Scientific Forecaster Discussion
fxus66 ksgx 231025
Area forecast discussion
National Weather Service San Diego California
325 am PDT Sat Jun 23 2018
a low pressure system moving through the Great Basin will weaken
the high pressure aloft across Southern California and strengthen
the onshore flow spreading cooling inland through the weekend. It
will also deepen the marine layer with coastal low clouds
spreading farther into the valleys for tonight into Sunday
morning. High pressure aloft will bring warming for Monday
through Tuesday and Wednesday with the marine layer becoming
shallower. For Thursday into next weekend...a trough of low
pressure near the West Coast will strengthen the onshore flow
spreading cooling inland and deepening the marine layer for Friday
into next weekend.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
A low pressure system will move through the Great Basin into the
central rockies this weekend. This will weaken the high pressure
aloft across Southern California and strengthen the onshore flow.
This will spread cooling inland with high temperatures for inland
areas around 5 degrees cooler today than on Friday and with Sunday
high temperatures another 5 degrees cooler.
There is once again a weak coastal eddy with widespread coastal
stratus spreading into portions of the inland valleys. There will
be more deepening of the marine layer with the coastal low clouds
spreading farther into the inland valleys for tonight into Sunday
For Monday through Wednesday...high pressure aloft will move
across Southern California and the onshore flow will weaken a
little. This will bring a warming trend with the next round of
inland heat peaking Tuesday and Wednesday with high temperatures
around 5 degrees above average. The deeper marine layer will
continue into Monday morning...then become shallower for Tuesday
Another trough of low pressure will move to near the West Coast
on Thursday...then amplify into Southern California on Friday and
Saturday as it moves slowly into the western states. This will
bring stronger onshore spreading cooling inland with Friday high
temperatures for inland areas around 5 degrees below average and
high temperatures for Saturday a few degrees cooler than Friday.
The marine layer will deepen with coastal low clouds spreading
farther into the valleys for Friday and Saturday.
230920z...coast/valleys...stratus with bases ranging from 700-1500
ft mean sea level and tops to 2000 ft mean sea level continuing to spread 30-35 mi inland
this morning. Areas of vis 3-5 sm in br/haze in the valleys. Stratus
and vis restrictions clearing inland 15-17z and along the coastal
areas 17-19z. Beaches and up to a few miles inland may remain broken-
overcast through much of the afternoon. Stratus beginning to move back
inland after 24/01z and pushing into the inland valleys overnight.
Bases will be near 1100-1700 ft mean sea level.
Mountains/deserts...mostly clear with unrestricted visible through
no hazardous marine weather is expected through Wednesday.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.