FXUS66 KSGX 061642
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
942 AM PDT Mon May 6 2024

.SYNOPSIS...
Dry and warmer, with gusty winds from the west over the mountains
and into the deserts today and Tuesday. A brief bout of offshore
winds will occur Wednesday, leading to additional warmth west of
the mountains. Another gradual warming trend looks likely heading
into this weekend, with no precipitation in the foreseeable future
at this time.

&&

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

The cold low pressure system responsible for this past weekend’s
cool, breezy, and wet weather will continue pushing eastward
across the Rockies today as high pressure slowly nudges inland
from over the Pacific. Accordingly, the onshore flow will weaken,
setting the stage for a notably warmer day than yesterday. Highs
today look to climb 5-10 degrees warmer than yesterday’s at the
coast, about 10-15 degrees warmer across the inland valleys as
well as both the High and Lower Deserts, and upwards of 15-20
degrees warmer across the mountains. The warming trend generally
continues, albeit just by a few additional degrees, through
Tuesday afternoon for most locations. The marine layer will
gradually become more and more shallow during this time with low
clouds and fog sticking closer to the coast and western coastal
valleys.

There will still be gusty onshore winds over the mountains and
into the deserts in the afternoons and evenings both today and
Tuesday. With a weaker pressure gradient, the winds will
accordingly be weaker than yesterday. A weak low pressure system
passing through the Great Basin Tuesday and Tuesday night will
strengthen the pressure gradient again. With all this in mind,
wind gusts of 40-50 mph can be anticipated below mountain passes
and through wind-prone canyons during the traditional late
afternoon and evening hours.

The development of a very strong upper level low pressure system
over the Northern High Plains, and its influence expanding
westward as it strengthens, will cause a quick bout of offshore
flow on Wednesday. It will drop temperatures in the deserts by a
few degrees but will continue the warming trend for areas west of
the mountains. The offshore flow itself does not appear to be
overly impactful, with perhaps a few gusts of 30-35 mph in the
Santa-Ana-favored areas below passes and through canyons.

The forecast then gets a bit more murky from Thursday onward. The
aforementioned strong upper low will cause a larger-scale
troughing pattern to set in over SoCal. This will support a deeper
marine layer with clouds and fog extending farther inland.
Temperature trends during this time look to be highly dependent on
marine layer coverage and duration of low clouds each
morning/afternoon. Eventually the low and attendant trough look to
weaken which would support another gradual warming trend, though
exactly when that will take place appears uncertain at this time.


&&

.AVIATION...
061630Z...Coasts/Valleys/Foothills...Mostly clear conditions with
unrestricted visibilities through this evening. Areas of low clouds
to redevelop in coastal areas after 06Z into Tuesday morning, with
bases around 1200-1800 feet MSL.

Mountains/Deserts...Mostly clear conditions with unrestricted
visibilities will prevail over the next 24 hours.

&&

.MARINE...
No hazardous marine conditions are expected today through Friday.

&&

.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...Adams
AVIATION/MARINE...Suk