Tustin Foothills, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

037
FXUS66 KSGX 250411
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
911 PM PDT Tue Jun 24 2025

.SYNOPSIS...
A gradual warming trend will continue through the end of the
week. The marine layer will bring night and morning low clouds to
coastal areas through the rest of the week. The marine layer is
expected to become shallower, with less low cloud coverage in the
valleys by the end of the week.

&&

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

Update: Low clouds continue to fill in along the coast this evening
and the inland areas will likely begin to see clouds increase
shortly after 10 PM for Orange and San Diego counties, and within
portions of the IE after midnight. The marine layer will be a little
shallower than previous nights, and therefore might not extend as
far east into the inland valleys/IE tonight. Over the course of the
next couple of days, the marine layer should begin to thin out and
lower a bit as high pressure begins to build back in stronger as
more ridging moves in over the region. Models have remained
relatively consistent with the overall weak ridging remaining over
the southwest CONUS as troughing remains confined over the east PAC
waters through the early part of next week with a gradual warmup
through then.

(Previous discussion submitted at 126 PM):

Visible satellite at 1 PM, was showing low clouds had cleared the
coast and valleys, with areas of high clouds moving west to east
across the Inland Empire. Low clouds will start to spread east
towards land this evening, and are expected to reach into the
valleys overnight. The marine layer is expected to remain 2000 to
2500 ft deep through Wednesday while we remain under cyclonic flow
aloft as a trough moves across the West Coast.

Highs Wednesday will be 4 to 8 degrees warmer than today for the
mountains, deserts, and inland valleys. An additional few degrees of
warming are expected into Thursday. The warming trend will bring
temperatures back to right around average for Thursday.

An area of high pressure from south of the border will build near
the Four Corners region for the end of the week into the weekend.
This will result in a more noticeable warming for the deserts Friday
through Monday. Chances of the low deserts exceeding 110 degrees are
highest on Sunday and Monday at 60 to 80 percent. There are some
indications that the position of the high pressure would allow for a
moisture surge from the southeast into the low deserts over the
weekend or early next week. If that were to occur, that would keep
high temperature readings on the lower side of guidance. For Sunday
and Monday, there is a 7 degree difference between the warmest and
coolest solutions with the coolest solutions staying right around
105 degrees and the warmest exceeding 110 degrees.

Conditions are also expected to warm up west of the mountains, but
an upper level weak trough lingering off the coast of Southern
California is expected to keep the aforementioned high pressure from
moving too far west. Chances of the Inland Empire exceeding 100
degrees on Sunday and Monday are mostly 20 to 30 percent, locally up
to 50 percent in the eastern portion of the Inland Empire. For the
eastern San Diego valleys, chances for temperatures to exceed 90
degrees are 30 to 50 percent. Chances of inland Orange County
exceeding 90 degrees on Sunday and Monday are closer to 10 to 20
percent. The low is expected to be close enough to maintain marine
layer low clouds and fog along the coast but influence from the high
pressure aloft should keep the marine layer shallower and less
likely to reach the inland valleys.

&&

.AVIATION...
250300....Coast/Valleys...Low clouds based 1300-2000 ft MSL have
pushed into coastal SD/Orange Counties. Expecting remaining coastal
areas and inland valleys of SD/Orange to fill in over the next
several hours. Patchy clouds likely to reach into parts of the IE
again 10-12z Wed. 60% chance of BKN CIGs at KSBD. Minor vis
restrictions (3-5SM) for elevated inland areas including the IE.
Clearing to the coast 17Z-19Z Wed. Clouds with slightly lower bases
return to coastal areas after 03z Thu.

.Mountains/Deserts...Clear skies with unrestricted VIS through
Wednesday evening.

&&

.MARINE...
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...None.
PZ...None.

&&

$$

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