499
FXUS66 KSGX 030331
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
831 PM PDT Thu May 2 2024

.SYNOPSIS...
Periods of low clouds and fog are expected each day west of the
mountains, most widespread in the nights and mornings. A weather
system passing to our north will increase cloud coverage for inland
areas this weekend. That system will also bring gusty winds to the
mountains and deserts, cooler conditions, and periods of showers to
areas over and west of the mountains. Drier and warmer conditions
are expected through the middle of next week.

&&

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

.Evening Update...
The marine layer stuck tight near parts of the coast today with
some poor unfortunate souls trapped under the thick cloud deck for
much of the day, while areas near Carlsbad and Encinitas reported
some clearing, albeit only for a half hour or so. Friday looks to
be a similar day across Southern California, with a bit better
clearing by the afternoon for those under the sea and at the
coast, per latest HREF guidance.

No significant changes to the forecast are expected for the
weekend. Colors of the wind will be the most significant impact
with this late season system, so wind advisories have been placed
for portions of the mountains into the deserts. There is a
moderate to high chance in seeing winds in excess of 45 MPH for
these areas by Sunday afternoon and evening, as well as winds over
20 MPH closer to the coast. Be careful if voyaging in your car
(or canoe).

A trough looks likely to weakly hang on into next week. Snow
White will start to serenade the birds, bunnies, and deer by next
week as sunnier and warmer weather returns to the region. Breezy
west winds will occur each day across the mountains and deserts
near 20-30 MPH at times. Overall, nice weather for outdoor
activities such as apple picking...

.Previous Discussion (139 PM Thursday)...
As of 1 PM this afternoon, low clouds have been slow to clear.
The Inland Empire is finally seeing some sunshine, but most of the
coast, Orange County, and western valleys in San Diego County are
still under the cloud deck. The trend is for clearing to occur in
the valleys, but clouds could stick along some beaches all
afternoon. Low clouds are expected to spread into much of the
coastal basin overnight into Friday morning and again Friday night
into Saturday morning.

A low pressure system will move into the Pacific Northwest Saturday,
before digging south in the Great Basin Sunday. This will increase
onshore flow for Southern California this weekend and as a result
cloud coverage (especially for the valleys and mountains) will be
more persistent, high temperatures will take a dip, winds will
increase, and areas of showers are expected. Periods of gusty
southwest to west winds over the mountains, through passes, and into
the deserts will be the main weather hazard. Winds will begin to
increase Saturday afternoon, peak Saturday night into Sunday, before
slowly tapering off Sunday night into early Monday. Peak gusts of 55
to 65 mph are expected on the desert mountain slopes, through
passes, and into portions of the deserts.

Periods of light precipitation are expected for places in and west
of the mountains. Coverage of the precipitation will be showery,
with best chances in the mountains and 15-25 percent elsewhere. This
is a fast moving system and current timing has the bulk of the
shower activity occurring Saturday night into Sunday morning.
Rainfall totals of a 0.15 inches or less are expected for the coast
and valleys with up to 0.25 inches of rain for the coastal mountain
slopes. A trace of snow is possible above 7500 ft.

High temperatures Friday will be near to slightly above average.
Cooler conditions are expected Saturday, with further cooling
expected on Sunday. On Sunday highs will be 10 to 15 degrees below
average for inland areas, up to 20 degrees below average in the
mountains. Monday will be dry and much warmer, around 5 degrees
warmer at lower elevations to 8 to 12 degrees warmer for the
mountains with not much change for Tuesday and Wednesday, generally
a few to around 5 degrees below average.

&&

.AVIATION...
030330Z...Coasts/Valleys...BKN-OVC low clouds will continue to
expand this evening and cover most areas by 08Z Fri with bases 1300-
2000 ft MSL and tops to 2500 ft. Higher terrain will be obscured at
times. Most VIS below the clouds will be unrestricted, but local VIS
3-5 miles in BR will occur in the valleys 06Z-18Z Fri. Clearing will
be slow Fri, mostly 16Z-19Z in the valleys and 18Z-21Z near the
coast, with areas of BKN clouds continuing at the beaches Fri
afternoon. Stratus will spread inland again Fri evening with
slightly higher bases.

Mountains/Deserts...Clear skies with unrestricted VIS will continue
through Fri evening.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday
morning. Gusty west to northwest winds late Saturday through Sunday
evening are likely to generate hazardous boating conditions,
especially in the outer waters (30-60 NM from the coast). Current
projections for strongest winds are on Sunday when gusts could be 25-
30 knots near San Clemente Island with a few gusts 20-25 knots near
the coast.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from 3 PM Saturday to 5 PM PDT Sunday for Apple
     and Lucerne Valleys-Riverside County Mountains-San
     Bernardino County Mountains-San Diego County Deserts-San
     Diego County Mountains-San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...Maxwell