722
FXUS66 KSGX 020009
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
409 PM PST Sun Mar 1 2026

.SYNOPSIS...
High pressure aloft is weakening and shifting east and onshore
flow has returned. Temperatures will moderate near the coast as
marine air spreads inland but record-setting heat will continue
for many inland areas today, including the low deserts. The
cooling trend will continue through Monday, but with daytime
temperatures remaining above seasonal averages. There will be
stronger and gusty west winds each afternoon and evening in the
mountains and deserts today and Monday. Gusts of 35 to 45 mph are
likely in the wind-prone areas. Dry and a little warmer for
Tuesday through Saturday.

&&

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

...New Aviation Discussion for the 00z TAF Package...

Mostly sunny with some high clouds this afternoon. Temperatures
are generally a few degrees lower than at this time yesterday but
some locations in the coastal areas are as much as 7-12 degrees
cooler. This is a result of the return of onshore flow and
maritime air. The onshore flow is already strong enough that
wind-favored locations in the mountains and deserts are reporting
westerly winds gusting 20-35 mph.

From previous discussion...
The axis of the upper level ridge has shifted to the east as a low
pressure system off the coast of northern CA moves toward the coast.
A weakening cold front is associated with this system and is
approaching Point Conception from the west. The band of frontal
clouds will likely move into SoCal over the next 24 hours but is
unlikely to bring any precipitation. This low pressure system will
move eastward into the Great Basin by Tuesday. It will bring more
significant cooling for Monday when daytime high temperatures
will be in the 60s and 70s west of the mtns, in the 70s in the
high deserts, the 50s in the mtns and in the upper 80s to about 90
in the low deserts. These values are still near seasonal averages
in the coastal areas but above seasonal averages elsewhere. The
onshore flow will continue to strengthen, peaking on Monday when
it will produce southwest to west winds gusting 35-45 mph in the
mountains and deserts before weakening on Tuesday. Patchy marine
layer low clouds and fog will likely return to the coastal areas
late tonight then again Monday and Tuesday nights.

Temperatures will rebound somewhat for Tuesday and Wednesday as
the low pressure trough moves into the Rockies and a weak
transient ridge of high pressure moves over the region. Daytime
high temps will again be 5 to 11 degrees above seasonal averages
with mostly sunny skies after the low clouds and fog dissipate.

Numerical models remain in good agreement into Thursday before
solutions diverge as we move into next weekend. Another low
pressure system will move inland to the north on Thursday bringing
slightly lower temperatures for Thu and Fri along with another
round of strong onshore flow on Thursday.

Forecast details become more uncertain after Thursday as the
deterministic models show a closed upper low forming near SoCal by
Saturday. These models disagree significantly on the location of
the closed upper low. While a slim majority of ensemble members
across model platforms agree (in general) with this solution, a
significant minority of ensemble members produce a solution where
the upper trough remains an open wave and continues to progress
eastward into the southern Rockies. The first solution has the
potential to produce precipitation for SoCal while the second
solution keeps us dry. For now, the forecast remain dry but stay
tuned.

&&

.AVIATION...
020015Z....Coast...VFR conditions and mostly clear skies prevail
this evening before patchy marine layer clouds and FG return after
09z Mon. Brief and intermittent CIGs and IFR conditions possible
after 10z and through 16z at KSAN (30% chance) and KCRQ (25% chance)
with lower confidence for KSNA (10-15% chance). Bases of 300-700ft
MSL and VIS below 4SM at times, however, confidence is decreasing
for meaningful impacts overnight at coastal TAF sites. Any clouds
that did manage to move inland will push out after 16-18z Mon with
VFR prevailing thereafter.

Elsewhere...VFR with SKC-FEW250. Gusty winds in the mountains and
deserts with gusts up to 20-35 knots with locally higher gusts in
the mountain passes through this evening before a slight lull
overnight. Winds increase again to similar speeds after 16z Mon to
06z Tue. Mod up/downdrafts near mountain peaks and areas of BLDU
with reduced VIS in the deserts on Monday.

&&

.MARINE...
Northwest winds are increasing in the outer coastal waters, creating
hazardous conditions for small craft. Intermittent gusts of 20 to 25
kt expected, with seas of 4 to 7 ft. Strongest winds and highest
seas near San Clemente island. Winds and seas decrease Monday night
into early Tuesday.

&&

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


&&

$$

PUBLIC...PG
AVIATION/MARINE...Zuber

NWS San Diego (SGX) Office