519
FXUS66 KSGX 100421
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
921 PM PDT Sat May 9 2026

.SYNOPSIS...
A warming trend will continue through through Monday, with a
shallower marine layer. Night and morning low clouds will be
restricted to the coast areas and adjacent valleys through this
period. Temperatures will peak on Monday around 10 to 20 degrees
above normal for inland areas with areas of moderate to high heat
risk. A cooling trend with a deepening marine layer will return
by the middle and end of next week as an area of low pressure
approaches the West Coast.

&&

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

...New Aviation Discussion for 06z TAF Package...

The marine layer continues to thin as inland extend was a bit less
this morning than yesterday morning. Low clouds should slowly
dissipate after sticking to the Orange County beaches currently.
High pressure off the coast will begin to build through Monday,
which will suppress the marine layer even further. This will keep
low clouds and fog within 10-15 miles of the coast. This system
will also bring a warming trend to the region through Monday. High
temperatures will increase a couple degrees again on Sunday with
greater warming on Monday. By Monday, model guidance is in fair
agreement with high temperatures reaching 105 to 110 degrees
across the lower deserts and 95 to 100 degrees across the Inland
Empire. Heat alerts have been issued for these areas, so please
take breaks and drink fluids if you are outdoors for long periods.
Cooler weather will occur at the coast with a mix of clouds and
sun.

The area of high pressure will move east as low pressure system
moves closer to California and Oregon. Models are still struggling
with the exact path of this system, but confidence is high that
this will bring a troughing pattern over the area, leading to
cooler weather. By Tuesday, temperatures will drop about 5 degrees
across the deserts and coast, up to 10 degrees for inland valleys.
Inland areas will cool again into Wednesday as the system moves
close to the region. Mountains and deserts can also expect
increasing southwest and west winds near 25-45 MPH. There
continues to be slight model differences by the latter part of
next week. This will lead to temperatures near to slightly above
average with continued dry weather expected.

&&

.AVIATION...
100415Z...Coast/Valleys...Low clouds based 1000-1500ft MSL have
begun to move inland, which will fall closer to 700-1000ft MSL
around 08-10z. Clouds will filter in to 15-20mi inland through
Sunday morning. Only a 20% chance for a CIG at KONT between 12-15z
Sun. VIS 4-6SM at times for elevated coastal sites and inland
valleys through the I-15 corridor. VIS down to 0-3SM and patchy fog
through eastern valleys and in parts of the Inland Empire near gaps
in elevated coastal terrain. Clouds may lift back above 1000ft MSL
after 14-15z Sunday before quickly scattering out by 16-17z. Low
clouds return again Sunday evening after 01z Mon with bases 600-
900ft MSL.

Mountains/Deserts...SKC and VFR through Sunday.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 10 AM to 8 PM PDT Monday for San Bernardino
     and Riverside County Valleys-The Inland Empire.

     Extreme Heat Warning from 10 AM Sunday to 8 PM PDT Monday for
     Coachella Valley-San Diego County Deserts-San Gorgonio Pass
     near Banning.

PZ...None.

&&

$$

PUBLIC...SS
AVIATION/MARINE...Zuber