Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
120 PM PDT Monday Sep 1 2014
Synopsis...temperatures return to near seasonal averages by Tuesday
and will persist through late week along with dry weather conditions.
Discussion...as of 01:18 PM PDT Monday...the 12z upper air
sounding from Oakland this morning showed weak offshore flow in
the 2-6kft layer that resulted in warmer temperatures aloft. This
has generally translated to a warm up in surface temperatures as
expected with a middle/upper level ridge axis also stretching across
the region. The Fort Ord profiler is also showing these warmer
temperatures above the marine layer...which has kept coastal
clouds just off the central coast. Given a deepening marine
layer...should see development of coastal clouds late this evening
that will likely spread inland overnight.
Slightly cooler temperatures are then expected for tomorrow as the
ridge weakens ahead of the next middle/upper level trough set to drop
southward out of the Gulf of Alaska and down into the Pacific
northwest during the next couple of days. In addition...onshore flow
and deepening marine layer will help bring temperatures back to near
seasonal averages by Tuesday. The forecast models continue to keep a
lingering trough draped over the region through late week. With
limited moisture to work with...not expecting any measurable
precipitation through the extended forecast period and temperatures
will be within a few degrees of normal.
The medium range models do not show much change in the upper level
pattern as we head into next weekend. With this...will continue to
keep temperatures near what is typical for late Summer and keep any
mention of precipitation out of the extended forecast.
Aviation...as of 10:20 am PDT Monday...patchy stratus confined to
areas along the coast this morning and all terminals clear.
Northerly gradient is set to weaken however with somewhat shallow
marine layer stratus likely to be patchy again tonight.
Vicinity of ksfo...VFR today. West winds to around 15 knots. Stratus
tonight expected to be patchy and mostly confined to coast and
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...VFR today. Light to moderate sea
breeze. Stratus to return late evening.
Marine...as of 01:18 PM PDT Monday...high pressure extends from
the eastern Pacific into the Pacific northwest. Moderate northwest
winds continue along the California coast. The winds will decrease
over the southern waters Tuesday through Thursday as a thermal
trough develops along the coast.
... Arena to pt Reyes 10-60 nm
Small Craft Advisory...pt Arena to pt Reyes 0-10 nm until 9 PM
Small Craft Advisory...pt Reyes to Pigeon pt 10-60 nm
Small Craft Advisory...sf Bay north of the Bay Bridge until 9 PM
Small Craft Advisory...Pigeon pt to pt pinos 10-60 nm until 3 am
Public forecast: rgass
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