812
FXUS66 KSGX 012021
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
121 PM PDT Wed May 1 2024

.SYNOPSIS...
A shallower marine layer, with warmer conditions expected for
Thursday and Friday. A passing low pressure system will bring
increased cloud coverage, cooler conditions, periods of gusty
westerly winds, and a slight chance of precipitation to the area
Saturday into Sunday. Drier and warmer conditions expected early
next week.

&&

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

A coastal eddy is expected remain present over through at least
Saturday, which will help maintain areas of night and morning low
clouds and fog. Even with the eddy the marine layer is expected to
get shallower tonight and Friday night. Low clouds and fog are
forecast to reach into the valleys, but are not expected to
completely fill in the coastal basin.

Conditions are expected to warm a few degrees Thursday with another
warm day expected on Friday. On Saturday, an incoming low pressure
system is expected to push the weak ridge over us to the east. This
will bring a few degrees of cooling for Saturday, with even more
cooling on Sunday as the low digs into the Great Basin. Highs on
Sunday are expected to be 5 to 10 degrees cooler than Saturday west
of the mountains and 10 to 15 degrees cooler than Saturday in the
mountains and deserts. Monday and Tuesday are expected to be warmer,
but highs will still be below average on Tuesday.

The onshore pressure gradient will increase over the weekend
enhancing westerly winds over the mountains, through passes, and
into the deserts. There is still some uncertainty in the strength of
the winds but there is 30-40 percent chance of wind gusts between 40-
60 mph, with a 20 percent chance of gusts exceeding 60 mph. The most
likely place for gusts to exceed 60 mph are through passes and
canyons, like the San Gorgonio Pass. Winds will peak in strength
late Saturday into Sunday afternoon before decreasing Sunday night
into Monday.

The passing low will dig far enough south to bring chances of
precipitation to Southern California Saturday night into Sunday.
Rainfall is expected to be mostly light and confined to areas in and
west of the mountains. Highest chances of precipitation Saturday
night into Sunday are in the mountains at 30-45 percent, chances for
the coast and valleys are mostly 15-25 percent. Highest rainfall
totals will likely be in the mountains, with a 30-40 percent chance
of a quarter of an inch or more accumulating. For the coast and
valleys, rainfall totals will most likely be less than 0.20 inch.
Dry conditions are expected to return by Monday.

&&

.AVIATION...
012030Z...Coasts/Valleys...Areas of BKN low clouds based at 2500-
3500 feet MSL will persist in the coastal strip just inland from
beaches. BKN low clouds with bases 1800-2500 feet MSL and tops to
3000 feet will redevelop and spread inland after 03Z, but only into
portions of inland valleys. Bases and tops will continue to lower
into Thursday morning. Local vis restrictions 2-5SM inland. Scatter
out Thursday by 15-17Z.

Otherwise, clear skies with unrestricted vis through Thursday.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday
morning. Gusty northwest winds Saturday evening through Sunday are
likely to generate hazardous boating conditions, especially in the
outer waters.

&&

.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...MM