511
FXUS66 KSGX 081101
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
301 AM PST Sat Nov 8 2025

.SYNOPSIS...
Warmer conditions expected through early next week with a shallower
marine layer and periods of weak offshore flow. Warmest days are
expected to be Sunday and Monday. Offshore flow will be strongest
Sunday into Monday morning. Cooler conditions expected for the
middle to end of next week along with stronger onshore flow,
increasing clouds and chances for precipitation late Thursday into
Saturday.

&&

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

This morning, the marine layer is significantly shallower than
yesterday at about 1500 ft deep, mainly due to the building high
pressure ridge over the west coast. Low clouds have not spread as
far inland, with patches of dense fog on elevated coastal terrain.
Meanwhile, sfc pressure gradients continue to trend stronger
offshore with -7.0 mb SAN-TPH and -1.8 mb SAN-DAG. At this hour,
winds remain quite weak with northeast winds gusting locally to 20
mph.

The high pressure ridge will continue to build through Monday
before beginning to weaken and shift eastward on Wednesday in
response to intensifying low pressure system over the eastern
Pacific. As the ridge settles over CA on Monday, a closed upper
low forms about 1300 miles west of San Diego. The building high
pressure and offshore flow will continue to bring a warming trend
through Monday which is likely to be the warmest day. On Monday,
daytime high temperatures will reach the low 90s in the inland
valleys. This is about 15 degrees warmer than the seasonal
average. Offshore flow is expected to continue strengthening and
peak late Sunday into early Monday when we could see northeast to
east winds gusting locally to 40 mph in the mtn passes and on the
coastal foothills. The marine layer will become even shallower
with low clouds and fog confined to the immediate coastal areas.

By the middle of next week, a low pressure system from the Gulf of
Alaska will merge with the low pressure system to the west. The
now much larger low pressure system will begin to move onshore
along the west coast on Thursday. This will weaken and displace
the high pressure ridge to the east. As this system moves inland,
it will certainly bring cooler conditions, stronger onshore flow,
a deeper marine layer with increasing clouds and the potential
for precipitation for late Thursday into Saturday. Beyond
Wednesday, the forecast details are still quite uncertain due to
significant spread in model solutions, however about 60% of
ensemble members across model platforms now indicate precipitation
for Friday and Saturday. It`s still too early to estimate precip
amounts with any confidence but this system has the potential to
bring at least some rain to much of Souther California.

&&

.AVIATION...
080930Z...Coasts/Valleys...Low clouds based 600-900 ft MSL are
patchy, extending 5 to 15 miles inland. Widespread minor VIS
reductions; 3-5SM in coastal areas with BR/HZ. Greater VIS
reductions in FG; 1/4-1SM for elevated coastal areas, inland valleys
around I-15 and in parts of the western Inland Empire. VIS improves
15-17z. Low clouds scatter to the beaches 18-20Z but likely to
linger along the immediate coast through Saturday afternoon. Low
clouds 500-900 ft MSL move back ashore after 00Z Sun, spreading to
western inland valleys of SD county and into inland areas of Orange
county. Moderate confidence for similar VIS reductions after 05-07z
Sun.

Mountains/Deserts...Clear skies and VFR conditions through the
period.

&&

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

&&

.BEACHES...
Surf heights of 4 to 6 feet tonight will decrease to 3 to 5 feet
Saturday morning and will continue to gradually lower through the
weekend.

&&

.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...PG
AVIATION/MARINE/BEACHES...Westerink