*Annual Rainfall is based on the California Water Year,|
which runs from October 1 through September 30.
FXUS66 KSGX 052019
Area Forecast Discussion
National Weather Service San Diego CA
119 PM PDT Tue Jul 5 2022
The upper trough over the Eastern Pacific will continue to weaken
through the weekend while high pressure over the Central US
strengthens and expands westward. This will support a gradual
warming trend through the weekend, with high temperatures Saturday
through Monday topping out up to 5 degrees above average for many
inland areas. Areas near and along the immediate coast will remain
relatively cool during much of this period due to marine layer low
clouds each morning. Cloud coverage will spread into the valleys
each morning through Thursday, after which the marine layer will
become shallower and mostly confined to coastal areas.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
The upper level high over the Central US will begin to strengthen
and expand westward this week while an upper level cutoff low and
attendant trough near the BC/WA coasts remains in place. This
will favor a gradual warming trend through the week ahead while
onshore flow persists at the coast, keeping temperatures
relatively cool. High temperatures each day will warm up by a
degree or two for most inland areas. The coast, on the other hand,
will see highs remain relatively steady as the persistent onshore
flow and marine layer clouds each morning inhibit daytime
heating. The marine layer will become more and more shallow
through Thursday as the Central US high expands westward over the
Four Corners region. By Friday, marine layer clouds and fog will
be mainly confined to coastal areas.
The warmest temperatures of the period look to occur Saturday
through Monday as the upper high over the Four Corners region
peaks in strength around 597dm. The immediate coast and coastal
valleys will see their warmest day on Saturday, while the deserts
and Inland Empire see highs peak on Sunday and remain fairly
similar on Monday, perhaps a degree or two cooler in spots. Highs
will top out up to 5 degrees above seasonal average for many
inland areas this weekend. This translates to the middle and upper
70s along the coast and the middle to upper 80s in the coastal
valleys on Saturday, the middle and upper 90s in the Inland Empire
on Sunday, between 99-102 degrees in the high deserts Sunday and
Monday, and around 110-113 for the lower deserts and the Coachella
Valley on Sunday and Monday.
Dry weather is expected to continue through early next week with
any monsoonal moisture fluxes remaining well off to our east. The
more likely chances for more substantial moisture return will be
during the middle portions of next week as the upper high over the
Four Corners retrogrades back a bit westward. This may allow for
some middle and upper level moisture plumes to wrap around the
southern periphery of the high and into portions of Southern
California. EPS/GEFS guidance continue to carry some precipitation
chances heading into the middle portions of next week, which will
be closely monitored. PoPs below 10 percent will be maintained
given the inherent uncertainty with timing and placement of any
potential rain chances.
052000Z...Coast/Valleys...SKC-SCT020 through 02Z. After 02Z BKN-
OVC015-025 returning coastal areas and spreading 20 miles through
14z Wed. Skies clearing back to the coast through 18Z Wed.
Mountains/Deserts...Mostly clear with unrestricted vis through Wed.
WNW winds 25-35 kt over/east of mtns and deserts 06/00-07Z with
areas of moderate up/downdrafts east of the mountains.
A Small Craft Advisory is in effect for the Outer Waters through
midnight tonight for northwest winds gusting to 25 knots near San
Clemente Island and steep, short-period wind waves. Winds weaken
tonight, then strengthen again Wednesday afternoon with gusts to
around 20 kt. No hazardous marine weather Thursday through Saturday.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
PZ...Small Craft Advisory until midnight PDT tonight for Waters from
San Mateo point to the Mexican Border Extending 30 to 60 nm
out including San Clemente Island.