Dana Point, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

535
FXUS66 KSGX 120401
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
901 PM PDT Mon Aug 11 2025

.SYNOPSIS...
Hot inland through Tuesday with high temperatures around 5-8
degrees above normal in the mountains and deserts. Gradual cooling
Wednesday through next weekend. Night and morning low clouds will
continue along the coastal areas and far western valleys,
spreading slightly further inland later in the week as the marine
layer deepens.

&&

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

High temperatures today were generally a few degrees lower than
yesterday at low elevations west of the mtns. In the deserts,
temperatures were about what they were. A few cumulus clouds
developed over the mtns this afternoon but relatively stable
conditions and a decrease in moisture didn`t allow for any storms
to develop. Dew point temperatures in the low deserts are lower
than at this time yesterday but there was no Mesoscale Convective
System (MCS) over Sonora MX last night. There is a MCS tonight so
we`ll see what effect, if any it has on the dew points in the low
deserts tomorrow. The marine layer is noticeably lower than
yesterday and low clouds are hugging the coastline. The sfc
pressure gradients are trending stronger onshore but it`s doubtful
that low clouds and fog will spread very far inland tonight.

From previous discussion...
High pressure continues to dominate the region. Most of the
monsoonal moisture will remain confined to the east. Looking at
high res models, such as the HRRR, they do pick up on the
development of a coastal eddy which becomes quite pronounced. With
the development of this, it should help to not only increase
coverage with slight thickening of the marine layer, and also help
to mitigate the threat for patchy fog out over the coastal
waters. That being said, there could still be some areas of patchy
fog, although there was not enough confidence of this occurring
this evening. Temperatures will still be on the more mild side
for the overnight lows, and with little transition in the longwave
pattern, and the ridge remaining over the desert southwest with
little difference of elevated heights of around 592 dm at 500 mb,
high temperatures tomorrow will be quite similar to where they
will be today, with even more confinement of mid-level moisture to
the east and resulting in nearly a nil chance of afternoon
convection for the mountains and deserts for tomorrow.

Wednesday through next weekend...
Wednesday will begin the transition of a slight cooldown and
increase of afternoon westerly winds for the normal areas
vulnerable to strong and gusty diurnal winds, such as within the
Coachella Valley. This is due to the ridge weakening along with
the region become more influenced by a longwave trough upstream
over the E Pac waters, which will be slowly progressing towards
the region. This will allow temperatures to become up to 10
degrees below the seasonal average for this time of year for some
of the locations, especially within the Inland Empire, by this
weekend. Dry conditions will also continue as the trough keeps
drier southwesterly winds in the mid-levels over the region and
suppresses monsoonal moisture further east of the CWA. During this
period in the forecast. The marine layer will also slightly lift
and thicken, extending further inland in the upcoming nights.

&&

.AVIATION...
120330Z...Coasts/Valleys...Low clouds have been lingering offshore
and along the beaches for the last several hours but are struggling
to fill in completely and push ashore at this hour (0330z Tue).
Still expecting clouds to fill inland and bring CIGs to the coastal
TAF sites by 04-06z. Bases will generally be 700-1100 ft MSL,
locally down to 300-600 ft MSL, and VIS down to 2-4 SM near higher
coastal terrain. Low clouds will scatter back out by 15-17z Tuesday
morning. Clouds look to stick near the coasts into the afternoon and
some beaches may only see partial clearing Tuesday afternoon. With
this, clouds should push back ashore by 03-05z Wednesday.

Mountains/Deserts...Mostly clear and VFR conditions continue through
Tuesday evening. A few stray cumulus clouds at ~10000ft MSL
possible over mountain peaks Wednesday afternoon.

&&

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

&&

.BEACHES...
Long period (16-17 second) southwesterly (200-220 degree) swell will
bring elevated surf and a high rip current risk through Friday. Surf
of 3 to 5 feet with local sets 6 to 7 feet.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Warning until 8 PM PDT Tuesday for Coachella Valley-
     San Diego County Deserts-San Gorgonio Pass near Banning.

PZ...None.

&&

$$

PUBLIC...PG
AVIATION/MARINE/BEACHES...Munyan