Scientific Forecaster Discussion
Southwest California area forecast discussion...corrected
National Weather Service Los Angeles/Oxnard California
247 am PST Thursday Mar 5 2015
High pressure will build in over the region through the weekend
bringing warmer temperatures and mostly clear skies into early
next week. There is a slight chance of more rain beginning next
Short term (today-sunday)...
Mostly clear skies continue over the area this morning as an
upper-level ridge of high pressure near 35n and 132w builds in
over the region. Offshore flow in place at the surface and high
pressure aloft will bring a warming trend through the weekend.
Daytime temperatures will be well above seasonal normals through
weekend...with at least middle 70s to middle 80s prevalent for the
coasts and valleys. The warmest days appear to be Friday and
Saturday when the ridge center is overhead. There is a chance that
forecast temperatures could be too cool for Friday and Saturday as
MOS guidance takes a rather warm stance. Local temperature studies
stray from MOS guidance...and thus the package trends the way of
the local studies for the package.
A slight dip in the temperatures remains in the package for
Sunday...but all models point to 500 mb heights continuing to
climb. This could bring an even warmer day for Sunday if the model
solutions play out...but with the ridge axis east of the area...it
is difficult to argue in favor of additional warming.
Long term (monday-thursday)...
Ridging aloft reenforces for early next week and the ridge center
builds again over the region between Monday and Tuesday. This
could bring another brief warmup to start the work week.
Temperatures have warmed for early next week with Tuesday likely
being the warmest day in the stretch when the ridge center is once
A cooling trend should takes shape for middle-to-late week as a broad
trough of low pressure approaches the West Coast. Run-to-run
consistency and timing issues continue to plague the
GFS...Gem...and European model (ecmwf) solutions. Despite lower confidence on the
exact timing of the system...confidence is growing for at least a
cool...cloudy and unsettled weather pattern sometime between
Wednesday and Friday next week. Both GFS and European model (ecmwf) solutions
increase 850 mb mixing ratios to near 8 g/kg over the area between
Wednesday night and Thursday night...or almost 3 Standard
deviations above the mean for naefs solutions. Slight chances probability of precipitation
and cloudy skies have blanketed the extended period for the
At 1000z...there was no marine inversion at klax.
Overall...high confidence in 12z taf package as weak offshore flow
should keep all sites at VFR levels...but there will be a 20% chance
of LIFR/vlifr conds at kprb 12z-17z this morning. With the offshore
flow...there is the chance of some light-MDT turbulence/low level wind shear south of
Point Conception 12z-22z today.
Klax...high confidence in 12z taf. VFR conds will prevail through the
Kbur...high confidence in 12z taf. VFR conds will prevail through the
period. There is a 20% chance of MDT turbulence/low level wind shear 12z-20z today.
For the outer waters...high confidence in northwest to north winds
remaining below Small Craft Advisory thresholds through Friday. For
Saturday through Monday...the northwest winds will increase with a
good chance of Small Craft Advisory-level winds developing.
For the inner waters...high confidence in winds remaining below
Small Craft Advisory thresholds through Monday. For today and
Friday...there may be some local northeast wind gusts reaching
Small Craft Advisory thresholds in the morning to early afternoon
hours near shore.
high rip current risk (see laxmwwlox).