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Area forecast discussion 
National Weather Service San Diego California
332 am PDT Tuesday Jun 30 2015

Synopsis...
high pressure over the Great Basin and low pressure off the
California and Baja California coasts will continue to direct a flow of
middle and high level monsoonal moisture across Southern California for
much of the week into early next week. This will support a chance of
thunderstorms through Thursday...mainly near the mountains and
portions of the deserts during the afternoon hours. Minor drying
is possible for Friday and Saturday with another chance for afternoon
thunderstorms for the mountains and deserts Sunday and Monday.
Temperatures will peak today...then cool to near average for
Friday through early next week. A shallow marine layer and weak
onshore flow will bring patchy night and morning low clouds and fog
near the coast and western valleys at times.

&&

High pressure over the Great Basin and low pressure off the
California and Baja California coasts will continue to direct a flow of
middle and high level monsoonal moisture across Southern California for
much of the week into early next week.

Monday evening soundings showed middle level moisture between 500 and
600 mb with drying aloft. Thunderstorms did occur Monday during
the late morning and early morning over southern portions of the
San Diego County mountains. But the moisture distribution by
evening was a little higher than optimal for thunderstorm
development.

This general pattern will hold through Thursday with a slight
chance of thunderstorms near the mountains each afternoon. Some
models do show nocturnal moisture moving across southwesternsan
Bernardino and western Riverside counties tonight and again
Wednesday night. Some of the models spit out some light
precipitation...but this may actually be nothing more than middle
level clouds with some virga or sprinkles.

Some minor drying is possible for Friday and Saturday with the
European model (ecmwf) showing a renewed chance for afternoon thunderstorms in the
mountains and deserts for Sunday and Monday afternoons.

Temperatures will peak today...then cool to near average for
Friday through early next week. A shallow marine layer and weak
onshore flow will bring patchy night and morning low clouds and fog
near the coast and western valleys at times. With the decrease in
higher level moisture...stratus coverage has increased over the
coastal waters...but not extending to the coast except along
portions of the Orange County coast and near the southern San
Diego County coast.

&&

Aviation...

300800z...coast/valleys...sct-bkn clouds at or above 10000 feet mean sea level through
Wednesday morning. Areas of marine stratus this morning...mainly
between 10-15z and extending inland only about 5 to 8 sm...and
mainly for the San Diego County coast. Bases are expected to be 800
to 1200 feet mean sea level with tops below 1500 feet mean sea level. The stratus deck will
dissipate by 17z. Lower clouds are not expected to reach ksna.
Patchy marine stratus again late tonight and Wednesday
morning...similar conditions to this morning.

Mtns/deserts...sct-bkn clouds at or above 10000 feet mean sea level through Tuesday. Cumulus/towering cumulus
developing after 18z through 22z with isolated rain showers/thunderstorms and rain and tops to
near fl300. Occasional gusty downdraft winds may result in strong
surface wind gusts and low level wind shear with patchy visible restrictions in blowing dust.

&&

Marine...
100 am...no hazardous marine weather is expected through Saturday.

&&

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...17
aviation/marine...jmb

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