Ranchita, California Weather Forecast Discussion

002
FXUS66 KSGX 090940
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
240 AM PDT Tue Sep 9 2025
.SYNOPSIS...
A large low pressure system moving slowly into the western states
will bring stronger onshore flow, spreading cooling inland and
deepening the marine layer to around 3000 feet with night and
morning coastal low clouds covering most of the coast and valleys
for early Wednesday and early Thursday. Southwest winds during the
afternoon and evening will gust to 30 to 40 mph for the deserts
onto the desert slopes of the mountains. This will be followed by
warming for Friday and Saturday and additional warming for early
next week with the marine layer becoming shallower.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Today through Thursday)...
A large low pressure system moving slowly into the western states
will bring stronger onshore flow, spreading cooling inland and
deepening the marine layer to around 3000 feet with night and
morning coastal low clouds covering most of the coast and valleys
for early Wednesday and early Thursday.
With the cooling, high temperatures for Wednesday and Thursday,
high temperatures will be 10 to 15 degrees below average for the
mountains, inland valleys, and high desert, and as much as 15 to
20 degrees below average for the higher elevations of the
mountains. High temperatures for Wednesday and Thursday will range
from the lower 70s near the coast to the mid 70s to lower 80s for
the Inland Empire with the lower to mid 90s for the lower
deserts.
There will be stronger and gusty southwest to west winds during
the afternoon and evening for the deserts onto the desert slopes
of the mountains with gusts to 30 to 40 mph. There will be
stronger gusts in the northern Coachella Valley below the San
Gorgonio Pass to 50 to 60 mph with the strongest winds today.
&&
.LONG TERM (Friday through Monday)...
There will be warming for Friday and Saturday with high
temperatures ranging from a few degrees below average near the
coat to 5 to 10 degrees below average for the mountains and inland
valleys. High temperatures on Saturday will range from the lower
70s near the coast to the 80s for the Inland Empire with the mid
to upper 90s for the lower deserts. The warming may plateau for
Sunday and Monday followed by additional warming into the middle
of next week.
The marine layer will become shallower with night and morning
coastal low clouds not spreading inland much past the far inland
valleys for the weekend.
&&
.AVIATION...
090930Z...Coast/Valleys...Low clouds based 900-1400 feet MSL will
become widespread along the coast and head into western valleys by
sunrise. Areas of reduced vis along inland extent of clouds 0-5SM.
Scatter out and improved vis 17-19Z. Low clouds to redevelop after
23Z and form inland overnight, filling the coastal basin early
Wednesday. Higher bases at 1500-2000 feet MSL and reduced vis far
inland valleys and hills.
Mountains/Deserts...Westerly winds will increase after 21Z with
areas of gusts 35-45 mph ridgetops and desert slopes, locally up to
60 mph in mountain passes through about 11Z Wednesday. Mostly clear
and VFR conditions today and tonight.
&&
.MARINE...
Occasional northwest wind gusts exceeding 20 kt in vicinity of San
Clemente Island in the afternoons and evenings through Wednesday
night. Otherwise, no hazardous marine conditions are expected
through Saturday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from 2 PM this afternoon to 1 AM PDT Wednesday for
     Apple and Lucerne Valleys-Riverside County Mountains-San
     Bernardino County Mountains-San Diego County Deserts-San
     Diego County Mountains-San Gorgonio Pass near Banning.
PZ...None.
&&
$$
PUBLIC...17
AVIATION/MARINE...MM

NWS SGX Office Area Forecast Discussion