Fountain Valley, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

405
FXUS66 KSGX 091020
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
320 AM PDT Mon Jun 9 2025

.SYNOPSIS...
Generally seasonal weather will prevail for the next week. High
pressure to the south will bring warming through Tuesday,
followed by slow cooling through Friday, then warmer inland for
next weekend. For early this week and for next weekend, night and
morning coastal low clouds will spread only into the western
valleys with the spread into the valleys a little greater for
Wednesday through Friday.

&&

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

.SHORT TERM (Today through Wednesday)...
A weak upper level low pressure system will move inland through
southern California today. High pressure to the southwest will
expand into southern California for Tuesday and Wednesday. A weak
low pressure system moving inland to the north will strengthen
the onshore flow slightly on Wednesday.

High temperatures will warm for today and Tuesday, then cool
slightly for Wednesday. High temperatures on Tuesday will be as
much as 5 to 10 degrees above average for the mountains, inland
valleys, and high desert. High temperatures on Tuesday will range
from around 70 near the coast to the mid 80s to mid 90s for the
Inland Empire with 105 to 110 for the lower deserts.

Through Tuesday, the marine layer will decrease in depth to around
1500 feet. Night and morning coastal low clouds will spread inland
into the western valleys with limited afternoon clearing near the
coast. The marine layer may begin to deepen slightly on Wednesday.

&&

.LONG TERM (Thursday through Sunday)...
The low pressure system moving inland to the north may weaken the
high pressure across southern California for Thursday and Friday
with a slow cooling trend. The marine layer will deepen to around
2000 feet with night and morning coastal low clouds spreading
farther inland into the valleys. With the cooling, high
temperatures on Friday will be mostly a few to around 5 degrees
above average, into the mid 80s to lower 90s for the Inland Empire
with 105 to 110 for the lower deserts.

For next weekend, onshore flow will begin to weaken with high
pressure to the south expanding into southern California. There
will be a warming trend for next weekend with high temperatures
for next Sunday 5 to 10 degrees above average for inland areas.
High temperatures for next Sunday for the Inland Empire will be
mostly in the 90s with 108 to 112 for the lower deserts. The
marine layer will become a little shallower, but with night and
morning coastal low clouds still spreading inland into the western
valleys.

&&

.AVIATION...
090930Z....Coast/Valleys...Low clouds with bases around 700-1200
feet MSL with tops to 1800 feet will reach into western and southern
parts of the Inland Empire through 14Z. Bases will lift and clouds
will clear to the coast by 18-19Z, but with only partial and/or
intermittent clearing at immediate coast. Low clouds push inland
after 01Z tonight into Tuesday, but not as far inland as this
morning. Bases would be around 500-1000 feet MSL with some vis
reduced over higher coastal terrain.

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

&&

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

&&

.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