Alpine, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

644
FXUS66 KSGX 250037
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
537 PM PDT Sun May 24 2026

.SYNOPSIS...
Near average temperatures today with below average temperatures
expected Monday through midweek. Low clouds will spread into the
valleys each night and morning, lingering into the afternoon at
times along the coast. Increased westerly winds expected Tuesday
through potentially Thursday for the mountains and deserts. Patchy
drizzle or light rain possible west of the mountains each night
and morning from Monday night through Thursday morning.

&&

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

...Updated aviation section for 00Z TAF package...

Low clouds in the coastal basin are making their retreat to the
coast with clearing skies behind and to the east of the mountains.
Clearing at the coast will be short lived with the marine layer
expected to move back in later this afternoon and once again
filling into the coastal basin late tonight into the early Monday
morning. High temperatures will be near to just below the seasonal
average as an upper level low moves from just off the coast and
to the east Monday.

As low pressure decreases at the surface through Thursday,
temperatures will continue to cool and the marine layer will deepen.
This will increase chances for patchy drizzle west of the mountains
beginning Monday night through Thursday morning and bring daily
highs 10-15 degrees below average for the Inland Empire, mountain
areas, and deserts by Thursday afternoon.

An upper level trough is expected to slide down the coast Tuesday
through Thursday before moving out to the northeast Friday. This
trough will produce gusty onshore winds in the mountains and
deserts, especially in the desert mountain slopes and passes. The
strongest winds are expected Tuesday and Wednesday in the afternoons
evenings with wind gusts around 35-55 mph in desert areas, with
isolated gusts up to 60 mph through the passes.

Temperatures will begin to increase Friday, reaching near the
seasonal average by the weekend.

&&

.AVIATION...
250000Z...Coast/Valleys...A patch of low clouds 2000-2500 ft MSL is
lingering along the south SD County coast. While some scatter out in
this area is briefly possible, its likely that clouds will begin to
spread into the remainder of coastal regions this afternoon, then
into the coastal basin by 10Z or so. The locations that are most
likely to see bases below 2000 ft are near mountain foothills and
far inland valleys (70-80 percent chance of occurrence). Low clouds
expected to clear 18-20Z Mon, with only partial and intermittent
clearing along the coast, especially in south San Diego County.

Mountains/Deserts...Mostly clear with VFR conditions.

&&

.MARINE...
Breezier westerly winds with gusts near 21 kt likely Tuesday and
Wednesday afternoon and evening in the outer coastal waters by San
Clemente Island. Otherwise, no hazardous marine conditions are
expected through Friday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from 3 PM Tuesday to 5 AM PDT Thursday for
     Riverside County Mountains-San Diego County Deserts-San
     Diego County Mountains-San Gorgonio Pass near Banning.

     Wind Advisory from 3 PM Tuesday to midnight PDT Tuesday night
     for Apple and Lucerne Valleys.

PZ...None.

&&

$$

PUBLIC...Villafane
AVIATION/MARINE...CSP