752
FXUS66 KSGX 111049
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
349 AM PDT Fri Sep 11 2026

.SYNOPSIS...
Drying and gradual cooling is expected through the weekend with
HeatRisk for most areas below Moderate by the end of the weekend.
Patchy night and morning coastal low clouds will increase in
coverage and spread locally into the western valleys at times for
the weekend into early next week. High pressure to the east is
expected to bring a warming trend for the latter half of next
week.

&&

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

...UPDATED AVIATION DISCUSSION...

.SHORT TERM (Today through Sunday)...
High pressure over southern California will weaken as a low
pressure system moves southward off the British Columbia coast
today and inland through the Pacific Northwest on Saturday. This
will strengthen the onshore flow across southern California with
drier southwest flow aloft. Cooling began to spread inland on
Thursday and that will continue through the weekend. High
temperatures will be a few degrees cooler for most areas for today
and again on Saturday with a little greater cooling for the
valleys of around 5 degrees on Sunday.

High temperatures for today will still be 5 to locally 10 degrees
above average with high temperatures ranging from the upper 70s to
mid 80s near the coast to the 90s for the Inland Empire with 106
to 110 for the lower deserts. While not quite as hot as recent
days, Moderate HeatRisk will continue for the valleys and inland
coastal areas and a Heat Advisory has been issued for these areas
through 8 PM today.

For Sunday, high temperatures near the coast will be near average
with the lower deserts a few degrees above average with the
valleys around 5 degrees below average. High temperatures on
Sunday will range from the mid to upper 70s near the coast to the
upper 80s and lower 90s for the Inland Empire with 102 to 106 for
the lower deserts.

Low temperatures will cool as the atmosphere cools and inland
areas dry with low temperatures on Sunday still a few degrees
above average for the coast into the valleys and around 5 degrees
above average for the mountains and deserts. Low temperatures on
Sunday for the coast and valleys will be mostly in the 60s with a
few of the cooler protected valleys in the mid 50s.

With drying of mid and higher level moisture, patchy night and
morning coastal low clouds will increase in coverage and spread
locally into the far western valleys at times over the weekend as
the marine layer slowly deepens.

&&

.LONG TERM (Monday through Thursday)...
Low pressure near the California will weaken early next week. High
pressure to the east may begin to expand across the area for the
latter half of next week. Temperatures will continue to cool for
early next week with Tuesday high temperatures ranging from the
70s near the coast to the 80s for the Inland Empire with the lower
deserts around 100. This will be followed by a warming trend for
Wednesday through Friday of next week, but with increase spread
in just how much warming may occur. The NBM 50th percentile would
warm temperatures to around average for Friday of next week with
high temperatures for next Friday ranging from the mid 70s to
lower 80s near the coast to the upper 80s and lower 90s for the
Inland Empire with 100 to 104 for the lower deserts. Dry weather
is expected to continue for Monday through Thursday of next week.

&&

.AVIATION...
111100Z...Coast...Patchy low clouds with bases around 600-900 feet
MSL and local vis 3-5SM, lowest on coastal mesas, will continue
through 16Z. Cigs most likely around KSAN. Low clouds to return
after 02Z with more uniform and expansive coverage. Bases around 900-
1200 feet MSL.

Otherwise, SCT clouds above 15 kft and VFR conditions today and
tonight, with cumulus clouds around 10 kft over mountains 19-00Z.

&&

.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...Heat Advisory until 8 PM PDT this evening for Orange County
     Inland Areas-San Bernardino and Riverside County Valleys-
     The Inland Empire-San Diego County Coastal Areas-San Diego
     County Valleys.

     Extreme Heat Warning until 8 PM PDT this evening for Coachella
     Valley-San Diego County Deserts-San Gorgonio Pass near
     Banning.

PZ...None.

&&

$$

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

NWS San Diego (SGX) Office