265
FXUS66 KSGX 231018
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
318 AM PDT Thu May 23 2024

.SYNOPSIS...
Cooling through Saturday with gusty southwest to west winds for
the mountains and deserts with the strongest gusts on Friday
afternoon into Friday night. Night and morning coastal low clouds
will extend inland across all of the valleys and onto the lower
coastal slopes of the mountains with slower daytime clearing for
coastal areas. High pressure to the south will bring warming for
Sunday through Wednesday. The marine layer will become shallower
with night and morning coastal low clouds only extending inland
into portions of the valleys by the middle of next week.

&&

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

.SHORT TERM (Today through Saturday)...
A trough of low pressure moving inland through southern California
tonight and Friday will bring stronger onshore flow. The marine
layer will deepen, cooling will spread inland, and there will be
periods of gusty southwest to west winds for the mountains and
deserts with the strongest winds for Friday afternoon into Friday
night.

There is a coastal eddy early this morning. The marine layer has
deepened to around 3500 feet with coastal low clouds extending
inland across all of the valleys and onto the lower coastal slopes
of the mountains. Additional deepening to 4500 to 5000 feet is
expected for Friday night into Saturday morning with patchy
drizzle possible.

There will be gusty southwest to west winds for the mountains and
deserts with the stronger winds on Friday and Saturday and the
strongest winds for Friday afternoon into Friday night with the
stronger gusts to 40 to 50 mph and the strongest gusts in the
northern Coachella Valley below the San Gorgonio Pass to around 60
mph.

High temperatures today will cool a few degrees from those on
Wednesday. There will be greater cooling on Friday. The deserts
will continue to cool slightly on Saturday while the coast and
valleys warm slightly. With the cooling, high temperatures for the
mountains and inland valleys will be as much as 10 to 15 degrees
below average on Friday.

&&

.LONG TERM (Sunday through Wednesday)...
High pressure to the south will bring warming through the middle
of next week. The greatest warming is expected for Sunday and
Monday with slight additional warming for Tuesday and Wednesday.
With the warming, high temperatures on Wednesday will be around
average for the coast and valleys and around 5 degrees above
average for the deserts, mostly in the 80s for the Inland Empire
and the upper 90s to 104 for the lower deserts. The marine layer
will gradually decrease in depth with night and morning coastal
low clouds only extending inland into portions of the valleys by
the middle of next week.

&&

.AVIATION...
230915Z...Coast/Valleys/Foothills...Low clouds with bases 1900-2500
FT MSL extend through the foothills this morning. Locally reduced
vis where low clouds and terrain intersect. Scatter out 18-21z Thu
across inland areas, with CIGS remaining at the coast. Low clouds
progressing back inland after 23z Thu with slightly higher bases.

Mountains/Deserts...Clear skies with unrestricted VIS through
tonight. W-NW wind gusts of 20-35 kt over/east of mtns after 00z
Fri, with weak-mod up/downdrafts and LLWS over/east of the mtns.

&&

.MARINE...
Northwest winds gusting near 20 knots in the outer waters each
afternoon and evening Friday through Sunday.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from noon Friday to 2 AM PDT Saturday for San
     Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...17
AVIATION/MARINE...EA