Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
120 PM PDT Tuesday Sep 1 2015
an upper-level trough along the West Coast will continue fair
and cooler weather this week...with night/morning coastal low
clouds/fog extending far into the valleys. Locally gusty west winds
will develop each afternoon/evening along Desert Mountain slopes
and through mountain passes. Slightly warmer this weekend...with a
more shallow marine layer.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
The 01/1200 UTC European model (ecmwf) and GFS are in relatively good agreement
through the long-term.
At 1 PM PDT...water vapor satellite imagery displayed an upper-
level trough along the West Coast...a very weak upper-level low
around 230 miles SW of Point Conception...and a weak upper-level
ridge over western Texas. Visible satellite showed high clouds over
the region...and some low clouds over the coastal waters.
The trough along the coast will dominate the weather over SW California
through the rest of the work week...and pull in dry air from the
southwest through the period. Lowering heights through Friday
will create a deep marine layer...with night/morning low
clouds/fog developing well inland into the valleys and reaching
the coastal mountain slopes each night. Onshore surface pressure
gradients from the coast to the California/Arizona border near 5 mb will create
westerly wind gusts near 45 miles per hour through mountains passes and along
Desert Mountain slopes each afternoon and evening. Highs will be
near normal along the coast and in the high deserts...and range
from 5 to 20 degree f below seasonal normals for other inland
areas...especially in the Temecula/Murrieta area.
Heights will build slightly over the weekend...with another trough
anchoring along the West Coast early next week. This will help to
create a moderate marine layer...and raise forecast high
temperatures closer to seasonal normals.
012000z...coast/valleys... sct025-030 bkn200 at the coast
this afternoon becoming broken-ovc025-030 tops 035 this evening and
spreading into the inland valleys through 15z Wednesday.
Visibilities will be p6sm at the the coastal airports. Lower
visible of 4-6sm near the foothills where clouds intersect terrain.
Skies clearing back to the coast between 15-19z Wednesday.
Mtns/deserts...sct-bkn200 with unrestricted visible through Wednesday.
100 PM...no hazardous marine weather is expected through Saturday.
100 PM...south-southwest swells from Hurricane Jimena will produce
elevated surf and strong rip currents to so-cal beaches tonight and
Wednesday...easing a bit on Thursday and Friday. Highest surf of
2-4 feet will occur tonight and Wednesday with maximum sets to 5 feet on
southwest facing beaches.
This weekend a fresh south swell from Tropical Depression Fourteen-east
has the potential to bring even higher surf to so-cal beaches.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.