Scientific Forecaster Discussion
fxus66 klox 301649
Area forecast discussion
National Weather Service Los Angeles/Oxnard California
949 am PDT sun Apr 30 2017
it will be sunny and warm today. A weak marine layer will develop
on Monday and will bring some cooling to the coastal areas. Mostly
clear skies and slightly above normal temperatures will continue
for the upcoming week.
High pressure and weak offshore flow have brought clear skies to
the area. There will be some weak morning canyon winds but nothing
of note. The coasts will cool some due to the early seabreeze and
the vlys likely be at least as warm as ydy or maybe a little
warmer due to a warmer airmass. The interior will for sure be
A weak eddy will bring some morning marine layer clouds to the la
coast but otherwise Monday will be a sunny day. The weak offshore
flow will turn onshore and this knock 3 to 6 degrees off of the
coastal temps and 2 to 4 degrees from The Vly temps. The upper
level ridge actually strengthens a touch and the interior will see
The NAM forecasts a weak burst of north winds on Tuesday morning
so there may be a few canyon breezes in the morning. No where near
strong enough to push the stratus away from the srn la County
coast so the lgb-lax area will likely have low clouds in the
morning. Coastal and Vly temps are forecast to be similar to
Monday although if the north winds are just a little stronger
there will be some warming in the vlys. Temperature guidance
suggests further interior warming but the ridging patter is
unchanged from Monday and really think temps will be quite
similar to monday's values.
00z ec and GFS have come into agreement for the long term forecast
with the GFS trending to the more interesting cooler wetter ec.
The ridge will persist over the state Wednesday and really do not
see much change in the weather from Tuesday.
The ridge will push eastward on Thursday and by afternoon the
state will be on the back side of it. But all in all it should
have too much of an effect on the weather. There will be some
morning marine layer clouds in the lax-lgb area but otherwise it
will be a sunny day. Max temps in the interior will be 5 to 10
degrees above normal while the coastal areas will see highs at or
a few degrees above normal.
An upper low begins to work its way down the West Coast on Friday.
Hgts will lower and the upper level flow will take on a cyclonic
bent. The marine layer clouds will expand and Max temps across the
vlys and the interiors will cool.
The upper low elongates and moves further south on Saturday. This
will create a large marine layer that will cover the coasts and
vlys. Max temps will drop to below normal for the first time in
more than a week
The upper low expands and moves into the area Saturday night and
Sunday. If this comes true there will be scattered shower activity
across the area. But this solution is still along ways away and
could well change with time.
At 1530z, there was a surface-based inversion at klax. The top of
the inversion was 1900 feet with a temperature of 20 degrees
Overall, moderate to high confidence in 18z taf package. High
confidence in VFR conditions for all sites through this evening.
For tonight, low confidence in return of IFR/LIFR conditions to
Klax...overall, moderate confidence in 18z taf. High confidence in
VFR conditions through tonight. For tonight, low confidence in
forecast return of stratus/fog as well as timing of return and
flight category. There is a 50% chance that conditions will
remain VFR tonight.
Kbur...high confidence in 18z taf as VFR conditions are
anticipated through the period.
For the outer waters, moderate confidence in current forecast.
Small Craft Advisory (sca) level winds are expected to develop
later today. The Small Craft Advisory level winds are expected to continue through
Tuesday evening with the strongest winds during the afternoon and
evening hours. For Wednesday and Thursday, winds and seas are
expected to remain below Small Craft Advisory levels.
For the inner waters, moderate confidence in current forecast. For
the waters north of Point Sal, winds are expected to remain below
Small Craft Advisory levels through Thursday (although there is a 20% chance of Small Craft Advisory
level winds each afternoon/evening through tuesday). For the
waters south of Point Conception, winds and seas are expected to
remain below Small Craft Advisory levels through Thursday.
Pz...Small Craft Advisory in effect until 9 am PDT Tuesday for
zones 670-673-676. (See laxmwwlox).
Hazard potential outlook...(tue-sat)
no significant hazards expected.