735
FXUS66 KSGX 091624
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
925 AM PDT Thu May 9 2024

.SYNOPSIS...
Marine layer clouds west of the mountains will clear back to near
the coast each afternoon through Sunday. High temperatures west of
the mountains will be similar each day through Sunday, while the
mountains and deserts will see a few degrees of warming over the
weekend.

&&

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

The marine layer depth on the 12Z NKX sounding this morning was
3,000 ft, 600 feet deeper than Wednesday morning, and the low clouds
had spread several miles farther into the valleys at sunrise. Clouds
with this deeper marine layer will be slower to clear back to the
coast than yesterday, and may linger at some of the beaches this
afternoon.

The coastal eddy responsible for the deeper marine layer will weaken
tonight and then dissipate entirely on Friday. As a result, the
marine layer will not be as deep over weekend and the low clouds
will not spread as far into the valleys.

High temperatures west of the mountains will be fairly consistent
with coastal highs from 65-75 and valley highs from 75-85. Mountains
highs in the 60s today will warm into the 70s by Sunday. High desert
highs in the mid 70s today will warm into the mid 80s by Sunday, and
in the lower deserts, highs near 90 today will heat up to near 100
on Sunday.

This temperature regime continues Monday through Wednesday when a
weak Pacific trough moves inland across Southern California.

&&

.AVIATION...
091605Z...Coast/Valleys...Low clouds beginning to clear inland at
this hour. Bases are 2000-2500 ft MSL with tops near 4000 ft MSL.
Higher terrain obscured with VIS 1-3SM where clouds and terrain
intersect. The valleys should clear by 18Z then partial clearing at
the coast 18Z-20Z. Local BKN conditions at the beaches into the
afternoon. Low clouds will move ashore after 02Z, spreading inland
tonight with very similar bases/vis and overall coverage by Friday
morning.

Mountains/Deserts...Clear skies with unrestricted VIS through
tonight.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...Moede
AVIATION/MARINE...PG