628
FXUS66 KSGX 112041
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
141 PM PDT Sat May 11 2024

.SYNOPSIS...
Low clouds and fog expected each night and morning for the coast and
valleys through the next week. A few degrees of warming is expected
Sunday, with cooling Monday and Tuesday. A few light rain showers
may develop over the mountains Tuesday and Wednesday afternoons,
with minimal accumulations expected. There is some uncertainty in
the forecast for the latter half of next week, but temperatures for
inland locations look to stay near or a few degrees above average
for this time of year.

&&

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

Low clouds are sticking along the beaches as of 1 PM this afternoon,
with some low topped cumulus development along the mountains. Night
and morning low clouds and fog are expected to remain present each
day through next week. Some fluctuation on how far inland low clouds
push each night is expected, with a lesser inland extent for the
first half of the week and a deeper marine layer possible towards
the middle to end of next week.

Weak ridging is expected over Southern California Sunday. This will
allow for a brief warming trend, most noticeable for inland areas.
Highs in the lower deserts are expected to hit 100 degrees on
Sunday. Elsewhere on Sunday, highs will generally be several degrees
above normal inland, but close to normal for the coastal areas and
western valleys due to the persistent marine layer. The ridge will
shift east on Monday as a weak closed low moves towards the region,
slowly moving through on Tuesday and finally passing east late
Wednesday or early Thursday. This will result in a couple degrees of
cooling each day through the middle of the week.

In addition to slightly cooler conditions and the potential for a
deeper marine layer Tuesday and Wednesday, a slight chance (15-18%)
of showers has been added to the forecast for portions of the
mountains. Current guidance has the best chances of showers
Wednesday afternoon for the San Bernardino, Riverside, and San Diego
mountains. Isolated showers are possible on Tuesday afternoon as
well, most likely in the San Bernardino Mountains. The incoming low
is expected to be weak, with minimal moisture associated with it.
Even with the moisture limitations, ensemble members of both the
ECMWF and GFS are showing the potential for showers with light
rainfall accumulations over the portions of the mountains. Overall,
there is moderate confidence in the rainfall forecast, both in
amounts and timing.

Guidance for the latter half of the week continues to be conflicting
with continued spread in the ensemble solutions regarding the
position of the East Pacific ridge and the potential for troughing
across the Western US. This creates a wide range of possibilities
for temperatures. Current forecast for high temperatures follows the
NBM which keeps conditions near to slightly below normal for areas
west of the mountains and above normal for the deserts.

&&

.AVIATION...
112020Z...Coast/Valleys...Mostly clear skies will continue this
afternoon for areas away from the coast as low clouds near 1200-1800
ft MSL stick near the coast. Low clouds will come back inland after
00Z Sunday filling most valleys of San Diego and Orange Counties
after 03Z Sun. Low to moderate confidence on cigs reaching the
Inland Empire tonight, best chance VCTY KONT.

Mountains/Deserts...Mostly clear with unrestricted VIS through this
afternoon and evening. SCT/BKN clouds over the mountains with bases
around 9000 ft MSL through this afternoon. Breezy west winds for
SD/RIV County mountain passes and deserts near 20-30 kts until 08Z
Sun.

&&

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

&&

.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...CO
AVIATION/MARINE...APR