Scientific Forecaster Discussion
fxus66 ksgx 281508
Area forecast discussion
National Weather Service San Diego California
808 am PDT sun may 28 2017
weak high pressure aloft will bring warmer weather inland through
Tuesday, while the marine layer keeps the coast seasonal with areas
of night and morning low clouds and patchy fog. Cooler, with a
deeper marine layer and more extensive marine clouds for the latter
half of the week as a low pressure trough develops over the West
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Patchy low clouds were observed this morning along the coast and
inland up to 15 miles, otherwise the sky was clear across socal.
Marine clouds were extensive west of the islands. The Miramar
sounding had a 6 degree c inversion based near 1350 feet with light
and variable winds below 15k feet. Warming of 12 degrees c was noted
at about 4000 feet mean sea level. This should correspond to sharp warming on the
slopes of the mountains of San Diego and Riverside counties today,
including Julian and Anza.
Very little change is forecast to the synoptic pattern through Mon,
except for perhaps a weaker offshore sfc gradient from the NE. This
could result in better coastal marine stratus coverage Mon/Tue
mornings, especially given that it is climatologically favored, but
no guarantees. Warmer days inland through Monday, then a bit cooler
into midweek. No changes to the previous forecast.
From previous forecast...
Short term (today through tuesday)...
high pressure aloft will bring slow warming for inland areas into
Memorial Day with high temperatures near average today...and a
little above average on Monday. The marine layer and weak onshore
flow will keep coastal high temperatures near average.
For Tuesday...inland areas will cool to near average high
temperatures and the marine layer will deepen slightly as a very
weak low pressure system moves into Southern California and northern
Long term (wednesday through saturday)...
a trough of low pressure moving inland along the West Coast into
Southern California on Wednesday will bring cooling with inland high
temperatures 5 to 10 degrees below average...more clouds...and
deepening of the marine layer into the far inland valleys. Slow
warming for Thursday into Friday under weak high pressure aloft.
Another weak trough of low pressure near the Southern California
coast may bring slight cooling for next weekend.
281430z...coast/valleys...patchy low clouds with bases near 1500 ft
msl will continue over the coastal waters and along the coast
through 19z, otherwise sky clear and unrestricted visibility through 03z
Monday. Low clouds with bases near 1,000 ft msl should filter back
along the coast after 03z. Ceilings are expected at ksan, kcrq and
ksna between 06z and 16z Monday. Low clouds will dissipate after 16z
Monday, leaving sky clear and light winds for Monday afternoon.
Mountains/deserts...skc-few at or above 20,000 ft msl, unrestricted
visibility, and light winds through 00z Tuesday.
quiet conditions are anticipated through Friday with a mixed swell
(2-4 ft at 6-9 sec from the northwest and 2 ft at 12-15 sec from the
south). Winds will remain light out of the northwest this week, with
the typical afternoon/evening peak in wind speeds. Strongest winds
will be found in the vicinity of San Clemente Island.
Skywarn activation is not requested.