Area forecast discussion
National Weather Service San Diego California
200 PM PDT Wednesday may 22 2013
Synopsis...
upper level low pressure settling over the west will result in
extensive...mainly night and morning low clouds...continuing through
the weekend and into next week. Gusty mountain and desert winds can
be expected at times.
&&
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
counties...
May continues over the region...based on the calendar and based on
the weather. The marine layer has hung around quite a while today.
A strong eddy is in progress with sustained winds southerly at 10
knots at ksan. Strong onshore trends of 2 mb to the local deserts
and over 4 mb to Nevada should help ensure that the low clouds will
be back again tonight...and also deeper.
Looks like the cooling trend should spread to the inland areas and
continue to remain cool into the weekend. Many places should be
experiencing below normal temperatures...especially during the
afternoon.
A parade of shortwaves will be rotating around the main anchor low
over the west...so the timing of the responses of the marine layer
will be modulated by the timing of the shortwave producing the
response.
The WRF-ems basically has well formed eddy winds over the coastal
waters on a daily basis at least into Saturday. The GFS 500 mb
ensemble mean height valid Saturday has the ensembles placing the
trough axis over the California coastline...with little uncertainty.
This combo should help keep the marine layer rather deep at least
into the weekend.
Further out around Tuesday and Wednesday the trend in the ensemble
mean for the GFS shows the trough may be deeper than is indicated in
the deterministic runs...so the warmup for late next week might be
very minor.
&&
Aviation...
222015z...coast/valleys...stratus has retreated off the
coast...except for southern San Diego County where the eddy is
keeping it right along the coast. Stratus will push back into the
coastal airports between 23z-03z this evening...spreading to the
lower coastal slopes of the mountains overnight with bases around
1500-2000 feet mean sea level and tops around 3000 feet mean sea level. Expect clearing to the
coast by 18z Thursday morning...possibly sticking to the southern
San Diego coast again into the afternoon.
Mtns/deserts...mostly clear with unrestricted visible through Thursday
morning. West winds with surface gusts to 40 knots will continue over the
mountains and deserts this afternoon and evening...weakening
tonight...returning slightly weaker Friday afternoon.
&&
Marine...
a 3 feet...16 second period period southwest swell will continue surf of
3-5 feet and the potential for strong rip currents into the weekend. A
6-8 feet short-period northwest swell will move into the outer coastal
waters this afternoon through Thursday resulting in rough seas near
San Clemente Island and a slight increase in surf along exposed west
facing beaches. Swell and surf will gradually subside through the
weekend into early next week.
&&
Sgx watches/warnings/advisories...
Wind Advisory from 4 PM today until 2 am Thursday for areas of the
mountains and deserts.
&&
$$
Public...small
aviation/marine...ts
