Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
140 PM PDT Sat Oct 25 2014
a trough of low pressure will continue to move inland across the
West Coast this weekend...bringing cooler conditions and some middle
and height level clouds to Southern California at times as well as
some gusty west winds to the mountains and deserts. High pressure
will then rebuild over the west...with dry and warmer conditions
developing for the work week. Another trough may then move inland
across the West Coast for next weekend.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Water vapor imagery shows a trough of low pressure moving inland
across the West Coast this afternoon...with the upper level low
moving inland across the Washington coast and the associated cold
front extending southward across Oregon and northern California.
Although the cold front is still north of Point Conception at this
time...cooler conditions are prevailing across the Southland...with
temperatures are running 5 to 10 degrees cooler than this time
yesterday. The gradients are also now onshore...with some locally
gusty west winds developing through and below the favored passes and
canyons. At this point in time...the upper level support looks
marginal at best...only 30 knots...so think only the favored spots will
see gusts up to 45 miles per hour this afternoon and evening.
This trough will continue to move inland across the West Coast this
weekend...with even cooler conditions developing for Sunday. The
local models are showing the marine layer deepening to between 3000
and 3500 feet tonight...but it appears that it will be somewhat
disorganized. For this reason...think it will be hard for drizzle
to develop tonight...and have removed it from the forecast.
Otherwise...just expect the gusty west winds to continue across the
mountains and deserts again tomorrow.
As this trough shifts east...high pressure will slowly rebuild along
the West Coast for the first part of the work week. At this point
in time...think Monday will be similar to or only slightly warmer
than Sunday...as dry northwesterly flow continues to prevail.
However...high pressure will rebuild for Tuesday and
Wednesday...with dry and warmer conditions developing. There may
evening be some weak offshore winds across the inland areas these
days...with some locally gusty conditions possible in the favored
passes and canyons.
The extended models are still in agreement that another trough will
take aim at the West Coast for Friday and the weekend...which means
there was at least some run to run consistency with the last two
runs. However...there is now some disagreement on whether or not
this trough will dig deep enough that Southern California could get
some light showers. For this reason...will keep the forecast dry
for now...and continue to monitor these trends until confidence is
high enough one way or another. However...have started to trend the
forecast cooler once again...and reintroduced the marine layer for
Friday and Saturday.
252028z...coast/valleys...sct clouds at or above fl100...with isolated
patches of lower clouds around 1500 feet mean sea level along the coast and
unrestricted visible through 04z. After 04z through 08z widespread broken-overcast
ceilings developing 1500-2000 feet mean sea level...with tops from 2000-2500 feet mean sea level
spreading inland 25-30sm...with areas of 3-5sm visible in br/haze and
locally lower inland where the stratus deck intersects and obscures
higher terrain. The stratus layer expected to burn off 16z-18z Sun
morning. Low to moderate confidence for ceiling arrival and moderate
confidence for ceiling heights at individual taf sites.
Mountains/deserts...areas of scattered clouds at or above fl100 with unrestricted
visible through sun.
100 PM...no hazardous marine weather conditions are expected through
100 PM...a northwest swell...peaking at about 9 feet in the outer waters with
a 14 second period...combined with a 2 feet south swell at 17 seconds
will create above normal surf of 3-6 feet...with local sets of
around 8 feet along exposed west-northwest facing beaches on Sunday.
Highest sets will be near Huntington Beach and exposed west facing
beaches of southern San Diego County. A beach hazard statement for
elevated surf and a high risk of rip currents GOES into effect
Skywarn activation will not be needed today.
California...beach hazards statement from Sunday morning through Sunday
evening for the Orange County coastal areas...San Diego
County coastal areas.