Area Forecast Discussion
Issued by NWS San Diego, CA
FXUS66 KSGX 262145
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
245 PM PDT THU MAY 26 2016
A weak trough of low pressure will persist over Southern
California through the holiday weekend. This will continue rather
cool conditions, but with some warming away from the coast. High
pressure building next week promises further warming across inland
areas, especially in the deserts. Nighttime and morning low
cloudiness will continue along the coast and inland valleys, but
with lesser inland extent in time through next week.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
The closed upper level low which was over Southern California
yesterday has pushed out into the Four Corners region, igniting
some severe thunderstorms ahead of it across eastern Colorado. As
this low continues to push away, another trough is digging in from
the Pacific Northwest. This trough will move in across the local
area this weekend with little discernable weather changes though.
The trough will be an inside slider, meaning the most prominent
area of lift should remain just to our east this weekend along
with little appreciable moisture. If any showers were to occur,
they would be spotty over the mountains/upper deserts, but there
is too much uncertainty with this so have left it dry for the
holiday weekend. A dry main message is good give this pattern.
A ridge builds across the Pacific off California early next
week and moves over the state by mid week. This will lead to a
shallower marine layer with nighttime/morning marine stratus
clouds having less extent inland. Dry weather will continue. Temps
across the Coachella Valley could reach near 100F then, which is
more typical for this time of year, compared to the well below
average temps felt there the past few days. Near the coast,
little change in temps will occur due to the marine influence of
the cool Pacific ocean waters where local sea surface temps are
running in the lower 60s.
Should mention that patchy drizzle was seen across San Diego
County this morning. Some hi res models do show light rain
amounts near the San Diego coast (0.01") towards dawn on Friday.
Have added patchy drizzle to coastal San Diego County and portions
of the inland valleys for the overnight and into Friday morning
to account for this possibility. /Gregoria
261950Z...Coast/Valleys...Sct clouds based around 3000 ft MSL
with tops around 4000 feet MSL coastal strip but cloudier about 5-20
miles inland with locally bkn clouds there. Low clouds will increase
after 02z this evening with bases down to 1500-2500 feet MSL with
tops down to around 3000 feet MSL and extending about 20 miles
inland. Risk of low cloud bases tonight down to around 1500 feet MSL
is moderate-high. Confidence in the timing of the solid low cloud
deck returning to the coastal airfields tonight is moderate.
Mountains/Deserts...Mountain locally obscured desert slopes
with clouds based around 5000 feet MSL and tops around 8000
feet MSL during the evening. West winds with gusts to 40 knots at
times will produce weak to moderate up/down
drafts over and east of the mountains through this evening.
1250 PM...Wind gusts near 20 knots this afternoon and evening over
the outer waters, otherwise, no hazardous marine conditions are
expected through Sunday.
Skywarn activation is not needed.