San Diego Weather at Mission Trails, CA

000
FXUS66 KSGX 151614
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
914 AM PDT Mon Jul 15 2019

.SYNOPSIS...
Hot weather for inland areas will continue today. For Tuesday
through the end of the week, a trough of low pressure over the
West will bring cooler weather with a deeper marine layer. Clouds
will eventually extend farther into the valleys for Wednesday
into the weekend. For the weekend through early next week, high
pressure over the southwest states will strengthen. This will
bring a warming trend with the marine layer becoming shallower.
Some monsoonal moisture could return.

&&

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

High pressure aloft will begin to weaken today and Tuesday,
providing one more day of inland heat. Temperatures are expected
to be almost exactly as those yesterday overall. Low clouds and
fog along the coast this morning were part of a shallow marine
layer. The cloud on the higher coastal terrain and in westernmost
valleys was in contact with the ground, producing dense fog in
some areas. The larger cloud deck over the ocean eroded along much
of California`s coast yesterday and overnight, with some spinning
eddies beautifully observed in the Santa Barbara Channel and
around San Nicolas Island. There seems to be some erosive agent
behind the massive clearing up north, probably some north offshore
flow. All models show this clearing to continue today, dissolving
the cloud deck to almost nothing by this evening. A strong marine
inversion will preclude clearing at the beaches as with the past
few days, but the overall clearing of the cloud deck will probably
occur from west to east late today. It`s a little peculiar with a
coastal eddy brewing, but the clearing is already happening so
confidence is high in the guidance that suggests that will
continue. The forecast is for less cloud coverage later today
through Tuesday. A weak coastal eddy tonight will strengthen
Tuesday night into Wednesday, which should rebuild the stratus
cloud deck and provide more widespread and uniform coastal cloud
coverage Wednesday and beyond. The weakening high pressure aloft
will bring a very modest cooling trend Tuesday and Wednesday.
However, the coast will be warmer with fewer coastal clouds. A
stagnant summer pattern will continue this entire week with a
trough over the northwest coast and a ridge to the east over the
four corners. Dry southwest flow aloft will keep the monsoon
thunderstorm issue well to our east. The marine layer and its
cloud deck should rebound enough that coastal clouds and fog
should get into parts of the valleys during the nights and
mornings Wednesday and beyond. Daytime temperatures will dip below
average Wednesday as well, and continue that way into the
weekend. Next week the ridge to the east seems to build
northwestward, which would produce a modest warming trend, back to
normal or a little above. The ridge axis would migrate north,
allowing southeast monsoon flow into SoCal. That increasing
moisture would lead to a growing chance of thunderstorms for
mountains and deserts at some point next week.

&&

.AVIATION...
151600Z...Coast...Low clouds with bases 600-800 ft MSL will continue
to clear through 18Z with most vis now 3 miles or greater.  Most
locations will be clear with unrestricted vis this afternoon and
early evening. Stratus will be more patchy tonight but bases will
likely be low, 400-700 ft MSL with tops to 800 ft MSL. Local vis
below 1 mile is possible in fog 07Z-16Z Tue. Confidence is rather
low with timing and location of stratus/fog tonight.

Valleys/Mountains/Deserts...Mostly clear with unrestricted vis
through Tue.

&&

.MARINE...
No hazardous marine weather expected through Friday.

&&

.BEACHES...
The south swell of 3 feet 16 seconds will bring local surf to 6 feet
on south-facing beaches of Orange County today, along with a high
rip current risk. The swell and surf will decrease some tonight and
Tuesday.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT this evening for San Bernardino and
     Riverside County Valleys-The Inland Empire.

     Excessive Heat Warning until 8 PM PDT this evening for Coachella
     Valley-San Diego County Deserts.

PZ...NONE.

&&

$$

PUBLIC...MM
AVIATION/MARINE/BEACHES...Maxwell