071
FXUS66 KSGX 071612
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
912 AM PDT Fri Jun 7 2024

.SYNOPSIS...
There will be a slow cooling trend through Sunday. Minor
fluctuations in daily temperatures and marine layer depth then
follow for much of next week. The marine layer will mostly
fluctuate between 2000 and 2500 feet deep, keeping coastal areas
cooler with night and morning coastal low clouds extending inland
into portions of the valleys. There will also be slightly stronger
onshore flow this weekend, with gusty southwest to west winds for
the mountains and deserts each late afternoon and evening.

&&

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

Marine layer clouds are beginning to slowly clear out over the
Inland Empire as of 9 AM PDT. The 12z Miramar sounding indicated
a saturated layer from near the surface to around 2000 FT MSL, the
depth of which has supported areas of drizzle this morning. An
upper level low is also sitting off the southern Baja coast,
acting to send some high-level clouds into SoCal. High pressure
over the western US will weaken through the weekend while the
current Baja low opens up into a wave and moves inland.
Meanwhile, another upper level low pressure system will form
offshore this weekend. There will accordingly be a slight and
gradual cooling trend this weekend, but generally only on the
order of 2-5 degrees each day for most locations. Highs will flip
to being several degrees cooler than seasonal normal while the
deserts slowly fall back to seasonal average by Sunday and Monday.

Marine layer clouds will cover much of the coastal basin well
into the late mornings and afternoons (location dependent) each
day through the weekend. The developing low off the SoCal/northern
Baja coast this weekend will maintain onshore flow through next
week, which will support a deep marine layer each day and will
also lead to gusty winds over the mountains and deserts each
afternoon and evening. The strongest gusts are expected in the
northern Coachella Valley below the San Gorgonio Pass, with gusts
to around 45-55 mph. Wind gusts of 30-40 mph can be expected
elsewhere for the desert mountain foothills.

The weak upper low off the SoCal/northern Baja coast then looks to
remain in place for much of next week, perhaps eventually opening
up into a wave and moving inland sometime around Thursday or
Friday of next week. Very minor fluctuations in temperatures and
marine layer depth is expected during this time, so an abundance
of June Gloom and slightly cooler temperatures look likely for
next week.

&&

.AVIATION...
071605Z...Coast/Valleys...Low clouds with bases 600-1100 feet MSL
and tops to 2000 feet MSL clearing at the inland edges this hour.
Vis 1-3SM in fog on higher coastal terrain and in the valleys.
Inland clearing through 19Z but very little if any clearing at the
coast. Low clouds will spread inland again after 00Z with slightly
higher bases and tops, filling the coastal basin by 13Z Saturday.
Higher terrain obscured with VIS 1-3SM in fog where clouds and
terrain intersect. Expect inland clearing 16Z-18Z Sat and partial
clearing at the coast 18Z-21Z Sat.

Elsewhere...FEW-SCT250 and unrestricted VIS through tonight.

&&

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

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning until 9 PM PDT this evening for Apple and
     Lucerne Valleys-Coachella Valley-San Diego County Deserts-
     San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...Adams
AVIATION/MARINE...PG