632
FXUS66 KSGX 130401
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
901 PM PDT Wed Jun 12 2024

.SYNOPSIS...
Marine layer night and morning low clouds and fog will persist
along the coast, into the valleys at times, each day into next
week. Tomorrow is expected to be a few degrees cooler than today
for most locations. Another bout of warming is expected for Friday
and Saturday, most noticeable in the lower deserts. Seasonal to
slightly below average temperatures will return Sunday through the
middle of next week. Periods of gusty southwest to west winds are
expected in the mountains and deserts each afternoon and evening
into next week. Gusty westerly winds combined with dry and hot
conditions in the deserts and desert mountain slopes will create
elevated fire weather conditions through the weekend.

&&

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

Update...
The 00z Miramar sounding showed a 5.5C degree inversion based near
1100 feet, quite a bit more shallow than the observed sounding
from this morning. Low clouds are moving inland across San Diego
County coastal areas, and will fill in across Orange County in the
next few hours. Patchy drizzle will be possible overnight and
tomorrow morning.

A weakening upper low will pass over the region tomorrow,
promoting slight cooling. Warmer for Friday and Saturday, with
moderate to locally high heat risk developing in the deserts.

Previous Discussion (Issued 132 PM PDT Wed Jun 12 2024)...
Visible satellite at 1 PM this afternoon showed a few patches of low
clouds lingering along portions of the northern San Diego and
southern Orange County coast. Low clouds are expected to fill inland
overnight again tonight, reaching into portions of the valleys, with
periods of patchy drizzle. A similar clearing pattern is expected
tomorrow, with low clouds clearing inland but locally lingering at
beaches in the afternoon.

A weak low pressure system will move inland through southern
California late Thursday. As a result, a few degrees of cooling are
expected for most areas Thursday. The cooling trend will be brief as
a weak high pressure system sets up over southeastern California,
southern Nevada, and western Arizona Friday and Saturday. For
Friday, highs will be a degree or two warmer for the coast and 2-6
degrees warmer for the valleys, mountains, and deserts. Warming will
continue into Saturday, which will be the peak of this brief warming
trend. Highs are expected to be 3-7 degrees above average for the
coast and western valleys and 6-12 degrees above average for
portions of the eastern valleys, mountains, and deserts. Moderate to
locally major heat risk is expected in the low deserts, with ares of
moderate heat risk in the Inland Empire, mountains, and High Desert.
During this time its recommended that folks stay hydrated and limit
outdoor physical activities between 10am and 5pm.

A low pressure system moves inland through the western states Sunday
into the middle of next week, bringing seasonal to slightly below
average temperatures to the area. Cooling conditions are expected
for most areas Sunday and Monday, with a few degrees of warming
expected by Tuesday. The increase in onshore flow with the passing
trough will also allow for the marine layer to deepen again with low
clouds reaching into the valleys.

&&

.AVIATION...
130310Z...Coast/Valleys...BKN-OVC010-013 tops 018 through 05Z
lowering to 005-010 through 15Z with areas VIS 2-4SM in FG/HZ.
Clouds/fog may reach as far inland as KONT at 12Z but not likely to
reach KSBD. Clouds clearing from the valleys through 18Z, and from
the coastal areas 19-23Z.

Mountains/Deserts...SKC with unrestricted VIS.

&&

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

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Watch from Friday morning through Saturday
     evening for Coachella Valley-San Diego County Deserts-San
     Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...EA
AVIATION/MARINE...Moede