Area Forecast Discussion
Issued by NWS San Diego, CA
FXUS66 KSGX 300416
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
916 PM PDT SUN MAY 29 2016
For Monday through Thursday, expect an inland warming trend and a
gradually shallower marine layer with areas of night and morning
coastal low clouds and patchy fog not extending as far inland.
There is a slight chance of light rain again overnight through
Monday morning. For next weekend, another weak low pressure
system will move inland bringing cooling and a deeper marine
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
Isolated showers and thunderstorms have dissipated over the
mountains this evening. The marine stratus that was extremely slow
to clear west of the mountains today is already beginning to fill
back in, and will blanket the coastal and valley areas overnight.
The base of the marine inversion has dropped from around 3700 ft
this morning to 3100 ft this afternoon, so expect inland extent
to be slightly less. However, the marine layer remains
sufficiently deep to produce some drizzle or light showers
tonight, though any accumulation will be around a couple
hundredths inch at best. Further inland, breezy conditions will
prevail in the mountains and deserts through the late evening.
The upper level low that was over Southern California today will
slowly drift southeast over the next few days, allowing an upper
level ridge to build over the Western U.S. This will bring gradual
warming, especially inland, through Thursday. The marine layer
will become more shallow each day, though with the building ridge
the inversion will remain quite strong. Low clouds and patchy fog
will not spread as far inland each night, but the beaches may
remain cloudy for much of the week. June Gloom will certainly live
up to its name close to the coast. Elsewhere benign weather will
A closed low very slowly drifts towards Southern California Friday
through the weekend for cooler weather, a deeper marine layer, and
gusty onshore winds in the mountains a deserts. The GFS tries to
pull up some subtropical moisture with the low on Saturday, though
it`s mostly above 500 mb. The ECMWF is slightly drier and keeps
the moisture above about 400 mb. The sub- cloud layer is quite
dry, so it would be hard for any possible precip to reach the
ground, except for maybe the highest peaks of the San Bernardino
and San Jacinto mountains. Will continue to monitor, but for now
have left the forecast dry.
300415Z...Coast/Valleys...Areas of BKN-OVC stratus will occur with
greatest coverage within 25 mi of the coast overnight. Ceiling
heights will be variable, generally 1800-3300 ft MSL with tops to
3500 ft MSL. Higher terrain will be obscured at times, but vis below
the cloud bases will mostly remain 6+ miles. Valleys will clear 16Z-
18Z Monday with most coastal areas clearing 18Z-20Z Monday. Stratus
have less coverage and be closer to the coast Monday night. Overall
confidence is moderate.
Mountains/Deserts...Mostly clear skies with unrestricted vis will
prevail through Monday night.
915 pm...No hazardous marine conditions are expected through
Skywarn activation is not requested at this time. However, weather
spotters are encouraged to report significant weather conditions.