Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
330 am PST Sat Dec 21 2013
a cool...dry...northerly flow is expected to continue over Southern
California today...then a slow warming trend is expected
Sunday into Monday as high pressure develops over the plateau. Some
morning low clouds are expected this morning...with less Sunday
morning...otherwise mostly clear skies will prevail much of the
coming week. Daytime temperatures should be above normal most areas
beginning Sunday. Winter officially begins at 9:11 am PST this
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Low clouds continue in some areas west of the mountains as a cool
westerly flow continues over the region. There should be an increase
in the low clouds as the night wears on...mainly south and east of
Orange County. This is indicated on the local WRF as well as the
BUFKIT data. I added some patchy fog to the Oceanside area...likely
due to cold air drainage into the area and left over residual
moisture from the recent rains.
The models indicate high pressure beginning to develop over the
plateau by Sunday for a bit of warming most areas. Still some
patches of low clouds could be around Sunday morning. This is seen
in the BUFKIT soundings and the low level model data relative
On Monday afternoon the deterministic European model (ecmwf) is almost identical to
the European model (ecmwf) ensemble run in the upper levels. At the surface both show
high pressure building into the plateau. The surface high pressure
should be enough to allow the low clouds and low level moisture to
be pushed out to sea somewhat on Sunday...and completely offshore on
Monday. Along with drying conditions...additional warming and
generally clear skies can be expected. Warmer still Tuesday.
By Wednesday afternoon high temperatures over the coastal and valley
areas should be about 10 degrees or more above normal as surface
high pressure strengthens over the plateau. The European model (ecmwf) is stronger on
the surface high than the GFS. The upper level ridge of high
pressure inches toward the coast as well. This should result in
widespread middle to upper 70s for the warmer areas west of the
Little change from Thursday into Saturday as the upper high
continues over the coastal states...with the precession of surface
highs continuing over the plateau. This should continue the well
above normal temperatures in the coastal and valley areas into the
weekend...if this model pattern verifies.
211115z...coast/valleys...areas of stratus will continue through
17z...mostly in the valleys...with bases 2000-2500 feet mean sea level and tops
to 3000 feet mean sea level. This will briefly affect ksan/kcrq. Some valley fog
will occur with visible locally less than 1 mile through 17z. After 17z
and through tonight...mostly VFR conditions will prevail with only
scattered clouds at 2500 mean sea level and mostly unrestricted visible.
Mtns/deserts...mostly clear skies with unrestricted visible will occur
again today through tonight.
a long-period northwest swell arriving on Sunday will bring a high risk of
rip currents along the beaches through at least the middle of next
week. The swell will be 4-6 feet at 18-20 seconds in the outer
waters...but with a northerly enough direction so that most beaches
will only have 4-6 feet surf mainly Sun night/Mon.
Skywarn activation is not requested. However weather spotters are
encouraged to report rain and snow totals to their local National
Weather Service office.