Costa Mesa, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

973
FXUS66 KSGX 070544
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
944 PM PST Fri Mar 6 2026

.SYNOPSIS...
Gusty Santa Ana winds will continue through the weekend across the
mountains into the inland valleys as an area of low pressure
nears the region. This will also bring warmer weather. The system
will move southward into Mexico, where there is a small chance
for light rain over San Diego County by late Sunday into Monday.
High pressure will move over the region for much of next week,
bringing warm and dry weather.

&&

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

Evening update...
Skies are clear this evening. Weak offshore flow is ongoing, but
surface pressure gradients are beginning to strengthen, currently
around -8.4 mb SAN-TPH. Water vapor imagery shows the positively
tilted upper level trough across the Desert Southwest. This low
will retrograde and deepen as it moves towards So Cal, with a vort
max forecast to move across our forecast area tonight. This will
cause northeast winds to strengthen, peaking late tonight into
late Saturday morning with gusts of 40-50 mph across the mountains,
valleys, and inland Orange County. Isolated gusts of 60-65 mph are
possible along the coastal slopes of the San Bernardino Mountains
and below the Cajon Pass and in the Santa Ana Mountains.

Previous discussion...
The area of low pressure will move further south on Saturday into
Sunday, which will favor a more easterly wind component around the
northern side of the system. These easterly winds will begin to lead
to stronger winds across San Diego County during this time period.
Highest winds will occur during the morning and afternoon hours each
day. Moderate to high chances exist for foothill regions to reach 40
MPH, while valleys see these chances closer to 25-30 MPH. Offshore
flow will also bring the greatest warming by Sunday. Western valleys
will see moderate to high chances (50-80%) in seeing highs reach 85
degrees. There is about a 50-60% chance to reach 90 degrees across
inland Orange County. These high temperatures would be 15-20 degrees
above normal for early March. The low will wrap around minimal
amounts of moisture with a slight increase in precipitable water
values, which may be able to provide light rain showers from the
deserts to the western valley regions in San Diego County by Sunday
night into Monday. Chances remain low near 15-25 percent with high
confidence in light amounts possible.

Ensemble models show good agreement on the movement of this system,
pushing it out of the area by Tuesday. High pressure off the coast
will move into the area for much of next week. Cooler weather
returns on Monday as offshore winds weaken, but a warming trend
continues through the week as high pressure off the Pacific
strengthens over our region.

&&

.AVIATION...
070600Z....Coast/Valleys...VFR through Saturday evening. N/NE gusts
increase to 20-30 kts after 09z, then increase more significantly
after 14z Sat morning to 35-50 kts through the Inland Empire (below
the Cajon Pass) and 25-40 kts throughout Orange County. Winds
decrease slightly after 21z (still elevated 20-35kts), then greater
confidence for more significant wind weakening after 02z Sun, though
periods of gusty winds are possible through Saturday evening.
Localized areas of LLWS and mod up/down drafts expected, especially
in the lee of mountains.

Moderate for gusts above 30 kts at KSNA, 15-20z. Moderate to high
confidence for gusts above 35 kts at KONT, 15-22z.

Weaker offshore winds (10-20kts) for the SD County coast after 12z;
onshore (NW) winds only reaching areas along the immediate coast,
after 18z Sat.

Mountains/Deserts...VFR with FEW-SCT high clouds AOA 20,000ft MSL
this evening. Periods of gusty N/NE winds expected through Saturday
evening: sustained at 20-35 kts, and gusts 25-45 kts with isolated
gusts to 55 kts through mountain passes and on coastal facing
foothills. Areas of LLWS and mod up/down drafts in lee (south of)
mountains mainly in SBD County. Peak gusts in SBD/OC/Riv Co. mtns 12-
20z Sat; peak gusts over SD Co. mtns not until after 00z Sun.

Low confidence on gusts exceeding 35 kts at KPSP Saturday, most
likely 12-16z.

&&

.MARINE...
Intermittent gusts near 20 knots possible in the outer coastal
waters near San Clemente Island early Saturday morning and again
Sunday evening. Otherwise, no additional hazardous marine conditions
are expected through Tuesday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 5 PM PST Sunday for Orange County Inland
     Areas-San Bernardino County Mountains-San Bernardino and
     Riverside County Valleys-The Inland Empire-Santa Ana
     Mountains and Foothills.

     Wind Advisory until 5 PM PST Sunday for Riverside County
     Mountains-San Diego County Mountains-San Diego County
     Valleys-San Gorgonio Pass near Banning.

PZ...None.

&&

$$

PUBLIC...SS
AVIATION/MARINE...Westerink