031
FXUS66 KSGX 050539
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1039 PM PDT Fri Sep 4 2026

.SYNOPSIS...
Patchy marine layer low clouds and fog can be expected overnight and
in the morning as high level clouds from Tropical Cyclone Marie move
over the area this weekend. Periods of light to locally moderate
precipitation are possible Saturday and 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...

Hurricane Marie remains on a track toward the west-northwest with
the center to remain well to the southwest of the area through the
holiday weekend. The current NHC forecast has Marie weakening to a
tropical storm on Sunday. The main impacts expected for Southern
California over the weekend are increased surf, coastal flooding,
and periods of light to locally moderate precipitation.

Mid to high level moisture from Marie will begin to increase from
the south tonight into Saturday, increasing chances of showers
for San Diego County. The moisture will continue to shift north
Saturday into Sunday, increasing precipitation chances for Orange,
Riverside, and San Bernardino Counties. For much of the area the
most likely peak rainfall rates will be 0.20-0.40 inches per hour.
There is a slight chance (10-15%) of thunderstorms over the San
Bernardino mountains and High Desert Sunday afternoon. Current
guidance indicates we`ll be on the edge of the bulk of the
instability. If the high cloud coverage is widespread enough to
limit heating from the sun any afternoon convection may be
thwarted.

For this weekend, high temperatures will remain below average inland
with highs near the coast running a few degrees above average.
Overnight lows will also return to above average for this time of
year by Sunday. By Wednesday, high temperatures will be within a few
degrees of average for the mountains and deserts and a few to around
5 degrees above average for the coast and valleys. Above average low
temperatures will be maintained into next weekend. High temperatures
will gradually cool into next Friday.

The upper level flow turns south/southeasterly Wednesday and
Thursday, which may allow for some additional moisture to creep into
the area. There remains some uncertainty in the upper level pattern
with the position of the upper level ridge over the southern US
and a trough off the US West Coast. A more easterly position of
the trough would result in drier conditions with a more westerly
position of the ridge allowing more moisture into the area.
Current forecast follows the NBM which has 20 to 35 percent chance
of precipitation over the mountains Wednesday and Thursday
afternoon and a slight chance of thunderstorms.

&&

.AVIATION...
050530Z...Coast/Valleys...Current;y there are some patchy low clouds
out over the local waters with a few wafting in across the Orange
County coast. Not expecting any significant impact with Cigs
overnight tonight with very patchy coverage around 2,000ft MSL. 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.


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 in the afternoon, mainly in San
Diego County.

&&

.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 from 6 AM Saturday to 11 PM PDT Tuesday
     for Orange County Coastal Areas-San Diego County Coastal
     Areas.

     High Surf Advisory from 6 AM Saturday to 11 PM PDT Tuesday for
     Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...CO
AVIATION/MARINE/BEACHES...Villafane

NWS San Diego (SGX) Office