Trabuco, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

931
FXUS66 KSGX 290439
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
Issued by National Weather Service Los Angeles/Oxnard CA
939 PM PDT Wed May 28 2025

.SYNOPSIS...
Seasonal temperatures will continue today, with low clouds
covering the region west of the mountains this morning. High
pressure aloft over California will bring warming for Thursday and
Friday, with Friday high temperatures as much as 10 to 15 degrees
above average for the Inland Empire. An upper level low pressure
system off the Baja coast could draw some tropical moisture
northward and into the area for the weekend with a chance of
showers. There will be a cooling trend for Saturday through
Tuesday with Tuesday high temperatures as much as 10 to 15 degrees
below average for the mountains.

&&

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

Update: Models still appear to be in relatively good agreement
with the upper level low slowly meandering to the south over the
Pacific Ocean Waters, southwest of the region. This is becoming
better resolved now, which shows that there will be a chance of
precipitation by later this weekend, especially for the mountains
on Sunday. Given that there will be somewhat of moisture feed
from a tropical system well to the south of Baja California, and
southeasterly flow at the mid levels, there could be enough
instability for the development of a few heavier showers and
possibly even a thunderstorm or two. This could allow for a few
locations to receive more significant amounts of
precip...otherwise most areas will likely only end up with a less
than a tenth of an inch of rain. This will be depended on how up
moisture is tapped into the U/L low from the subtropical system
(since the U/L low is relatively dry at the moment).

(Previous discussion submitted at 918 AM):

This morning, low clouds cover all of the low-elevation area west
of the mtns. The morning sounding shows the marine layer with a
similar depth to yesterday but with a stronger inversion. This
will likely result in slower clearing than yesterday, with some
low clouds lingering at the coast into the afternoon.

Through Friday...Daytime high temperatures will remain near
seasonal averages today, with night and morning low clouds
covering much of the region west of the mtns. High pressure aloft
over California will bring warming for Thursday and Friday. Friday
will likely be the warmest day with high temperatures as much as
10 to 15 degrees above average for the Inland Empire. High
temperatures on Friday will range from the lower 70s near the
coast to the 90s to around 100 for the Inland Empire, with 102 to
108 for the lower deserts.

A closed upper level low pressure system off the coast of northern
and central Baja could draw some tropical moisture into the area
from the south during the weekend, bringing us a chance of
showers. Numerical models are converging on a consensus solution
with respect to the timing and track of the upper level low so
forecast confidence is improving. For Sat through Sun, there is
about a 60 percent chance of measurable (0.01 inch) precipitation
in the San Diego County mountains and about a 45 percent chance in
other areas. There is is about a 40 percent chance of 0.10 inch
in the San Diego County mtns and a 20-30 percent chance elsewhere.

There will also be a cooling trend for Saturday through
Tuesday with Tuesday high temperatures as much as 10 to 15 degrees
below average for the mountains. High temperatures on Tuesday
will range from the lower to mid 60s near the coast to the upper
60s to mid 70s for the Inland Empire to the upper 80s and lower
90s for the lower deserts.


&&

.AVIATION...
290330Z...Coasts/Valleys...Low clouds based 1200-2000 ft MSL have
already pushed well into San Diego and Orange Counties. Expecting
the entire coastal basin to fill in overnight with FG along
coastal slopes of the mtns up to 4000 ft MSL. Patchy -DZ possible,
mainly in San Diego County. Low clouds will scatter to the coast
by 18-20z Thursday, but may remain BKN for the beaches and
nearshore waters through the afternoon. Low clouds based 1500-2200
ft MSL return for coastal areas after 03z Friday, but an
atypical flow pattern will keep clouds from pushing further
inland, thereafter.

Otherwise...mostly clear skies and VFR conditions through Thursday.

&&

.MARINE....
No hazardous marine conditions are expected tonight 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.

&&

$$

UPDATE...Stewey
PUBLIC...PG
AVIATION/MARINE...KW