Perris, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

896
FXUS66 KSGX 070431
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
930 PM PDT Sun Apr 6 2025

.SYNOPSIS...
Fair warm weather will prevail this week. Patchy low clouds and
locally dense fog should return to the immediate coast by Monday
morning and likely again Monday night and Tuesday morning. Inland
highs will be 10 to locally 20 degrees above normal Wednesday
through Friday. Cooler weather will return next weekend.

&&

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

Update...
SKies were mostly clear, though Low clouds and fog are over the
parts of the coastal waters near San Clemente and Catalina Islands.
There is around a 70 percent chance at least some low clouds/fog
will reach the coast by sunrise Monday, and the fog could be locally
dense due to the initial shallow marine layer. Farther northwest,
Oxnard currently has cloud ceilings of 300 feet which highlights the
shallow marine layer, and often the ceilings and visibilities go
down overnight in this pattern. Otherwise, the increasing heat
inland is still on track with Palm Springs having 2-3 days at/above
100 F Wed-Fri, but following by a cooling trend over the weekend,
though confidence is low on how rapid that trend will be.

From previous discussion...
For Monday and Tuesday...Inland temperatures contiWarm and fairnue
the upward
trend while the upper level ridge weakens in response a low
pressure trough moving inland to the north. The resulting onshore
flow and the return of the marine layer will moderate temperatures
in the coastal areas and western portions of the inland valleys.
Daytime temperatures will range from the upper 60s at the beaches to
the low 80s in the inland valleys. The upper deserts will be in
the upper 70s to lower 80s and the lower deserts will be in the
low to mid 90s.

For Wednesday through Friday...A large-amplitude ridge of high
pressure builds over the western states. This will bring
significantly warmer conditions and a reduction in the marine
layer presence, limiting the nocturnal low clouds and fog to the
immediate coastal areas. Thursday will likely be the warmest day,
with daytime high temperatures in the low 90s for portions of the
inland valleys and upper deserts. High temperatures in the lower
deserts will be near 100 degrees at some locations. The national
Blend of Models shows a 55-90 percent chance of 100 degrees or
more on Thursday in the lower deserts. It also shows a 70-90
percent chance of 90 degrees or higher in the IE and upper
deserts. Except for the lower deserts where temperatures could be
a little higher, Friday will not be quite as warm as the upper
level ridge begins to shift eastward and heights/thicknesses begin
to lower as a trough of low pressure approaches from the
northwest.

The trough will take control of SoCal weather for next weekend,
bringing stronger onshore flow with more clouds and lower
temperatures. By next Sunday, temperatures west of the mountains
will be back down to the 60s and 70s. In the high deserts,
temperatures will be back down to the 70s and in the lower deserts
the upper 80s to near 90. There is still significant uncertainty
in the forecast details for the weekend due to the spread in the
ensemble member solutions.

&&

.AVIATION...
070330Z...VFR and clear skies continue this evening though chances
for low clouds and fog look to increase after 09z Monday.
Current thinking is that these clouds, if they do arrive, would be
based near 300-500ft MSL and bring VIS down to 1-3 SM, locally less
than 1 SM along the higher coastal terrain. CIG/VIS restriction
chances peak between 12-16z. Any low clouds/BR/FG that do develop
will scatter out by 16-17z Monday, with full clearing by 18z. There
is a 40-60% chance of seeing CIG/VIS reductions described above at
KSAN and KSNA between 12z-16z, with a 30-40% chance for KCRQ.

&&

.MARINE...
Patchy fog could bring visibilities near 1SM tonight, clearing
Monday morning. No hazardous marine conditions are expected through
Friday.

&&

.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...Maxwell (Update)/PG (Previous Discussion)
AVIATION/MARINE...Munyan