Scientific Forecaster Discussion
Southwest California area forecast discussion
National Weather Service Los Angeles/Oxnard California
333 am PST sun Feb 1 2015
high pressure aloft will result in dry weather and slightly above
normal temperatures for much of this week. A frontal system may
bring some light rain to the central coast Friday into Saturday.
Short term (today-tue)...clear skies across the region this
morning. Some patchy low clouds/fog may develop or push into
interior sections of slo County. Otherwise...expect mostly sunny
skies today...with just some scattered high clouds from time to
time. Low level gradients were weakly offshore...and there were some
gusty winds in the mountains of l.A. And vtu counties. Some gusty winds
could push into the valleys of l.A. And vtu counties this morning...but
winds will remain well below advisory levels. Maximum temperatures today should
be up a couple of degrees in most areas...generally several degrees
above normal for the first day of February.
The positively tilted upper ridge building into central California today
will become more neutrally tilted Monday and Tuesday...with the ridge axis
moving across the region on Tuesday. Some low clouds may develop across
coastal sections of l.A. County tonight/Monday morning...with a better
chance of night through morning low clouds/fog in coastal sections
of l.A. County...portions of the central coast...and possibly the
San Gabriel valley Monday night/Tue. Heights/thicknesses change rather
little through Tuesday...but offshore gradients do turn onshore...and
increase...especially on Tuesday. Overall...expect mostly minor changes
in maximum temperatures Monday and Tuesday from those observed today...although there
will probably be at least a couple of degrees of cooling on the
coastal plain and in the Lower Valley locations.
Long term (wed-sat)...the upper high will actually amplify a bit
over the region Wednesday and Thursday as a broad trough moves into the eastern
Pacific. Expect a fair amount of high clouds...and any night through
morning stratus will likely remain confined to the coastal
plain...and possibly Lower Valley locations such as the Santa Ynez
Valley and the San Gabriel valley. Maximum temperatures will probably edge
upward a couple of degrees...especially away from the coast.
A frontal system will move into northern California on Friday...and while most
of its moisture will likely remain north of the region...there is a
slight chance of light rain or showers Friday afternoon through early
Sat north of pt Conception. Otherwise...there should be a fair amount of
high cloudiness. Heights will actually rise...especially across southern
sections of the forecast area...so there could be a bit of warming...but
there will probably be enough thick high clouds to temper and
warming. The upper ridge will amplify again Sat...forcing any
moisture well to the north of the region...and likely bringing a few
degrees of warming to most areas.
At 920z there was no marine layer at klax but there was a surface based
inversion with a top of 1000 feet and a temperature of 18 degrees
Good confidence in ceiling and visibility unlimited tafs. There is a 30 percent chance of some
marine layer clouds late tonight.
Klax...good confidence in 12z taf there is 30 percent chance of MVFR
ceilings after 10z.
Kbur...very high confidence in the 12z ceiling and visibility unlimited taf.
Weak offshore trends will persist through this morning.
Otherwise...light winds will affect the outer waters. A large nearly
stationary low pressure system south of the Aleutian Islands. Swells
generated by this storm will move into the coastal waters Monday
night into Tuesday...but are expected to remain below the threshold
for Small Craft Advisory for hazardous seas.