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Area forecast discussion 
National Weather Service San Diego California
141 PM PDT Friday Jul 31 2015

Synopsis...
isolated to scattered showers and thunderstorms possible through
this evening over portions of the mountains and high deserts as
monsoonal moisture lingers over the region. Dry air moving into
the region will create quiet weather this weekend into next
week...with night/morning low clouds along the
coast/valleys...high temperatures mostly near seasonal normals and
breezy westerly winds through mountain passes and along Desert
Mountain slopes.

&&

Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
counties...

At 1 PM PDT...water vapor satellite imagery displayed a broad
upper-level ridge stretching from eastern Texas to northern
Nevada...and an upper-level low around 650 miles SW of San
Francisco. Visible satellite showed some high clouds streaming
from south to north...and some cumulus build-ups over the
mountains and high deserts. Not much has developed so far
today...with only a few small returns picked up on radar north of
big bear. Lingering moisture and diurnal heating will continue the
possibility of isolated to scattered showers and thunderstorms
over the mountains and high deserts through this evening...with
the greatest chances over the High Mountain peaks. Drying in the
atmosphere will limit the coverage of storms compared to
yesterday.

Through next week...the ridge to the east will build southwest as
an upper-level trough lingers off of the West Coast. This will set
up dry...southwesterly flow aloft over the region. 500 mb heights
will build slightly over the area by middle next week...which will
raise high temperatures a few degrees...and create a shallower
marine layer. Before then...night/morning low clouds will reach
the far inland valleys this weekend...then remain restricted to
the coast/coastal valleys for next week. 31/1200 UTC GFS and
European model (ecmwf) differ in the extended with the location of the upper-level
trough. The European model (ecmwf) digs it along the coast down to socal...while
the GFS has higher heights over the region with the ridge closer
to the southeast. Currently...confidence is leaning to near seasonal
weather with the GFS solution. Onshore pressure gradients will
create breezy westerly winds through mountain passes and along
mountain desert slopes each afternoon/evening. High temperatures
along the coast will be near normal through the period...with
inland high temperatures rising from 5 to 10 degrees below normal
today and this weekend to near seasonal normals next week.

&&

Aviation...
312000z...coast/valleys...stratus with bases near 1500
feet mean sea level and tops 2000-2500 feet returning to the coastal airports 01/00-
03z and spreading well into the valleys through 12z lclly obscuring
higher terrain. Otherwise...scattered clouds at or above 20000 feet mean sea level and
unrestricted visible through Sat morning.

Mtns/deserts...sct-bkn clouds at or above fl250 and unrestricted visible through
Sat morning. Areas of cumulus/towering cumulus with bases near 8k feet along the
mountain crests....spreading into the deserts through about 02z Sat
with isolated-scattered shra/tsra...mainly north of San Diego County. Isolated
storms with tops fl350-400 will contain strong uddfs and low level wind shear from
gusty outflow winds near the surface. Storms will dissipate shortly
after sunset.

&&

Marine...
100 PM...except for wind gusts of 20-25 knots over the outer waters
Sunday and Monday evenings for a few hours...no hazardous marine
weather is expected through Tuesday.

&&

Beaches...
100 PM...new south swell building in behind decreasing
southwest swell through the weekend. Moderate rip current risk
through the weekend.

&&

Skywarn...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

Sgx watches/warnings/advisories...

California...none.
Pz...none.

&&

$$

Public...jjt
aviation/marine/beaches...jad

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