Scientific Forecaster Discussion
fxus66 ksgx 200503 aaa
Area forecast discussion
National Weather Service San Diego California
1000 PM PDT Fri Jul 19 2019
weak low pressure continuing off the West Coast remains the dominant
weather feature as the monsoonal high pressure in the interior
remains well east of Southern California. This has kept temperatures
moderated and the trough has also kept the mountains and deserts
dry. Little change and seasonable conditions are expected to prevail
over the next couple of days as weak low pressure off the West Coast
continues the onshore flow into Southern California. A general
warming trend should develop by Monday as high pressure near The
Four Corners area pushes westward. Thunderstorms will be possible
beginning about Monday. There could even be some sprinkles drifting
over much of the area at times into Wednesday. The low clouds and
fog nights and mornings near the coast should decrease some into
Wednesday, increase a bit through about Friday, before becoming more
shallow again by next weekend.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Evening update: no changes were needed this evening.
Previous forecast discussion, issued at 113 PM pdt:
Not much difference from normal today with the onshore flow
associated with the trough keeping the weather moderated, even in
the mountains and deserts. Just a few high clouds at times for the
next couple of days, with of course the usual night and morning low
clouds and fog. Some breezy conditions mountains and deserts.
Monsoonal conditions will be on tap for the first half of the coming
week as the high pushes west toward US. Thunderstorms could begin as
early as Monday afternoon, and there is an outside chance that some
sprinkles could survive the trip to the coastline at time during the
first half of the week. We will keep an eye on the ensemble models
along with the deterministic models to see what solutions look more
probable. The possibility of thunderstorms will probably fall a bit
as the high moves over US the end of next week, but may be quite
warm by then.
200230z...coast/valleys...low clouds inching their way at the coast
will slowly start to spread and progress eastward. Ceilings with bases
1000-1500 ft mean sea level will extend 20-25 mi inland. Moderate confidence in
period of ceilings at kont/ksbd after 10z. Local visible may fall to 3-5sm
in br/haze in some valleys and on elevated coastal terrain. Low clouds
expected to scatter out around 16z inland and 17-18z at the Coast.
Mountains/deserts...northwest surface winds gusting 20-25 kts through passes
into lower deserts until 06z tonight. Otherwise, clear with
unrestricted visible through Saturday.
no hazardous marine weather expected through Wednesday.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.