Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
140 PM PDT Sat may 30 2015
Synopsis...high pressure aloft has peaked over the region today...
and will move east early next week as low pressure redevelops over
the west. Low clouds and patchy fog will redevelop tonight and
spread ptogressively farther inland through Wednesday as onshore
flow and the marine layer increase. Westerly winds will become
gusty over the mountains and deserts again by late Monday...helping
to cool inland areas. Little change is expected over coastal
areas...except for only partial clearing some days. Daytime
temperatures will become progressively cooler through next week.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Marine stratus was extensive over the California coastal waters early this
afternoon...and covered coastal areas of San Diego countyas well
through 1 PM PDT. Winds were light at most reporting sites except
for the windier desert slopes where gusts over 25 miles per hour were reported.
Due to late clearing...at 1 PM PDT...temperatures were a few degrees shy of
values observed yesterday along the coast...but were 3-5 degrees f
higher across the inland Empire.
Marine stratus and areas of fog will spread inland again this
evening and should become entrenched over coastal and western valley
areas through Sun morning. This favors cloudy skies for the runners
in the big Marathon Sunday morning. Temperatures will be in the 60s. At
this time...clearing looks limited in the afternoon as well.
Slightly cooler inland tomorrow...otherwise fair and warm.
The latest 12z model run solutions are close through the middle
of next week with the timing and intensity of the wave train coming
off the eastpac and moving through the west. There is considerable
difference in the upper-level pattern by the latter half of the
week though. The European model (ecmwf) continues to be deeper with the developing
trough then...while the GFS has been in catch-up Mode. Both now show
a closed low near socal by Friday. This is a similar pattern to what we
have seen much of this month. The European model (ecmwf) holds the trough over socal
through next weekend...while the GFS wants to recover heights and
weaken it. Given trends and model continuity...it would appear
the European model (ecmwf) solution is favored.
In terms of sensible weather highlights over socal...look for a slow
cooling trend...beginning on sun...and continuing through the week
with a deepening marine layer and more and widespread coastal
stratus nights and mornings. Looks like a typical June pattern
with some marine clouds lingering into the afternoons some days.
This will keep daytime highs below average Wednesday through the end of
the week. Also...look for some gusty westerly winds over the
mts/deserts beginning Monday.
No significant precipitation is likely through this period...however the
deeper marine layer may leak drizzle at times...particularly during
the latter half of the week. There will also be the benefit of less
evapotranspiration due to added cloud cover...lower temperatures...and
higher relative humidity. Given the forecast pattern...some light
accumulations of precipitation are not out of the question either
after Wednesday...along and west of the mts...similar to conditions
earlier this week.
302030z...patches of low clouds...with bases from 1000 to 1400 feet
mean sea level and tops near 1700 feet mean sea level remain at the beaches this afternoon.
Low clouds will likely begin spreading inland after 03z sun with bases
between 1000 and 1500 feet and tops to 2000 feet. Low clouds and fog
could reach the inland valleys by 10z sun. Kont may be impacted after
10z...but confidence is not high.
Otherwise...few/sct high clouds with unrestricted visible through
130 PM...no hazardous marine weather is expected through Wednesday.
130 PM...some south swells of 4 feet/14 seconds are likely to be
generated from Hurricane Andres. This could bring some elevated surf
and stronger rip currents mainly to northern Orange County late
Monday and Tuesday.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.