950
FXUS66 KSGX 051158
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
458 AM PDT Sat Sep 5 2026

.SYNOPSIS...
Patchy marine layer low clouds and fog can be expected this morning
as mid to high level clouds from Hurricane Marie begin to move
over the area by later today. Due to this, periods of light to
locally moderate precipitation later this evening through Sunday.
There is a slight (10-15%) chance of thunderstorms, mainly over
the San Bernardino Mountains and High Desert on Sunday afternoon.
Warmer and drier conditions Monday and Tuesday. Slight chance of
mountain showers and thunderstorms return for mid-week.

&&

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


...UPDATED AVIATION DISCUSSION...

Today through tomorrow night...

Latest GOES night fog reveals that there is very little in the way
of any marine layer present over the inner waters, with mostly just
patchy areas of low clouds along portions of the coastal areas of
San Diego County. There are also some passing mid to high level
clouds funneling up from the transverse banding associated with
Hurricane Marie, which is located roughly around 800 miles to the
south-southwest of the region. This will continue to track towards
the northwest and some of the moisture will become advected up ahead
of a longwave trough upstream and with some forcing, will result in
some developing bands of precipitation, which given where the best
convergence aloft is located, has the best chance over Riverside and
San Bernardino Mountains, tapering to lesser amounts to the south of
San Diego County. Given the timing and position of where these bands
of light to moderate rain establish themselves in a southwest to
northeast orientation, the better chance of rain looks to be during
the morning hours of Sunday with the highest PWAT values overhead.
Total rainfall amounts may reach over a half an inch over the San
Bernardino Mountains, and generally 0.20 to 0.30 inches within
the IE, with slightly lesser amounts to the coastal areas of
Orange County, and drastically tapering off to lesser amounts over
San Diego County (with possibly some areas over southern San
Diego County receiving little to no precip). These bands of rain
will eventually dissipate by later in the evening on Sunday.
Temperatures will remain on the cooler side, around and slightly
below the seasonal average for this time of year, and especially
for tomorrow as extensive cloud cover increases over the region.

Monday through Friday...

Drier conditions will return by Monday, with most of the moisture
associated with Hurricane Marie exiting the region, and only some
lingering moisture being advected up some the south which may allow
for a slight chance of a afternoon shower or storm to develop over
the mountains. As the ridge continues to build into the middle of
the week, with will warm temperatures back above the seasonal
average, with the warmest day peaking on Wednesday, which will find
high temperatures returning back into the low to mid 90s for the
inland areas. There will still be moisture in place that will move
up clockwise around the high pressure centered over the Four Corners
area that will keep a slight chance of afternoon showers and
thunderstorms for the mountains and adjacent deserts, along with a
gradual cooldown throughout the rest of the work week. The marine
layer will likely also continue to be displaced and patchy
throughout this next week.

&&

.AVIATION...
051200Z...Coast/Valleys...Some patchy low clouds with cigs will
remain very patchy coverage around 2,000ft MSL through this morning.
Low clouds are not expected to push very far inland with any Cigs
that may develop to be SCT or briefly BKN. Any low clouds will clear
out 10-13z. SCT-BKN mid-level clouds at 8-10kft move into the region
after 18Z along with a slight chance for -SHRA in San Diego County.
Low clouds will be even more patchy for tonight into tomorrow
morning, with increasing clouds and cigs lowering to around 6000-
8000 ft MSL, with a slight chance of -SHRA after 12Z, and increasing
chances thereafter throughout the rest of the forecast period.

Mountains/Deserts...VFR conditions prevail through the period.
Breezy westerly winds mainly through mountain passes and along
desert slopes. Gusts 25-35 kts with pockets of moderate
up/downdrafts over and in lee of ridges. Winds taper off slightly
after 09Z. Mid-level clouds 8-10kft will increase after 18Z,
bringing slight chance for -SHRA late evening, mainly in San Diego
County initially, then Riverside and San Bernardino counties with
higher chances of precipitation towards the end of the forecast
period.

&&

.MARINE...
No hazardous marine conditions are expected through Wednesday.

&&

.BEACHES...
A large south swell from Hurricane Marie will move into the region
tonight and Saturday, peaking Sunday into Monday, before gradually
diminishing Tuesday. This will result in elevated to high surf and
strong rip and longshore currents at majority of beaches.
Additionally, waves will occasionally run much farther up the beach
than expected, especially during increasing and high tides.

For south and southwest-facing beaches, expecting high surf 6-10
feet. This includes Orange County and north San Diego County
beaches. For west-facing beaches, expecting elevated surf 4-7 feet.
This includes most of southern San Diego County beaches.

High surf combined with high astronomical tides 6 to about 6.8 feet
will lead to tidal overflow and coastal flooding Saturday through
Tuesday during evening high tides, especially for those south and
southwest-facing beaches as well as low-lying, typically impacted
areas.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 11 PM PDT Tuesday for Orange County
     Coastal Areas-San Diego County Coastal Areas.

     High Surf Advisory until 11 PM PDT Tuesday for Orange County
     Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...Stewey
AVIATION/MARINE/BEACHES...Stewey

NWS San Diego (SGX) Office