Scientific Forecaster Discussion
Southwest California area forecast discussion
National Weather Service Los Angeles/Oxnard California
345 am PDT Tuesday Aug 4 2015
..updated aviation discussion...
Weak high pressure building over the southwest will bring a slight
warm up for midweek...then a dry trough of low pressure off the
coast will push east through the area late in the week for a cooling
trend. Temperatures will remain mainly below normal with overnight
to morning coastal clouds and fog persisting into the weekend.
Short term (today-thu)...800 foot marine layer capped by a very
weak inversion is generating little in the way of low clouds and
except for the central coast do not think any will develop. Mostly
sunny or at worst partly cloudy skies as some cirrus drifts
overhead. The lack of a strong inversion will allow for a little
coastal warming but the inland temperatures will be similar to Monday. Northwest
push across the SW portion of sba County is strong enough for
advisory level canyon gusts through dawn. Condition are similar for
another sundowner Wind Advisory this evening and overnight for southern
sba County...again strongest in the Gaviota area.
A little pop up ridge moves into the area ahead of a dry cut off
low. There will again be a minimal marine layer. Onshore flow
relaxes and maximum temperatures will jump a 3 to 6 degrees making Wednesday
the warmest day of the week.
A little transition day on Thursday as the weak ridge leaves and the
weak upper low approaches. Still not much in the way of low clouds
in the morning. Heights will fall through the day and this will knock a
few degrees off of the temperatures.
Long term (fri-mon)... the upper low moves into Monterey County
Friday Thursday Saturday. It looks quite dry and almost all of the
dynamics stay north of the area. It will most likely only bring
partly cloudy skies to slo County but have to watch it as any upper
low can bring a few surprises. What is much more likely is the
gentle lift from the trough and the lowering heights will allow a deep
marine layer cloud pattern to form and each morning Friday and Sat low
clouds will cover the coasts and most of the valleys. Maximum temperatures will
slide downward across all areas with the biggest drops in the
previously clear valleys.
The upper low leaves and is replaced by dry SW flow between a Texas
high and a Gulf of Alaska low. Weather will be pretty dull. There
will likely be night through morning low clouds across the coasts
and lower coastal valleys. Maximum temperatures will climb a few degrees each day
as heights rebound but will still be a few degrees below normal.
At klax at 1030z there was a 800 foot deep marine layer with a
moderately strong inversion top at 2800 feet with a temperature of 26
Moderate to high confidence for valley and inland taf forecasts...fair
confidence in coastal tafs with a 20 percent chance of MVFR ceilings 12z-
Good confidence in VFR forecast for all tafs after 17z.
Klax...good confidence in 12z taf through 17z with a 30 percent chance of
bkn015. High confidence in VFR forecast 17z-08z. Fair confidence after 08z
Wednesday with a 20 percent chance of MVFR ceilings.
Kbur...high confidence in 12z taf.
Small Craft Advisory conditions for all outer waters with northwest
winds and very steep seas will persist from Point Conception to
south of San Nicolas Island through Wednesday morning. Small Craft Advisory
conditions will continue in the west half of the Santa Barbara
Channel this afternoon and evening as well as zone 645 from Point
Piedras Blancas to Point Sal.
Wind Advisory (see laxnpwlox).
Small Craft Advisory (see laxmwwlox).