539
FXUS66 KSGX 021613
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
913 AM PDT Mon Jun 2 2025

.SYNOPSIS...
A low pressure system from the northwest will deepen the marine
layer into Wednesday and bring a chance of showers for the
mountains, deserts, and inland valleys for Tuesday afternoon
through Wednesday afternoon along with a chance of thunderstorms
for Tuesday afternoon and evening and again for Wednesday
afternoon. It will be dry and gradually warmer for Thursday
through next weekend with high temperatures warming from a few to
around 5 degrees below average on Tuesday to around 5 degrees
above average for next weekend. The marine layer will become
gradually shallower for the latter half of the week with night and
morning coastal low clouds not spreading as far into the valleys.

&&

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

.Morning Update...

Low clouds continue to scatter across the valleys with
intermittent clouds lingering near the beaches throughout the
day. It will another humid day out there today, with the morning
sounding showing lowering levels close to saturation with PWAT
values near 1.25 inches. A 575 mb low west of Point Conception
will continue to work its way south and east through today. We
will monitor the potential for showers and thunderstorms across
the region that will be associated with this on Tuesday and
Wednesday. Confidence remains high that the latter half of the
week will be dry and slightly warmer.

.Previous Discussion (325 AM Monday)...

.SHORT TERM (Today through Wednesday)...
An upper level low pressure system centered over southwest Arizona
early this morning will move east and weaken today. A second low
pressure system will move southward off the California today, then
move slowly eastward off the southern California coast on Tuesday,
and then inland across southern California and northern Baja for
Tuesday night and Wednesday.

The higher precipitable water values across the area on Sunday
won`t decrease all that much today, but the atmosphere will be
more stable. Precipitable water values will increase again on
Tuesday, similar to those of Sunday, before gradually decreasing
for the rest of the week. That low pressure system from the
northwest will draw more moisture into the area from the south on
Tuesday and increase the instability for Tuesday into Wednesday.
There is a chance of showers for the mountains, deserts, and
inland valleys for Tuesday afternoon through Wednesday afternoon
along with chance of thunderstorms for Tuesday afternoon and
evening and again for Wednesday afternoon.

A marine layer near 2000 feet deep will deepen for Tuesday into
Wednesday to around 3500 feet for Tuesday night into Wednesday
morning with coastal low clouds extending well inland and onto the
lower coastal mountain slopes.

High temperatures will generally slowly cool through Wednesday
with Wednesday high temperatures a few to around 5 degrees below
average. High temperatures for Wednesday will range from the upper
60s near the coast to the mid 70s to lower 80s for the Inland
Empire with the mid to upper 90s for the lower deserts.

&&

.LONG TERM (Thursday through Sunday)...
Low pressure aloft will weaken for Thursday and Friday with high
pressure aloft strengthening for next weekend. It will be dry with
a gradual warming trend with high temperatures warming from a few
to around 5 degrees below average on Thursday to around 5 degrees
above average for next weekend. With the warming, high
temperatures for next weekend will range from around 70 near the
coast to the mid 80s to lower 90s for the Inland Empire with 104
to 108 for the lower deserts.

The greater spread in the high temperature guidance is for the
valleys due to uncertainty in the marine layer depth. The marine
layer will become gradually shallower for Thursday into next
weekend with night and morning coastal low clouds not spreading as
far into the valleys.

&&

.AVIATION...
021545Z....Coasts/Valleys...Low clouds based at around 800-1000ft
MSL with tops to 1400ft are slowly moving offshore, with clearing at
most coastal sites by 17z with some patchiness lingering along
immediate coast thereafter. A fairly uniform marine layer pushes
ashore after 02Z Tuesday, spreading into the Inland Empire and
inland valleys by 07Z. Bases will be closer to 1500 feet MSL, with
VIS reduced inland. Clearing looks to occur at quickly after 16Z,
but may linger along the coast beyond 18z.

.Mountains/Deserts...VFR prevails and mostly clear skies. Cu based
at 9,000ft MSL over mountains and locally over deserts 18-02Z.

&&

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

&&

.BEACHES...
A long period south swell will bring elevated surf up to 6 to 7 feet
primarily for south and southwest facing beaches through Tuesday
resulting in a higher rip current risk and locally hazardous
swimming conditions. A Beach Hazard Statement is in effect and
contains more information.


&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Tuesday afternoon for Orange
     County Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

UPDATE...APR
PUBLIC...17
AVIATION/MARINE...Zuber