674
FXUS66 KSGX 241607
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
907 AM PDT Fri May 24 2024

.SYNOPSIS...
Cooling will continue through Saturday with gusty southwest to
west winds in the mountains and deserts. The strongest gusts occur
this afternoon and evening with the stronger gusts to 40 to 50
mph, locally 60 to 65 mph below the San Gorgonio Pass. 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 Thursday. The marine
layer will become shallower with night and morning coastal low
clouds only extending into western 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...

A deep marine layer is evident on visible satellite imagery this
morning, with clouds extending all the way over the Cajon Pass as of
9 AM PDT. The 12z Miramar sounding indicated a saturated layer from
roughly 1800-2000 FT MSL to about 3000-3500 FT MSL. A strong
inversion is also noted near the top of the saturated layer, roughly
9C strong. Given these observations, its fair to assume that the
low clouds will be hanging around over the coasts and inland valleys
for much of this morning and afternoon.

Short-term guidance suggests some slow clearing over the Inland
Empire this afternoon, but most areas closer to the coast will
likely see intermittent clearing, at best. This trend is expected to
continue into Saturday with persistent onshore flow in place. The
marine layer looks to deepen to around 4500 feet tonight, which will
likely support patchy drizzle into tomorrow morning. The onshore
flow is expected to be strongest today, with winds gusting 40 to 50
mph across much of the mountains and deserts this afternoon and
evening. Higher gusts look to occur through and just below the San
Gorgonio Pass, where gusts of 60 to 65 mph are expected.

Sunday kicks off a warming trend for SoCal as upper level ridging
builds in overhead. Highs will climb several degrees both on Sunday
and Monday, followed by slower and more gradual warming through
midweek. Most areas will still remain slightly cooler than normal
through midweek, but the lower deserts will top out a few degrees
warmer than seasonal normal starting Monday. This translates to
highs of 99 to 105 degrees each day Monday through Thursday, with
Wednesday and Thursday being the warmest days in the lower deserts.
For most other locations, Wednesday and Thursday will be when
temperatures rebound back to seasonal normals. The marine layer will
also steadily decrease in depth during this time, though there will
still be some degree of marine layer clouds each morning over the
coasts and valleys.


&&

.AVIATION...
241600Z...Coast/Valleys/Foothills...BKN-OVC with bases 1800-2500 FT
MSL extend through the foothills this morning and early afternoon.
Locally reduced vis where low clouds and terrain intersect. Partial
clearing across inland areas 18z-21z Fri and across the coast 19z-
22z Fri with bases rising abv 2500 FT MSL. Low clouds spreading back
inland starting 02Z Sat.

Mountains/Deserts...FEW-SCT AOA 25,000 FT MSL through Fri night. W-
SW wind gusts of 25-40 knots over/east of mtns after 21z Fri,
strongest after 00z Sat. Locally reduced vis of 3-5 SM in local BLDU.

&&

.MARINE...
Northwest winds near 20 knots will occur in the outer coastal waters
each afternoon and evening 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 until 2 AM PDT Saturday for San Gorgonio Pass Near
     Banning.

PZ...None.

&&

$$

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