982
FXUS66 KSGX 021557
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
857 AM PDT Thu May 2 2024

.SYNOPSIS...
Periods of low clouds and fog are expected each day west of the
mountains, most widespread in the nights and mornings. A passing
weather system to our north will increase cloud coverage for inland
areas this weekend. That system will also bring gusty winds to the
mountains and deserts, cooler conditions, and periods of showers to
areas over and west of the mountains. Drier and warmer conditions
are expected through the middle of next week.

&&

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

A robust eddy is spinning along the coast this morning, which is
helping marine layer low clouds and fog surge inland. At 8 AM, low
clouds continue to surge inland, almost filling in the coastal
basin. The inversion on the 12Z sounding is a few degrees stronger
than yesterday`s (about 8 degrees vs 5 degrees yesterday). Low
clouds should eventually clear the valleys but could stick along the
beaches this afternoon. Low clouds are expected to spread into much
of the coastal basin overnight into Friday morning and again Friday
night into Saturday morning.

A low pressure system will move into the Pacific Northwest Saturday,
before digging south in the Great Basin Sunday. This will increase
onshore flow for Southern California this weekend and as a result
cloud coverage (especially for the valleys and mountains) will be
more persistent, high temperatures will take a dip, winds will
increase, and areas of showers are expected. Periods of gusty
westerly winds over the mountains, through passes, and into the
deserts will be the main weather hazard. Winds will begin to
increase Saturday afternoon, peak Saturday night into Sunday, before
slowly decreasing into Sunday evening. For Saturday night into
Sunday morning along the desert slopes of the mountains and adjacent
desert areas, peak gusts of 55 to 65 mph are expected.

Periods of mostly light precipitation are expected for places in and
west of the mountains. Coverage of the precipitation will be showery
with the best chances of showers in the mountains, the Inland
Empire, and west of the mountains in San Diego County. This is a
fast moving system and current timing has shower activity
occurring Saturday night into Sunday morning. Rainfall totals of
a one-tenth inch or less are expected for the coast and valleys
with up to one- quarter inch of rain for the coastal mountain
slopes. A trace of snow is possible above 7500 ft.

High temperatures will be fairly similar between today and tomorrow,
with highs near to slightly above average. Cooling conditions are
expected Saturday, with further cooling expected on Sunday. On
Sunday highs will be 10 to 15 degrees below average for inland
areas. Monday will be dry and much warmer, around 5 degrees warmer
at lower elevations to 8 to 12 degrees warmer for the mountains with
not much change for Tuesday and Wednesday, generally a few to around
5 degrees below average.

&&

.AVIATION... 021530Z...Coasts/Valleys...Low clouds with bases 1400-
1800 feet MSL, tops to 2500 feet and inland vis 1-5SM will gradually
scatter out by 17-19Z, but patchy and intermittent BKN clouds could
linger near the coast thereafter. Low clouds spreading back inland
after 02Z with bases 1400-2000 feet MSL with a similar cloud
coverage inland. Scatter out Friday 17-19Z.

Otherwise, clear skies with unrestricted vis through Friday
morning.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday
morning. Gusty west to northwest winds late Saturday 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