Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
1049 PM PDT Sat Aug 30 2014
Synopsis...dry weather conditions along with above normal
temperatures will continue through Labor Day. Cooling is then
forecast for Tuesday and Wednesday as an upper level trough
develops along the West Coast.
Discussion...as of 8:45 PM PDT Saturday...strengthening surface
high pressure to our north across western Oregon led to a tighter
north-S surface pressure gradient across northern California today and thus a
reduction in onshore flow across our area. So even though the
airmass aloft has cooled since yesterday (see 00z Oak sounding)...
afternoon highs were warmer in most areas today...particularly the
North Bay valleys where highs today were as much as 12 degrees
warmer than yesterday. Most locations experienced sunny
skies this afternoon and temperatures that were at least a few
degrees above normal.
Evening satellite imagery shows a few high clouds across the far
southern portion of our area and a patch of low clouds north of
Point Reyes. Otherwise skies remain clear. Expect low clouds to
gradually form along much of our coast overnight...but develop
only locally inland given the relatively shallow marine layer
(currently 1200 feet deep at fort ord) and rather weak onshore
flow. Temperatures on Sunday should be similar to what they were
today. Temperatures are then expected to climb a few degrees on
Labor Day as an upper ridge over the eastern Pacific edges closer
to the West Coast and onshore flow diminishes further.
A cooling trend is forecast for Tuesday and Wednesday as an upper
trough in the Gulf of Alaska sweeps through the Pacific northwest and far
northern California and triggers an inland push of marine air. Inland
temperatures are expected to drop by as much as 15 degrees from
Monday to Wednesday. And...by Wednesday temperatures are forecast
to be slightly below normal in most areas. Weak upper level
troughing is then forecast to remain near the West Coast during
the second half of next week and into next weekend...which should
keep temperatures slightly below normal inland. Coastal temperatures will
remain slightly warmer than normal as long as sea surface
temperatures remain relatively warm. However...persistent
northwest flow over the coastal waters the next few days should
increase upwelling and result in cooler water temperatures along our
Aviation...as of 10:46 PM PDT Saturday...stratus clouds are developing
along the coast and additional stratus is expected overnight. Sf Bay
Vicinity of ksfo...VFR.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...VFR continues near the Monterey Bay.
IFR is however forecast late tonight. VFR is forecast to return by
late Sunday morning.
Marine...as of 02:15 PM PDT Saturday...high pressure off the
northern California coast will bring moderate northwest winds
through Monday. Winds will diminish slightly on Tuesday and
Wednesday as thermal trough shifts to the coast.
... Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm
Small Craft Advisory...pt Arena to pt Reyes 10-60 nm
Small Craft Advisory...pt Reyes to Pigeon pt 10-60 nm
Small Craft Advisory...Pigeon pt to pt pinos 10-60 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 10-60 nm
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm
Public forecast: dykema
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