223
FXUS66 KSGX 282327
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
427 PM PDT Wed Oct 28 2026

.SYNOPSIS...
A subtle cooling trend with cloudier skies and a rainier outlook is
on tap as we head toward the weekend.  The heaviest rainfall is
expected later on Saturday into Sunday. Slightly warmer temperatures
and dry weather is expected by Monday into the middle of next week.

&&

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


...UPDATED AVIATION DISCUSSION...

A weak troughing pattern will continue across the region today into
Thursday. This will bring temperatures near to slightly below normal
with quiet weather. The marine layer will begin to build further in
the days ahead with better chances for low clouds to fill parts
of the coastal basin each night and morning.

A low pressure system currently over British Columbia will move
southward Thursday into Friday, near the coasts of Washington and
Oregon. As it does so, the troughing pattern will become stronger,
bringing in slightly cooler weather and a deeper marine layer. The
marine layer may become saturated enough by early Friday morning
through Saturday morning produce isolated light showers for
coastal areas and western valleys as high-res models are beginning
to suggest, so chances for rain are around 15-25% in the forecast.

A large area of moisture in the form of a subtropical low pressure
system that we have been watching the past few days, continues to
look likely to form off to our southwest Friday into Saturday.
There continues to be model differences on exactly where this
system tracks into the Halloween weekend. Some show the system
moving further north across SoCal, which would give us a more wet
scenario. Others keep the system further south toward San Diego
and into Baja California, which would not be as wet. Both these
tales favor San Diego County receiving the most rain overall.

In terms of timing and how much rainfall we see is still in
question. The heaviest rain may begin as early as Saturday afternoon
starting from west to east, though would not be surprised if this is
delayed toward an evening start. Chances for the heaviest rain
greatly increase later Saturday night into Sunday morning area
wide, with rain showers diminishing Sunday night. NBM shows
chances for weekend rain totals over 1 inch to be near 55-70%
across western San Diego County, as well as all mountain areas
across SoCal. The chances lower near 35-45% for much of Orange
County, the Inland Empire and the desert regions. These chances
and the forecast will likely change some in the coming days, so
please be prepared for wetter than normal Halloween weekend and
keep an eye on the forecast.

Starting Monday into the middle next week, high pressure moves in
from the west. This will bring temperatures closer to average near
the coast, and about 5 degrees below normal for inland areas.
Another low pressure system far off the coast may influence the
weather later next week.

&&

.AVIATION...
282330Z...SCT-BKN marine layer clouds based 2500-3000 ft MSL are
currently developing over coastal areas. These clouds will likely be
transient with a period of clearing before areas of lower marine
layer clouds based near 2000 ft MSL begin to develop 04-08z Thu.
Coverage should become more uniform near the coast overnight with
patchier coverage spreading into inland valleys. Low clouds scatter
back to the coast 15-18z, though SCT low clouds may hang over
coastal areas all day, especially in San Diego County. Low clouds
based 2500-3000 ft MSL rush back inland early Thursday evening.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday. A
storm system arriving Saturday night and Sunday could generate
hazardous wind and sea conditions.

&&

.BEACHES...
High tides during the late mornings will generate significant
coastal flooding this week. Tides will be anywhere from 1.4 to 1.6
feet above astronomical predictions, bringing high tides to near 7.7
feet for Thursday morning`s high tide. A Coastal Flood Warning
remains in effect through Thursday afternoon and contains more
details.

While tides will continue to fall each day, a slight uptick in a
southwesterly swell on Friday (3 ft at 15-16 seconds) will bring
surf to 3-5 feet with sets to 6 feet. With the uptick in surf and
high tides near 7.25 ft at noon on Friday, a Coastal Flood Advisory
will replace the Coastal Flood Warning at 1 PM Thursday, in effect
until 2 PM Friday.


Additionally, storm system is set to bring increased surf on Sunday.
Stay tuned over the next few days for updates on expected surf as
details become more clear.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Warning until 1 PM PDT Thursday for Orange County
     Coastal Areas-San Diego County Coastal Areas.

     Coastal Flood Advisory from 1 PM Thursday to 2 PM PDT Friday for
     Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE/BEACHES...KW

NWS San Diego (SGX) Office