Area Forecast Discussion
Issued by NWS San Diego, CA
FXUS66 KSGX 311003
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
303 AM PDT TUE MAY 31 2016
High pressure aloft will strengthen over California bringing an
inland warming trend with high temperatures for inland areas
warming to 15 to 20 degrees above average for Friday and
Saturday. The marine layer will become shallower into next
weekend. Areas of night and morning coastal low clouds and patchy
fog will not extend as far inland for the latter part of the week
with limited or slow afternoon clearing for some beaches. For next
Sunday and Monday...a weak low pressure system will move into
California bringing a cooling trend and deepening of the marine
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
High pressure aloft just off the California coast will strengthen
and move slowly inland through Saturday. This will bring an inland
warming trend with high temperatures for inland areas that were
around 10 degrees below average on Sunday...warming to 15 to 20
degrees above average for Friday and Saturday. This will push
high temperatures in portions of the inland empire above
100...above 105 in portions of the upper deserts...and above 110
in the lower deserts. An Excessive Heat Watch has been issued for
Friday and Saturday for the deserts and inland valleys. The marine
layer and weak onshore flow will keep areas near the coast cooler
with high temperatures 5 to 10 degrees above average for Friday
and Saturday with high temperatures near the coast mostly in the
The marine layer is not quite as deep as 24 hours ago...but is
still near 2500 feet deep with cloud bases near 1000 to 1500 feet
above mean sea level. This is sufficient for the low clouds to
extend into the far inland valleys this morning. So far there have
been no measurable precipitation amounts overnight...but some
patchy drizzle is still possibly early this morning...once again
mainly for coastal and valley areas of San Diego County.
Through this week...the marine inversion will gradually strengthen
and lower with the night and morning coastal low clouds and patchy
fog not extending as far inland and with limited or slow afternoon
clearing at some beaches.
For next Sunday and Monday...a weak low pressure system will move
inland through California bringing a cooling trend and deepening
of the marine layer.
310900Z...Coast/Valleys...Clouds will fill most of the coastal basin
by sunrise. Bases will be around 1200-1500 feet msl with tops to
2500 feet. Scatter out is expected in valleys by 16-17Z and at
coastal airports by 18Z. Low clouds with similar bases and tops will
develop and move ashore after 02Z this evening and head into some of
the inland valleys overnight.
Mountains/Deserts...Mostly clear skies with unrestricted visibility
today and tonight.
200 AM...No hazardous marine weather is expected through Saturday.
200 AM...A south swell will begin to build today, peak Wednesday and
Thursday, and diminish Friday. The long period of this swell will
help to produce surf bigger than average Wednesday and Thursday
particularly for south facing beaches. Strong rip and longshore
currents can be expected. For details, check the Beach Hazards
Statement (LAXCFWSGX) along with the surf forecast (LAXSRFSGX).
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
CA...Excessive Heat Watch from Friday afternoon through Saturday
evening for Apple and Lucerne Valleys-Coachella Valley-San
Bernardino and Riverside County Valleys-The Inland Empire-
San Diego County Deserts-San Gorgonio Pass Near Banning.
Beach Hazards Statement from Wednesday morning through Thursday
evening for Orange County Coastal Areas-San Diego County