Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
139 PM PDT sun Aug 2 2015
a weak trough of low pressure off the West Coast will maintain dry
southwest flow aloft across southwest California into next weekend
with weak onshore lower level flow. This will bring gusty west winds
to the mountains and deserts each late afternoon through late
evening. The marine layer and weak onshore flow will bring areas of
night and morning coastal low clouds and patchy fog extending into
the western valleys at times. High temperatures will warm to
above normal for middle week...then cool to a bit below normal for
late in the week and next weekend as a strong upper level low
pressure trough moves across California.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Coastal stratus is hanging tough early this afternoon along the
San Diego County coast and a few miles inland including much of
San Diego city proper...meanwhile all of coastal Orange County has
cleared out. Expect scattered to broken clouds to continue near
the San Diego beaches through late afternoon. Meanwhile well
inland locations are clear except for a decent cumulus field in
the San Bernardino and Riverside Mountains. Terrain driven mesoscale
boundaries noted on visible loop are helping to kick the cumulus field
but do not anticipate any showers in those locations at this time...but
will keep an eye on the cumulus field for any further development.
The large upper level subtropical high will be the dominant
synoptic feature for our region through the end of the work week.
The subtropical high will strengthen a bit and medium range models
are a bit stronger on the latest runs with the peak intensity
Wednesday-Thursday around 597 dm.
By late Thursday into Friday the models are in good agreement to
swing an unseasonably strong negatively tilted upper level trough
across California and into Saturday. This feature will bring a
dramatic cool down for next weekend...with inland locations likely
seeing a 10-20 degree temperature change over a few days time.
Precipitation chances look pretty slim at this moment although we may
need to add a mention over the higher mountains for
Thursday/Friday if any moisture tap can connect with the main
trough feature. Coastal stratus will likely surge well inland
during the late nights as well with a strong onshore flow for next
weekend. Strong onshore flow may persist beyond next weekend
keeping temperatures near to below normal levels across socal.
022030z...coast/valleys...bkn-ovc013-018 tops 020 returning to the
coastal airports between 01-03z...then moving 15-20 Michigan inland overnight
and lowering to ovc010-015 trough 12z. Areas of 3-5sm br. Skies
clearing back to the coastal airports Monday between 19-21z.
Mtns/deserts...mostly clear with unrestricted visible through Monday.
130 PM...northwest winds 15 to 20 knots over the outer waters Monday
through Wednesday with gusts from 20 to 25 knots. A Small Craft
Advisory may be needed then.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.