Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
640 PM PDT Monday Jul 28 2014
Synopsis...mid-level moisture streaming across the region will
bring a slight chance of sprinkles and the possibility of a
thunderstorm through Tuesday morning. Otherwise...dry conditions
and temperatures near or slightly above normal can be expected
through the remainder of the week.
Discussion...as of 6:40 PM PDT Monday...middle level cloud over
Monterey and San Benito counties have significantly dissipated
this evening. Current Doppler radar depicts a few showers over
the Salinas valley near Gonzales as well as east and northeast
of Hollister. Clouds and showers over this area will continue to
dissipate as the monsoonal moisture associated with these clouds
pulls to the east and brings the threat of thunderstorms over this
area to an end. The chance of showers will persist through tonight
however given some lingering instability and added middle-level
moisture over the region.
Temperatures dropped an average of 5 degrees today as a result of
the increased cloud cover over the region. Some locations cooled
by as much as 15 degrees over yesterday. Nonetheless temperatures
were running near to slightly above normal for this time of year.
The threat of convection will shift northward tonight as a weak
disturbance passes by. A slight chance of showers and isolated
thunderstorms is forecast over the northern half of the region
through early Tuesday morning.
From previous discussion...the middle-level moisture will begin to
shift inland...away from the coast toward the latter half of the
work week as the ridge builds westward. This will bring an end to
rain chances with a decrease in middle to high level clouds. With the
middle/upper level ridge centered over the southwest portion of the
country...temperatures will continue to be near or slightly above
seasonal averages through next weekend across the San
Francisco/Monterey Bay areas.
Onshore flow and presence of the marine layer should keep
conditions cooler near coastal locations with overnight/early
morning low clouds. Meanwhile...inland areas well remain very warm
to hot. Otherwise...no major changes in the extended pattern and
will maintain dry weather conditions through the forecast period.
Aviation...as of 5:00 PM PDT Monday...low clouds have cleared
from most of the coast but continue to cling to the San Mateo
coast. Onshore gradients are weak and marine layer is around 1500
feet so clouds will be late to spread into the sfo Bay area and VFR
is expected through the Airport evening rush.
Vicinity of ksfo...VFR through the Airport evening rush. MVFR/IFR
ceilings after 08z.
Ksfo bridge approach...MVFR/IFR ceilings after 06z.
Monterey Bay area terminals...low clouds have cleared from the
coast and there is no sign of any development in the Bay yet. As a
result ceilings will be a little later in spreading into mry and sns
than yesterday. IFR after 04z at mry and 05z at sns.
Marine...as of 02:30 PM PDT Monday...mid-level moisture will
continue to stream northward across the region through Tuesday and
bring a slight chance of showers and possibly a thunderstorm.
Otherwise...northerly flow will continue over the coastal waters
with generally gentle seas through the remainder of the week.
... Arena to pt Reyes 10-60 nm from 3 am
Small Craft Advisory...sf Bay north of the Bay Bridge until 9 PM
Small Craft Advisory...sf Bay south of the Bay Bridge until 9 PM
Public forecast: CW
aviation: west pi
marine: rgass/r canepa
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