231
FXUS66 KSGX 021226
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
426 AM PST Mon Mar 2 2026

.SYNOPSIS...
An approaching trough will allow for notably cooler temperatures
today. There will be stronger and gusty west winds this afternoon
and evening in the mountains and deserts today. Gusts of 35 to 45
mph are likely in the wind-prone areas. Dry conditions will
likely continue throughout the rest of the week, but then there
could be a slight chance of precipitation by later this upcoming
weekend.

&&

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

Today through tomorrow night...

At 4 AM this morning, the GOES 18 Night Fog satellite imagery
reveals that the marine layer is still rather dispersed, and not yet
well formed up over the inner waters of the SoCal bight at this
time. There are only a couple of patchy areas of fog and low clouds
developing around La Jolla and Carlsbad at the moment. This will
likely continue to struggle to develop through this morning, with
weak offshore winds in place. There could be some patchy areas of
fog developing within some of the wind-sheltered valleys through the
early hours.

The ridge over the southwest region is continuing to break down and
weaken as an area of troughing upstream, with an associated area of
low pressure located over the E Pac waters west of northern
California, continues to propagate eastward and will eventually move
in over the Great Basin. This feature will begin to influence SoCal
and provide us with increasing surface winds, which will become
quite breezy by later in the afternoon across the higher elevations,
and especially through the mountain canyons and passes, where there
could be some gusts approaching 50 mph through the San Gorgonio pass
and Banning. There will also be increasing mid to high level clouds,
although the main energy will be far enough north that we are not
expecting any precipitation with this. These strong and gusty winds
will decouple by later this evening, and further diminish in
strength going into tomorrow. Much cooler temperatures will be
advected in behind this system, and therefore high temperatures for
this afternoon will be notably cooler from where they have been in
recent days, and much closer to the seasonal average for this time
of year.

The onshore flow is going to become predominant, which will help to
advect in lower level moisture, and therefore allow for there to be
better marine layer coverage for later this evening into early
tomorrow. These cloud bases will likely start out around roughly
1000 to 1500 ft, and then continue to gradually lift. There may
possibly be a few areas of patchy light drizzle along some of the
coastal slopes and the western-facing slopes of the inland foothills
during the late evening hours today, and through the early morning
hours tomorrow. There will be some weak upper level ridging moving
in behind the exiting trough, which will bring about a brief warmup
on Tuesday.

Wednesday through the upcoming weekend...

By Wednesday into Thursday, another trough is going to deepen and
skirt across just to the north again, which will help to strengthen
westerly winds again, and also reinforce some cooler temperatures.
Then after the passage if this trough and brief building in of high
pressure in its wake, there is going to be a deepening trough over
the inner mountain west which will begin to deepen sharply and
possibly become a cut-off upper level low just to south of the
region as some of the deterministic models suggest. However, there
is still such dispersion between these models that confidence is low
if this will actually provide us with any measurable precip, though
it is probably safe to say that there will be at least a slight
chance by later in the upcoming weekend.

&&

.AVIATION...
021000Z....Coast...Patchy low clouds and fog most likely between 13-
16Z. Any cigs that form will be around 500 feet MSL with vis 2-5SM,
but confidence is low for these impacts for any length of time.
Better confidence in areas of low clouds after 06Z tonight into
Tuesday. Cigs would be closer to 1500 feet MSL.

Otherwise...VFR with SCT high clouds. Areas of gusty southwest winds
25-35 knots in the mountains and deserts between 16-02Z. Mod
up/downdrafts in lee of ridges. Locally reduced vis in BLDU in
deserts.

&&

.MARINE...
Gusty northwest wind gusts exceeding 20 knots mainly around San
Clemente Island will generate locally choppy seas this afternoon and
evening. The Small Craft Advisory in effect contains the details. No
additional marine hazards are expected late tonight through Friday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PST this evening for Waters from
     San Mateo Point to the Mexican Border Extending 10 to 60 nm
     out including San Clemente Island.


&&

$$

PUBLIC...Stewey
AVIATION/MARINE...MM

NWS San Diego (SGX) Office