Scientific Forecaster Discussion
fxus66 klox 180410 aaa
Area forecast discussion...updated
National Weather Service Los Angeles/Oxnard California
910 PM PDT Wed Jul 17 2019
Night through morning low clouds will continue cover the coast
and valleys throughout the week with a cooling trend through
Saturday. A Four Corners high pressure system will expand westward
into the region on Sunday and last through next week bringing
another spell of summertime heat.
Short term (tnt-sat)...17/908 PM.
The latest satellite imagery shows stratus becoming entrenched
across the area with clouds filling in along the central coast
and the Los Angeles County coast. Onshore flow beneath weak
troughing aloft should permit clouds to become more expansive
overnight and into Thursday morning. The marine layer depth is
currently near 1800 feet deep from the latest amdar soundings at
klax, which agrees well with NAM bufr time height sections and
is quite close to radiosonde observation soundings from kvbg earlier this evening.
If NAM bufr time height sections play out, the marine layer should
deepen to around 2500 feet deep. The latest update expands the
marine layer induced stratus into the Santa Clarita valley and
brings in stratus a bit earlier into the Salinas valley portion of
San Luis Obispo County.
Onshore flow will continue to strengthen into Thursday. Current
surface pressure gradient trends are trending about a millibar or
two stronger this evening than last evening. The latest model
solutions support this idea and a general cooling trend should
linger into Thursday.
***From previous discussion***
Not much difference Fri/Sat either. If anything maybe a degree or
two cooler Friday and a little warmer Saturday but overall very
Long term (sun-wed)...17/142 PM.
High pressure from the southeast still expected to expand west
over California beginning Sunday. The upper high is expected to be
centered near the 4 corners by Tuesday while at the same time
onshore gradients will be trending weaker. Therefore the forecast
for warming through the period still looks good and it's just a
matter of how warm. There's the potential for temperatures to
reach The Levels we saw this last weekend. And on top of that we
might also be seeing an increase in monsoon moisture by Wednesday,
especially la County.
At 2230z, the marine layer depth was around 2100 feet deep at klax.
The top of the inversion was was near 3100 feet with a
temperature around 23 degrees celsius.
IFR to MVFR conditions will spread into coastal and valley
terminals through 10z. There is a chance of LIFR conditions north
of Point Conception between 08z and 14z. VFR conditions should
develop later on Thursday. There is a chance of MVFR conditions
lingering at coastal terminals through much of the day.
Klax...MVFR conditions will spread into klax between 04z and 08z,
then linger through at least 17z. There is a 30 percent chance of
MVFR conditions lingering until as late as 22z.
Kbur...there is a 40 percent chance of IFR conditions at kbur
between 07z and 11z. VFR conditions should develop between 16z
For the outer waters... local Small Craft Advisory (sca) gusts
will affect the waters near Point Conception through late this
evening. After that the winds will remain below Small Craft Advisory levels through
the period, although near-Small Craft Advisory conditions (10 to 20 kt) are
expected Friday and Saturday nights.
For the all of the inner waters, conditions will remain below
advisory levels through Monday.
Hazard potential outlook (sat-wed).
No significant hazards expected.