Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
902 PM PDT Sat Aug 1 2015
a low pressure trough off the West Coast will force monsoon moisture
eastward over Arizona through the middle of next week. The trough
will also keep temperatures near their seasonal averages for early
August. The marine layer will be deep enough for low clouds to reach
the western valleys each night and retreat to near the coast each
afternoon. Gusty west winds will surface in the mountains and
deserts each afternoon.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Marine stratus decks are beginning to spread across the coastal
strip of San Diego and Orange counties this evening. The 00z
sounding from Miramar indicated a marine inversion of about 8
degrees celsius and the inversion strength hasn't changed much from
the past 24 hours. Meanwhile a few patches of high clouds are noted
across the inland mountains and deserts. Not much change in the
pattern is expected through this weekend so expect the generally
seasonal conditions to continue for most areas. Temperatures are on
track this evening so no non-routine changes were needed to the
ongoing forecast this evening.
..previous discussion (issued at 145 PM pdt)...
On Tuesday and Wednesday a 500 mb upper high briefly gains footing
over The Four Corners. This will bring warm/hot days to the
mountains and deserts. The marine layer will be a few hundred feet
shallower west of the mountains.
Long range outlook Thursday through Sunday...the 12z European model (ecmwf) and GFS
are in fairly good agreement with an unseasonably deep trough
setting up off the central California late next week. This trough
will bring cooler weather...a deeper marine layer and gusty mountain
and desert winds late next week through the weekend.
020300z...coast/valleys...low clouds will push inland and impact
coastal taf sites between 04z and 08z...with bases between 1400 and
1800 feet mean sea level and tops near 2100 feet mean sea level. The uncertainty with the kont
taf is high tonight...though a period of broken ceilings and reduced visible is
possible between 12z and 17z. Slow clearing is likely again for
Sunday...especially along the San Diego County coast. Confidence is
low to moderate that low clouds will clear to the coast by 19z.
Light to moderate sea breezes will prevail Sunday afternoon...with a
return of low clouds to the coast after 03z Tuesday.
Mtns/deserts...sct-bkn clouds at or above 25000 feet mean sea level and unrestricted visible
through sun evening.
800 PM...breezy northwest winds with gusts to 20 knots will be
possible over the outer waters each afternoon and evening through
Thursday. Otherwise no hazardous marine conditions are expected
through Thursday evening.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.