469
FXUS66 KSGX 240436
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
936 PM PDT Thu Apr 23 2026

.SYNOPSIS...
Cooler and breezy weather will occur this weekend as a weak
weather system moves over the area. This system will bring gusty
winds across the mountains and deserts along with the chance for
some light precipitation along and west of the mountains as well.
Next week will remain cooler with highs near to slightly below
average and mainly dry weather.

&&

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

Evening update...
Skies are mostly clear this evening with just a few high clouds
moving overhead. Patchy low clouds are developing over the coastal
waters. The 00Z KNKX sounding shows the marine inversion remains
fairly weak, so expect low cloud coverage to be somewhat patchy
again tonight into Friday morning. We remain under mostly zonal
flow on Friday with temperatures within a degree or two of late-
April normals.

Previous discussion...
An upper level low will move over our region this weekend. As it
does so, the onshore pressure gradient will tighten, leading to an
increase in winds across the mountains and deserts. Widespread
westerly wind gusts of 25-45 MPH will be common across these areas
Friday afternoon and night.

As the system draws closer to the region on Saturday, the
pressure gradient will tighten further, leading to the highest
winds of the event. Models show mountain winds 45-55+ MPH with
desert winds 35-45 MPH, generating some blowing dust across the
deserts at times. Model consensus is fair in light showers moving
into the area as early as Saturday morning, mainly along the
coastal slopes. The weather system will move over the area
Saturday night into Sunday morning, giving way to the best chance
of showers from the mountains to the coast. Hourly rain rates will
mainly be near one tenth of an inch or less, with total
accumulations below one quarter of inch west of the mountains.
Snow levels will also drop near 6,500 feet, where there is high
confidence that totals will remain below one inch. Sunday will be
the coolest day of the week for many with highs 40s/50s across the
mountains, 60s in the highest desert and coastal basin, and
comfortable 70s in the lower deserts.

The troughing pattern will stick around for much of the week,
which will lead to lighter onshore winds and temperatures near to
slightly below average with dry weather. Models do hint at another
weak area of low pressure forming in our vicinity by later on
Tuesday or Wednesday, which may bring some increased wind and
chances for precipitation. The forecast details still remain in
flux as model timing and placement differences are present. After
this, forecast models have better agreement on a dry weather
pattern as we head into the month of May.


&&

.AVIATION...
240430Z...Coast/Valleys...Generally VFR conditions expected through
this evening. Low clouds will struggle to reform tonight. Best
chance for patchy BKN low clouds will be over coastal areas late (12-
16z Fri). 40-50% chance for intermittent BKN cigs based 1800-2400 ft
MSL at coastal TAF sites. Any low clouds scatter out by 18z with VFR
conditions for the afternoon. Low clouds based 2500-3000 ft MSL
return early Friday evening to coastal areas with much more uniform
coverage. Clouds quickly spread into most of the coastal basin late
Friday evening and overnight with bases rising above 3000 ft by
early Saturday morning.

Mountains/Deserts...Westerly winds strengthen after 00z Sat with
widespread gusts 25-35 kts, locally to 45 kts along desert slopes
and through mountain passes. Moderate up/downdrafts expected in lee
of mtns.

Otherwise...SCT-BKN high clouds expected through the period.

&&

.MARINE...
No hazardous marine conditions are expected through Tuesday, though
brisk westerly winds 15 to 20 kts are expected each afternoon
through Sunday.

&&

.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...SS/APR
AVIATION/MARINE...KW

NWS San Diego (SGX) Office