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000
FXUS66 KSGX 230948
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
248 AM PDT Tue May 23 2017

.SYNOPSIS...
High pressure aloft will bring the hottest temperatures of the
week for desert areas today. Coastal areas will be cooler with
areas of night and morning low clouds and fog spreading into the
far western valleys this morning...and farther into the valleys
for Wednesday morning with slow cooling spreading inland. A trough
of low pressure over the western states will bring stronger
onshore flow and greater cooling for Thursday and Friday with
strong gusty southwest to west winds in the mountains and deserts.
The marine layer will deepen with low clouds extending into the
far inlands Thursday morning...and onto the coastal mountain
slopes for late Thursday night into Friday morning with a slight
chance of light showers along and west of the mountains. High
pressure aloft near the West Coast will bring a warming trend for
the holiday weekend with high temperatures for inland areas
warming to near average on Sunday and a little above average on
Memorial Day. The marine layer and weak onshore flow will keep
coastal areas cooler with areas of night and morning low clouds
and fog.

&&


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

High pressure aloft near the West Coast will peak today with the
warmest high temperatures of the week for inland areas. High
temperatures around 110 are expected for the lower deserts. For
coastal areas...the marine layer continues to slowly deepen and is
around 200 feet deeper than 24 hours ago with satellite imagery
showing low clouds extending inland to the far western valleys in
San Diego County. Continued slow deepening is expected to take
the low clouds a little farther into the western valleys for
tonight into Wednesday morning. Slow cooling will spread into the
western valleys today...and into the deserts on Wednesday.

For Thursday and Friday...low pressure over the western states
will bring stronger onshore flow with cooling to around 10
degrees below average for inland areas...with Friday expected to
be the coolest day. There will be periods of strong gusty
southwest to west winds in the mountains and deserts. Greater
deepening of the marine layer will take coastal low clouds
into the inland valleys on Thursday morning...and onto the
coastal mountain slopes for late Thursday night into Friday
morning with a slight chance of light showers along and west of
the mountains. Any precipitation is expected to be light.

For the holiday weekend...high pressure aloft near the West Coast
will bring a warming trend with high temperatures for inland area
warming to near average on Sunday and a little above average on
Memorial Day. The marine layer and weak onshore flow will keep
coastal areas cooler with areas of night and morning low clouds
and fog.

&&

.AVIATION...
230900Z...Low clouds with bases around 800 feet msl and tops to 1400
feet will continue through 16Z at coastal airports. Vis may be
reduced to 3-5sm or lower on higher coastal terrain. Low clouds will
move ashore this evening after 04Z. These clouds will be based at
around 1000 feet msl and spread farther inland overnight. Otherwise,
mostly clear skies except for a few high clouds and afternoon
cumulus over the mountains.

&&

.MARINE...
No hazardous marine weather is expected through Saturday.

&&

.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...17
AVIATION/MARINE...MM