939
FXUS66 KSGX 030704
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1204 AM PDT Wed Jun 3 2026

.SYNOPSIS...
High pressure aloft will bring warming through Thursday with high
temperatures for inland areas 5 to 10 degrees above average on
Thursday. Coastal low clouds will only extend into the western
valleys for early Thursday and early Friday as the marine layer
becomes a little shallower. A low pressure system moving into the
western states will bring cooling and deepening of the marine
layer for the weekend with coastal low clouds extending onto the
coastal slopes of the mountains early Sunday. This will be
followed by a gradual warming trend for early next week.

&&

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

.SHORT TERM (Today through Friday)...
Subtropical high pressure aloft over the eastern Pacific will
expand across southern California through Thursday, then begin to
weaken on Friday. High temperatures for today will warm as much
as 4 to 8 degrees for the inland valleys and coastal slopes of the
mountains with most areas warming a few more degrees on Thursday.
High temperatures will begin to cool for the valleys on Friday by
a few degrees.

High temperatures on Thursday will be as much as 5 to 10 degrees
above average for the mountains, deserts, and inland valleys with
coastal areas a few degrees above average. High temperatures on
Thursday will range from the lower 70s near the coast to the mid
80s to mid 90s for the Inland Empire with 104 to 108 for the lower
deserts.

Coastal low clouds are expected to spread into portions of the
inland valleys early today. The marine layer is expected to
decrease in depth later today to around 2000 feet with coastal
low clouds only spreading inland into the western valleys for
early Thursday and early Friday.

&&

.LONG TERM (Sunday through Tuesday)...
A low pressure system will move inland into the western states
during the weekend. The greater cooling of high temperatures for
southern California is expected on Saturday with the cooling
continuing through Sunday. High temperatures on Sunday will be a
few degrees below average to around 5 degrees below average for
the inland valleys onto the coastal slopes of the mountains. High
temperatures on Sunday will range from around 70 near the coast
to the upper 70s to mid 80s for the Inland Empire with the lower
deserts around 100.

Model clusters show the growing spread in the high temperature
guidance for early next week are mostly due to differences in the
strength of the low pressure system near the West Coast. Those
that are weaker are warmer for southern California while those
that maintain a stronger low pressure system near the coast are
cooler for southern California. Overall, the guidance shows a
gradual warming trend for early next week.

The marine layer will deepen over the weekend with coastal low
clouds extending inland across most of the valleys for early
Saturday and onto the coastal slopes of the mountains for early
Sunday. The marine layer is expected to begin decreasing in depth
early next week with night and morning coastal low clouds not
spreading as far into the valleys.

&&

.AVIATION...
030430Z...Coast/Valleys...Low clouds based 1500-2000 ft MSL have
redeveloped over coastal San Diego County this evening. Clouds
expand northward and inland overnight, eventually reaching into
portions of the Inland Empire by 12z. 70% chance for cigs at KONT
and 50% at KSBD. Minor vis reductions (4-6SM) for elevated inland
valleys. Scattering to the coastline by 17-18z Wed. Low clouds
return to coastal areas Wed evening with lower bases around 1000-
1500 ft MSL. Less inland extent Wednesday night with clouds
remaining confined to coastal areas and western valleys.

Mountains/Deserts...Mostly clear skies and VFR conditions through
Wednesday evening.
.

&&

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

&&

.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...KW

NWS San Diego (SGX) Office