Costa Mesa, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

611
FXUS66 KSGX 230500
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
900 PM PST Sun Feb 22 2026

.SYNOPSIS...
Dry and warmer through the end of the week, with high temperatures
rising to as much as 10 to 20 degrees above seasonal averages.
High clouds and weak offshore flow will continue through Tuesday,
then weak onshore flow returns with increasing chances for a
return of marine layer low clouds later in the week.

&&

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

Evening update...
A few thin high clouds were moving over the region this evening.
Surface pressure gradients are trending slightly stronger
offshore, currently around -8 mb SAN-TPH and -2.7 mb SAN-DAG. This
should be enough to keep any stratus that develops out to sea,
where the HREF has a 10-20% of low clouds. Chances at the coast
are less than 10%. Main change to the forecast this evening is
that winds are looking stronger for Wednesday as onshore gradients
increase and a weak trough passes by to the north.

Previous discussion...
Numerical models remain in good agreement through Friday with
respect to the evolution of the synoptic pattern. A ridge of high
pressure aloft will dominate the weather over SoCal and daytime
temperatures will steadily rise. High temps today will generally
be above seasonal averages and range from a few degrees above
seasonal averages in the mtns and deserts to as much as 12 degrees
above seasonal averages in the inland valleys. Friday will likely
be the warmest day with daytime high temps reaching the low to mid
80s in the inland valleys and the low 90s in the lower deserts.
These numbers are as much as 16 degrees above seasonal averages
in the valleys and up to 17 degrees above seasonal averages in the
lower deserts.

Weak offshore flow will persist into Tuesday and high-resolution
models indicate that marine layer low clouds/fog are unlikely to
return before Wed. The return of onshore flow will increase the
chances for a return of coastal low clouds/fog for Wed through
the end of the work-week.

Model solutions diverge as we move into next weekend so forecast
confidence is quite low for that time-frame. A significant number
of ensemble members show a low pressure system moving in from the
northwest. This could bring cooler conditions with increasing
clouds. The potential for precipitation is there but at this time,
only a very small number of ensemble members are indicating precip.

&&

.AVIATION...
230400Z...VFR with FEW-SCT cirrus AOA 25,000 ft through the TAF
period.

&&

.MARINE...
No marine hazards are expected 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...None.

&&

$$

PUBLIC...SS/PG
AVIATION/MARINE...KW