831
FXUS66 KSGX 111600
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
900 AM PDT Sat Oct 11 2025

.SYNOPSIS...
Cooler with drying and a return of the marine layer for the next
two days. For Tuesday and Wednesday of next week, a low pressure
system moving southward along the West Coast will bring a chance
of showers from the coast to the mountains, along with stronger
westerly winds.

&&

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

Morning update...

Satellite imagery shows some low cloud development this morning
across the High Desert and Coachella Valley, but showers and high
clouds associated with the remnants of Priscilla have completely
exited the region. Otherwise, patchy low clouds over the waters
this morning indicate the beginnings of the redeveloping marine
layer. Looking towards next week, the forecast is still on track
with precipitation chances for all areas except the lower deserts
on Tuesday and Wednesday.

Previous discussion from 250 AM Sat...

This morning...Drier air from the northwest will bring fair and
locally breezy conditions to SoCal for this afternoon through
Monday as the low over WA/OR moves inland becoming an open wave
over the Rockies by Sunday. The westerly winds will be strongest
this afternoon, with the wind-prone locations of the mtns and
deserts likely to see wind gusts of 35-40 mph.

Fair and mild conditions will prevail through Monday as broad low
pressure troughing covers the western US, although temperatures
will remain several degrees below seasonal averages. The marine
layer low clouds and fog will return to the coastal areas and
valleys during the nights and mornings.

A reinforcing shortwave trough moving south out of western Canada
on the upstream side of the mean trough will form a closed upper
low over the WA coast by Sunday night. Numerical model solutions
are coming into better agreement through Wed and project the
upper low to move into central CA late Tue before moving eastward
into NV/UT by Wed. This system will bring colder air from the
north along with stronger westerly winds and chances for precipitation
Tue-Wed. Showers could move in from the northwest as early as Tue
morning and continue into Wed morning. Forecast details are still
somewhat uncertain but current rainfall estimates are for a few
hundredths of an inch over San Diego County to nearly an inch over
the western portions of the San Bernardino Mountains. The lower
deserts are likely to be rain-shadowed which is common for early
season systems moving in from the northwest with limited moisture,
most of which will have been rained out before the system reaches
SoCal. A dusting of snow is possible in wilderness areas of the
San Bernardino Mountains above resort levels. Showers should end
by mid-day Wed as the system moves inland. Tue and Wed will likely
be the coolest days with daytime temperatures as much as 15-20
degrees below normal for inland areas. The low deserts could be up
to 10 degrees below normal. Winds will peak Mon night/Tue morning,
with the wind-prone locations of the mtns and deserts potentially
seeing wind gusts of 50-55 mph.

Fair and gradually warmer towards the end of next week as the
system moves off to the east and high pressure expands eastward
over the west coast. Saturday will likely be the warmest day with
daytime temps still as much as 5-9 degrees below normal in the
inland valleys. The marine layer could return with low clouds and
fog for the coastal areas and valleys during the nights and
mornings.

&&

.AVIATION...
111530Z....Coasts/Valleys...Low clouds near 800-1000 ft MSL along
the San Diego County coastline will continue to diminish through
the morning. Patchy low clouds 1400-1800 ft MSL reform after 03Z
Sun, with low to moderate chances of impacting coastal sites (20-40%
chance). Highest chances will be VCTY KSAN.

Mountains/Deserts...Low clouds across the Coachella Valley and high
desert have now become VFR with bases near 3500-5000 ft MSL.
Expect these clouds to begin to scatter later this morning. Other
areas will see VFR mostly clear skies through the weekend. Breezy
west winds gusting 20-30 kts along desert foothills, high desert,
and typically windy spots in low desert 18-05Z.

&&

.MARINE...
Moderate northwest winds in the outer coastal waters will lead to
wind gusts occasionally exceeding 20 knots around San Clemente
Island this afternoon and evening. No hazardous marine conditions
are expected through Monday. Increasing south to southwest winds
expected by Tuesday as another weather system approaches the area.

&&

.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...KW/PG
AVIATION/MARINE...APR