San Diego Weather at Mission Trails, CA

081
FXUS66 KSGX 192022
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
122 PM PDT Sat Jul 19 2025

.SYNOPSIS...
Chances for mountain thunderstorms will occur this afternoon,
becoming more minor by Sunday. A troughing pattern will take over
into the end of the week, bringing temperatures near average at
the coast and below average for inland areas. The marine layer
will persist through this period, bringing low clouds and fog
west of the mountains each night and morning.

&&

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

The marine layer presence continues to hold clouds along the
beaches, though the inversion continues to weaken, which will help
partially clear the area later this afternoon. Cumulus clouds
continue to build over higher terrain but no shower activity has
been detected yet. These clouds may build enough to generate
showers and weak thunderstorms this afternoon as a weak low over
the area helps funnel in monsoonal moisture. The low will stay
rather stationary but weaken further into tomorrow. Models
indicate the atmosphere continuing to dry out though some hi-res
models try to develop more precipitation across the mountain areas
by Sunday afternoon. Instability also lessens, so have kept
chances for storms near 10 percent during this time. Other areas
will continue to see a nice weekend with highs near to slightly
below average.

By Monday, a deeper trough will move into the Pacific Northwest
and Northern California, which will help to bring in cooler and
drier flow aloft. This will aid in pushing monsoonal moisture out
of California and further into AZ/NM. Tranquil weather will be
the name of the game next week as models indicate the trough
sticking around for awhile. This will bring temperatures near
average at the coast while inland areas see temperatures 5 to 10
degrees below normal. Even highs will stay a few degrees below
normal for parts of the Coachella Valley with highs near 105
degrees. The pattern will bring onshore winds to the mountains
each day with gusts 20-30 across the deserts, locally near 40 mph
in the passes. The marine layer will bring a daily dose of low
clouds and fog each morning west of the mountains with clearer
skies in the afternoons. Ensemble models begin to diverge on
solutions for next weekend, with some continuing the troughing
pattern while others provide a warmer solution with a weak ridge
forming over the Southwest.

&&

.AVIATION...
192030Z....Coast/Valleys...Only partial or intermittent clearing is
expected at the immediate coast this afternoon with low clouds based
at around 1500 feet MSL. These will push inland after 00Z, moving
into parts of inland valleys tonight. Tops around 2400 feet MSL and
local vis 2-5SM over higher inland terrain where clouds reach.
Scatter out Sunday will be around 17-20Z.

Mountains/Deserts...ISO TSRA (15-20% probability) through 01Z over
mountains, with CU/CB bases 8000-10000 feet MSL, tops to 35000 feet.
Erratic wind gusts, strong up/downdrafts, and VIS restrictions
possible with any TSRA. Skies clearing after 00Z. Cumulus buildups
Sunday 19-23Z based around 9000 feet MSL, but no TSRA expected.

&&

.MARINE...
No hazardous marine weather expected through Thursday.

&&

.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...APR
AVIATION/MARINE...MM