Portola Hills, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

528
FXUS66 KSGX 091223
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
400 AM PST Sat Nov 9 2024

.SYNOPSIS...
Dry weather will continue through most of next week. A return to
weak onshore flow ahead of a Pacific weather system will bring
slight cooling Sunday and Monday with a return to coastal low clouds
and fog Sunday night. The Pacific weather system Monday night and
Tuesday will likely keep us dry. Weak offshore flow will bring
warmer weather again around the middle of next week before cooling
returns late next week with a chance of rain, mainly Friday night
and Saturday.

&&

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

Skies were clear with generally light winds and low humidity. That
is resulting in some rather chilly low-lying spots that are normally
prone to radiational cooling, including 37 at Oceanside Airport, 35
at Ramona Airport, and 28 along the Mojave River at Apple Valley at
4 AM, though higher elevations surrounding these stations are
considerably warmer, especially Mt. Woodson which at 63 is 28 deg F
warmer than Ramona Airport. After the morning warmup, we should be
mostly from near normal to 5 deg F above normal.

A weak ridge of high pressure will gradually move east from SoCal
today to Arizona Sunday as a shortwave gradually approaches from off
the coast. That shortwave will not have much impact as a closed low
will form at the southern edge and stay to our southwest until it
moves into the central part of the Baja peninsula Tuesday. With the
weak trough moving through Monday night/Tuesday, total precipitable
water only increases slightly (likely staying at/below 0.4"), and
without significant dynamics, it would be highly unlikely to get any
precip from this system, so it has been removed from the forecast
for Monday night. Regardless, there should be some cooling through
Monday as onshore flow brings some marine air, enough possibly for
stratus/fog near the coast during the nights/mornings.

After that low moves east, another weak ridge will move over at mid-
week and combine with weak offshore flow to bring warming. There is
a chance of rain Friday night/Saturday of next week due to a
potentially broader deeper trough, though timing is in question
given this is a week away with moderate amount of spread among the
ensemble solutions. More than half the ensemble solutions from
GEFS/EPS have measurable rain at some point between Friday and early
the following week, with generally light amounts.

&&

.AVIATION...
091100Z...VFR with mostly clear skies today and tonight. Light
winds, with weak offshore winds overnight and in the morning
followed by slightly stronger afternoon sea breezes.

&&

.MARINE...
Stronger northwest winds are expected late Monday afternoon through
early Tuesday morning ahead of a Pacific weather system, with gusts
around 20 kts in the outer coastal waters, strongest near San
Clemente Island. Otherwise, no hazardous marine conditions expected
through Tuesday.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory until 9 AM PST Saturday for Apple and Lucerne
     Valleys.

PZ...None.

&&

$$

PUBLIC...Maxwell
AVIATION/MARINE...CSP