Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
200 PM PDT Tuesday Jun 2 2015
Synopsis...seasonally cool weather will continue west of the
mountains this week. Low clouds will cover much of the coastal basin
during the nights and mornings...with drizzle or sprinkles possible
each morning. Gusty westerly winds will occur each afternoon and
evening through the passes and onto the desert slopes. Moisture from
the remnants of Hurricane Andres could also bring a few high clouds
late in the week...and buildups or even isolated showers are
possible over the mountains Saturday afternoon. For Sunday through
early next week...expect a shallower marine layer and a warming
trend inland. There is also a small chance early next week for
moisture from the remnants of tropical cyclone Blanca to spread into
portions of Southern California.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Mostly clear this afternoon...except for some low clouds lingering
at the beaches. Surface pressure gradients remain onshore with 6.0 mb
san-dag and 6.3 mb san-ipl...producing locally breezy conditions in
the mountains and adjacent desert areas.
From previous discussion...through Thursday...broad troughing over
the West Coast with shortwaves moving through the mean flow will
bring general deepening of the marine layer with some variations in
the inland extent of the low clouds and fog during the nights and
mornings. With a deeper marine layer...drizzle or sprinkles will be
possible each morning. Moderate onshore flow will continue to bring
gusty west winds to locations in the mountains and on adjacent desert
slopes during the afternoons and evenings. Daytime temperatures
should be near or a little below seasonal averages in the coastal
areas...and slightly above averages elsewhere.
For Friday and Sat...global deterministic models have now arrived at a
consesus on the track and timing of a low pressure system developing
over the coast of central California and moving south along the
coastline. For our portion of socal...this is a dry solution which
shows only modest entrainment of moisture from the remnants of
Andres and keeps most if not all of the precipitation to our south and
east. Some low-level moisture and modest instability could bring
buildups or even isolated showers over the local mountains Sat afternoon.
For sun through early next week...onshore flow weakens as the low
pressure system weakens and moves to the NE. This will bring a
shallower marine layer and a warming trend inland. There is also a
small chance that some of the moisture from the remnants of Blanca
could reach portions of Southern California next Monday and Tuesday.
However...this is looking less likely now.
022030z...low clouds have dissipated but areas remain on the
immediate coast and beaches. There was one additional surge of low
clouds with the stronger sea breeze at midday. There is a remnant
eddy low pushing another area towards Oceanside now. There should be
a quick return this evening between 00 and 04 UTC with a slightly
deeper remain layer later overnight and bases starting 1000-1500
feet in the MVFR category. Minor cooling of about 1c occurs at 850
mb layer and a short wave trough crosses Southern California tonight
for help in deepening the inversion. This is ahead of the main upper
low prognosticated to dig toward the California bight starting Thursday.
130 PM...no hazardous marine weather is expected through Saturday.
130 PM...southerly swell from weakening Hurricane Andres and
strengthening Hurricane Blanca will continue and increase on
Wednesday with larger surf and stronger rip currents into Thursday
..particularly in Orange County. See surf forecast for
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.