373
FXUS66 KSGX 041005
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
305 AM PDT Tue Jun 4 2024

.SYNOPSIS...
High pressure aloft will continue the inland warming trend with
the heat peaking on Thursday and Friday with high temperatures for
the mountains and deserts generally 8 to 12 degrees above average,
exceeding 105 in portions of the Apple and Lucerne Valleys and 110
in the lower deserts. The marine layer will keep coastal areas
cooler with night and morning coastal low clouds not spreading as
far into the valleys for or Thursday and Friday. Then gradually
cooler for Saturday through Monday, but with Monday high
temperatures still around 5 degrees above average for the deserts.
This may be followed by lesser inland warming for Tuesday and
Wednesday of next week.

&&

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

.SHORT TERM (Today through Thursday)...
High pressure aloft over California will continue the strong
inland warming trend into Thursday with Thursday high temperatures
generally 8 to 12 degrees above average for the mountains and
deserts, exceeding 105 in portions of the Apple and Lucerne
Valleys and 110 in the lower deserts.

While inland areas will have their hottest weather so far this
year, it is mostly not expected to be recording setting with
greater chances for warm overnight temperatures to break or tie
records than for daytime high temperatures to tie or exceed
existing records.

The marine layer will become gradually shallower into Thursday and
Friday. Night and morning low clouds extending well into the
inland valleys overnight may only reach the western valleys for
Thursday and Friday. The marine layer will also moderate the
warming toward the coast with high temperatures near the coast
only a few degrees above average for Thursday and Friday, mostly
in the upper 60s.

&&

.LONG TERM (Friday through Monday)...
High pressure aloft will begin to weaken for the weekend into
early next week with a gradual cooling trend. Even with the
cooling, high temperatures for the deserts will still be around 5
degrees above average on Monday, still exceeding 105 for the lower
deserts. This may be followed by lesser warming for Tuesday and
Wednesday of next week. Slow deepening of the marine layer is
expected with night and morning coastal low clouds spreading
farther into the valleys by Sunday and Monday.

&&

.AVIATION...
040930Z...Coast/Valleys...Low clouds with bases 1300-1800 feet MSL
with tops to 2200 feet will continue to move inland and extend into
portions of inland valleys through 14Z. Vis 1-5SM inland, where low
clouds and terrain intersect. Scatter out 16-20Z, with only partial
or intermittent clearing at the coast. Low clouds to push ashore
after 00Z and locally into valleys overnight into Wednesday. Bases
around 1000-1500 feet MSL and inland vis reduced.

Otherwise...Gradually decreasing high clouds today and mostly
clear tonight.

&&

.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 Warning from 10 AM Wednesday to 9 PM PDT Friday
     for Apple and Lucerne Valleys-Coachella Valley-San Diego
     County Deserts-San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

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