Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
925 am PDT sun Apr 26 2015
A ridge of high pressure moving into California from the west and a
surface high building over Nevada and Utah will bring a drying
northeast wind and a warming trend to Southern California Monday and
continued warm through Tuesday. By Wednesday the night and morning
marine layer low clouds and fog will return...with cooling most
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Short term (today through tuesday)...
A shift in the pattern is developing over the region...after an
extended period dominated by a trough. We expect upper level high
pressure to build over the region...and push the storms to the
north...while allowing Southern California to heat up a bit. Some
pesky clouds around today...but northerly flow will push that out by
this afternoon for mainly clear and warming conditions into Tuesday.
The local WRF and BUFKIT data show a strong drying trend. The winds
should be the biggest issue...targeting the period from late tonight
into midday Monday.
Long term (wednesday through saturday)...
By Wednesday...as we look at the ensembles...there is beginning to
be some differences in the the ensemble members at that time...and
possibly a trend toward a slightly faster trough. This should cause
heights to lower on Wednesday...and the accompanying falling of the
surface pressures over the west should pull in the onshore flow and
some associated...mainly night and morning coastal low clouds and
fog. Generally...cooling will spread inland from the coast during
the latter half of the week and continue into the weekend.
Aviation... 261530z...coast/valleys...patches of low clouds with
bases 2000-3000 feet mean sea level lingering this morning...mainly along the
coastal mountain foothills. Otherwise...generally VFR with
unrestricted visible for the rest of today and tonight.
Mts/deserts...coastal slopes locally obscured in clouds through
15z...otherwise mostly clear with unrestricted visible for today and
tonight. Northerly and gusty winds to around 25kt over the ridges
and along desert slopes through about 18z with associated moderate uddfs
and local low level wind shear. The winds will drop off later in the day...then
increase from the NE and become strong and gusty through and below
passes and canyons near the coastal foothills tonight through Monday
morning...with local gusts over 50 kts possible.
830 am PDT...northwest winds have dropped off significantly this
morning down to around 20 knots at the San Clemente buoy. Combined sea
heights are also on the decline at this time. The Small Craft
Advisory will remain in effect as wind gusts are still expected to
qualify marginally with gusts of 20-25 knots...continuing rough seas
through this afternoon. Seas and winds will continue to slowly
subside today through Monday. &&
High pressure surface and aloft will bring a warming trend through
Tuesday. Surface high pressure building over the Great Basin will
bring a period of locally strong gusty northeast winds from before
sunrise early Monday morning until around noon on Monday below the
Cajon Pass and near the coastal foothills. The winds combined with
decreasing humidities could bring a few hours of near critical fire
weather conditions Monday morning.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
California...Wind Advisory from 4 am to noon PDT Monday for Orange County
inland areas-San Bernardino County mountains-San Bernardino
and Riverside County valleys-the inland Empire-Santa Ana
Mountains and foothills.
Pz...Small Craft Advisory until 10 PM PDT this evening for waters
from San Mateo Point to the Mexican border extending 30 to
60 nm out including San Clemente Island.