230
FXUS66 KSGX 111616
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
916 AM PDT Sat May 11 2024

.SYNOPSIS...
Low clouds and fog expected each night and morning for the coast and
valleys through the next week. A few degrees of warming is
expected today and Sunday, with cooling Monday and Tuesday. There
is some uncertainty in the forecast for the latter half of next
week, but an inland warming trend looks likely.

&&

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

At 9 AM, low clouds were steadily clearing from the valleys towards
the coast. The inversion on the 12Z sounding at KNKX was about 9
degrees, so while low clouds will likely clear most inland and
coastal areas there is lower confidence in complete clearing at the
beaches today. If low clouds do clear the beaches, it`ll likely be
intermittent and late in the afternoon. Night and morning low
clouds and fog are expected to remain present each day through
next week. Some fluctuation on how far inland low clouds push each
night is expected, with a lesser inland extent for the next
couple of days and a deeper marine layer possible towards the
middle to end of next week.

Weak ridging will set up over Southern California today and Sunday
as an upper level low near the Four Corners region continues to push
east. This will allow for a brief warming trend, most noticeable for
inland areas. Highs in the lower deserts are expected to hit 100
degrees by Sunday. Elsewhere on Sunday, highs will generally be
several degrees above normal inland, but close to normal for the
coastal areas and western valleys due to the persistent marine
layer. The ridge will shift east on Monday as a weak closed low
moves towards the region, slowly moving through on Tuesday and
finally passing east by Wednesday. This will result in a couple
degrees of cooling each day.

The pattern becomes more iffy beyond Wednesday as there continues to
be much spread in the ensemble solutions regarding the position of
the East Pacific ridge and the potential for weak troughing
somewhere in the vicinity of Southern California, or potentially
even a long wave trough across the Western US for the latter part of
the week. This creates a wide range of possibilities for
temperatures. Current forecast for high temperatures remains
around the 50th percentile of the guidance which keeps conditions
within a few degrees of normal for areas west of the mountains and
above normal for the deserts.

&&

.AVIATION...
111600Z...Coast/Valleys...Low clouds with bases 1000-1800 ft MSL,
and tops near 3000 ft MSL are scattering out of portions of the
Inland Empire and SD Co foothills this morning. Clearing will
continue across coastal valleys 17-19Z. Confidence is moderate to
high on FEW-SCT conditions at all coastal TAF sites 18-19Z, with
moderate confidence in SCT-BKN conditions remaining near the beaches
through the afternoon hours.

Low clouds look to push back inland between 00-03z Sun, reaching
more of the coastal valleys by 06-09z. Cigs expected to be a few
hundred feet lower than this morning with patchier coverage across
northern and eastern areas of the Inland Empire by Sunday morning.

Mountains/Deserts...Mostly clear with unrestricted VIS through this
morning. SCT/BKN clouds over the mountains with bases around 9000 ft
MSL Sat afternoon. Breezy west winds for SD/RIV County mountain
passes and deserts near 20-30 kts at times.

&&

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

&&

.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...CO
AVIATION/MARINE...APR