Crest California Weather Forecast Discussion

486
FXUS66 KSGX 112117
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
217 PM PDT Sat Oct 11 2025
.SYNOPSIS...
Cooler with drying and a return of the marine layer through the
weekend. A low pressure system moving southward along the West
Coast will bring stronger westerly winds from Monday onward along
with a chance of showers from the coast to the mountains Tuesday
into early Wednesday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Drier air from the northwest has filtered into the region with
sunny skies prevailing aside from a few low clouds still
scattering out of the deserts. Breezy conditions in the mountains
and deserts this afternoon and evening as a trough axis passes
well to the north. Otherwise, seasonable temperatures and low
marine layer clouds rebuilding into coasts and valleys through the
weekend with patchy fog for elevated valleys.
Starting Monday afternoon, an incoming shortwave trough will
begin to make its presence known in the mountains and deserts as
winds become elevated to locally strong along deserts and desert
slopes. Winds expected to peak Tuesday as the trough passes by
with lingering elevated winds into Wednesday. This system will
also be accompanied by much cooler temperatures and light
precipitation from the coasts to the mountains. As much as 15-20
degrees below average for inland areas. On that note, a dusting
of snow will be possible above 7500 feet. There is still
uncertainty in rainfall totals, but the track of the low almost
directly south from Canada should prevent any significant
precipitation totals. Generally expecting the highest amounts for
the valleys and mountains north of San Diego County, especially in
the western San Bernardino County Mountains where over an inch is
forecast. The lower deserts should remain totally rain-shadowed.
More seasonable and benign weather returns towards the end of
next week as an upper ridge expands into the area. This should
allow for the return of nighttime low marine layer clouds for
coasts and valleys as the inversion strengthens. Temps will remain
slightly below average even as high pressure builds.
&&
.AVIATION...
112040Z....Coasts/Valleys...Patchy low clouds 1400-1800 ft MSL
reform after 03Z Sun. Higher confidence (50-60%) of cigs impacting
coastal sites. Highest chances will be VCTY KSAN. Clouds scattering
back out 15-17Z Sunday.
Mountains/Deserts...Mostly clear through the weekend with VFR
conditions. Breezy west winds gusting 20-30 kts along desert
foothills, high desert, and typically windy spots in low desert
until 06Z tonight. Calmer winds expected on Sunday.
&&
.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
AVIATION/MARINE...APR

NWS SGX Office Area Forecast Discussion