San Onofre, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

087
FXUS66 KSGX 222126
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
126 PM PST Sat Feb 22 2025

.SYNOPSIS...
A warming trend sets in for much of the week, with temperatures
reaching 10-20 degrees above normal by Wednesday when elevated
Santa Ana winds return. A pattern shift late in the week brings a
return of cooler weather and a chance of light precipitation into
the weekend.

&&

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

Warm weather and light winds prevail today and tomorrow as weak
upper level ridging moves in. The dense fog that was observed this
morning is expected once again Sunday morning with similar
coverage and extent, generally along the coast/beaches and up to
5-10 miles inland. Temperatures will slowly warm through
Monday/Tuesday with zonal flow aloft, providing afternoon highs
in the 70s along the coasts, 80s for the valleys and inland areas,
60s and 70s for the mountains, and 80s to 90s for the deserts.

A closed low over the PacNW will transition to an open trough and
sweep down to the Four Corners on Wednesday, with gusty offshore
winds developing across much of the region. Despite the weak to
moderate easterly flow, elevated fire weather conditions may exist
on Wednesday as relative humidity plummets to single digits
everywhere east of the valleys. This dry, warm flow will also cause
temperatures to soar as highs reach near 20 degrees above normal,
reaching the 90s for some desert areas. While temperatures peak
Wednesday, highs remain exceptionally warm into Thursday as the
trough slowly propagates southward through Arizona. Given these
unseasonably hot temperatures, those outside may be caught off
guard by the heat. Make sure to practice proper heat safety,
remaining hydrated and taking frequent breaks in the shade, and
avoid outdoor work during the hottest hours of the day.

The pattern changes substantially on Friday as the prevailing hot
and dry weather comes to an end. While there remains substantial
disagreement with the models later this week, some runs continue to
indicate a chance for some precipitation as a upper level low moves
into Southern California on Friday, followed closely by a secondary
trough set to come across late weekend. The signal remains fairly
weak for precipitation with this first low, chances slightly better
with the second, but there is still good agreement on the
substantially cooler weather expected to accompany this pattern
shift. Highs may fall drastically Friday compared to Thursday,
closer to near normal, with the cooler weather prevailing through
the weekend.


&&

.AVIATION...
212200Z...Coast/Inland Valleys...Clouds will redevelop and push back
ashore after 06z this evening into Sunday morning, with very similar
coverage, CIGs, and VIS as this morning. Some of these low
CIGs/FG/BR could extended into portions of the inland areas again,
especially within the Mission Valley, otherwise the majority of the
inland valleys will remain VFR for the most part. There could also
be localized areas of patchy fog out over the coastal waters,
otherwise bases will hover around 100-200 feet MSL. This will begin
to erode from east to west between 16-17Z tomorrow morning and
scatter out shortly thereafter along the coastal areas, with
intermittent BKN coverage possible around 500-1000 feet MSL along
the extreme coastal areas during the afternoon hours tomorrow.
Expect low clouds  and patchy fog, with bases of 100 to 500 feet
MSL, to return again by later in the evening tomorrow after 06Z
Monday, and continue to fill into some of the inland valleys through
Monday morning.

Valleys/Mountains/Deserts...Mostly clear skies with unrestricted VIS
will prevail through Sunday.

&&

.MARINE...
No hazardous marine conditions are expected through Wednesday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...Zuber
AVIATION/MARINE...Stewey