Scientific Forecaster Discussion
Southwest California area forecast discussion...update
National Weather Service Los Angeles/Oxnard California
510 PM PDT Thursday Aug 27 2015
..updated aviation discussion...
High pressure and offshore flow will bring above normal temperatures
through Saturday. The high will weaken Sunday for a cooling trend
and below normal temperatures by middle next week. An upper level
trough over the West Coast will bring increasing onshore flow and
spread coastal clouds and fog inland each night through morning next
Short term (fri-sun)... another hot day across the area as the high
over the desert SW holds on for another couple of days. One record
exceeded so far which was at Santa Maria (91 so far...previous
record was 88 in 2009). Temperatures have warmed quickly over
the inland central coast due to some offshore flow. Other observation sites
are approaching records...including San Luis Obispo and Camarillo.
Even though relative humidities are lower the heat indices are still
elevated through mostly the interior valleys. Temperatures will
essentially be similar tomorrow except for the central coast which
should cool a few degrees with a slightly stronger sea breeze.
Elsewhere of note are increasing north and northeast winds along
mainly the western portion of the sba South Coast and nearby Santa
Ynez. Isolated gusts around 40 miles per hour are expected tonight and little
stronger tomorrow night.
The upper level high shifts far enough east on Saturday while an
upper level trough moves into the West Coast to finally cool high
temperatures down...but will still be above normal over most of the
area. At least there shouldn't be any areas at or approaching
excessive heat conditions. Heights continue to fall on Sunday for
additional cooling to where some of area has highs below normal. And
for a change we should see some overnight coastal stratus along the
central coast and likely la County coast.
Long term (mon-thu)... long range models agree on keeping a fairly
deep trough over the West Coast over this period. Another cool down
Monday...then not much day to day change in high temperatures as
highs stay 5 to 10 degree below normal. The increasing onshore flow and
deeper marine layer will help spread the overnight and morning
stratus into the valleys.
At 2314z...the marine inversion at klax was around 450 feet deep. The
top of the inversion was around 2650 feet with a temperature of 30
Hi confidence in the 00z tafs with VFR conditions expected at all
the airfields through Friday afternoon. Gusty SW winds at kpmd and
kwjf during the late afternoon and early evenings will persist.
Klax...hi confidence in the 00z taf with VFR conditions expected at
the airfield through Friday evening.
Kbur...hi confidence in the 00z taf with VFR conditions expected at
the airfield through Friday afternoon.
Marine... 27/200 PM.
A Small Craft Advisory for moderate northwest winds across the
northern and central outer waters will continue through late
tonight... though winds will be below advisory criteria during the
early afternoon. There is a good chance that small craft advisories
will be needed this weekend for moderate winds.
Otherwise and elsewhere winds will be light to locally moderate.
Special Weather Statement (see laxspslox).
Small Craft Advisory (see laxmwwlox).
Moderate rip current risk (see laxsrflox).