. The marine layer will remain around 1500 to 2000 feet deep
through Thursday with night and morning coastal low clouds
spreading inland into portions of the valleys.

High pressure to the southwest will bring warming for the coast
and valleys today with the lower deserts a few degrees cooler.
High temperatures for today will be near average for the coast to
as much as 5 to 10 degrees above average for the mountains and
high desert. High temperatures for today will range from the mid
60s to lower 70s near the coast to the mid 80s to mid 90s for the
Inland Empire with 105 to 110 for the lower deserts.

Low pressure off the West Coast will bring slight weakening of the
high pressure aloft over southern California and slight
strengthening of the lower-level onshore flow with cooling of
around 5 degrees for Wednesday through Friday.

&&

.LONG TERM (Friday through Monday)...
There will be slight additional cooling on Friday with around 5
degrees of cooling for Wednesday through Friday. High temperatures
on Friday will be mostly within a few degrees of average for the
coast and valleys with the deserts around 5 degrees above average.
High temperatures on Friday will range from around 70 near the
coast to the 80s and lower 90s for the Inland Empire with 104 to
108 for the lower deserts.

High pressure to the south will bring warming for the weekend of
around 5 degrees with Sunday high temperatures mostly 5 to 10
degrees above average. High temperatures on Sunday will range from
the lower 70s near the coast to the 90s for the Inland Empire with
108 to 112 for the lower deserts. Monday will be a few degrees
cooler.

Higher-resolution WRF runs using GFS and ECMWF boundary conditions
show patchier coverage of night and morning coastal low clouds for
the weekend with coverage not extending inland much past the far
western valleys as the marine layer becomes shallower.

&&

.AVIATION...
100930Z....Coast/Valleys...Coastal low clouds will nearly fill the
coastal basin by 14Z. Bases will be 800-1200 feet MSL with tops to
1800 feet. Vis reduced 1-5SM inland and over higher coastal terrain.
Scatter out 16-17Z inland and 18-20Z at the coast, but very little
if any clearing is expected along immediate coast. Low clouds to
gradually move into western valleys after 02Z and overnight into
Wednesday with similar timing, bases, vis and extent of coverage.

Mountains/Deserts...Mostly clear skies and unrestricted VIS today
and tonight.

&&

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

&&

.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...17
AVIATION/MARINE...MM