Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
311 am PDT sun Aug 30 2015
Synopsis...a dry upper trough will remain anchored near the West
Coast through most of the week. Temperatures near the coast will
be near seasonal norms...while inland areas will generally be
cooler than normal over the next seven days. No rain is expected.
Discussion...as of 3:10 am PDT Sunday...thanks to a cold front
that swept across our region yesterday drier and cooler air has
settled across our area today. Many locations are running 5 to 10
degrees cooler compared to yesterday while dewpoints are also
running 5 to 10 degrees drier in many spots. Satellite product
shows patchy clouds both along the coast...into the East Bay and
Santa Clara Valley. Would expect them to burn-off fairly fast
leading to mostly sunny conditions by afternoon. Highs will be in
the upper 60s to upper 70s at the coast with 80s for most inland
spots. Northwesterly winds are expected to increase through the
day. Many spots could see gusts of at least 15 miles per hour by the
afternoon with locally higher values expected.
Overall looks like a very quiet week for our region as
synoptically a longwave trough will be centered over the western
Continental U.S. While a ridge of high pressure remains over the east. Temperatures
will generally be at to a bit below normal inland while coastal
spots will be at or slightly above normal. Overnight cloud cover
is expected to increase each night as the marine layer deepens and
the onshore flow slightly increases. The storm track will stay
well to the north through the period.
Temperatures will rebound a bit by the end of the week as the trough shifts
to the north and east. No indication of rain returning to our
area through at least the middle of next week.
Aviation...as of 10:54 PM PDT Saturday...drier air on west-northwest
surface winds continues to move in over the entire area. Satellite
shows some patchy stratus developing over Sonoma and Marin counties
and over northern San Mateo County. Much drier air will also sweep
in from the west tonight within a deeper layer of the atmosphere
resulting in increased radiational cooling. Because of this expect
additional stratus and fog patches tonight into Sunday morning.
Clearing skies expected by middle-late morning Sunday.
Vicinity of ksfo...tempo broken MVFR ceiling forecast tonight...MVFR ceiling
prevailing 11z-17z. VFR is very likely to return middle-late Sunday
morning. West winds 20 gusts to 28 knots forecast 21z Sunday to
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...drier air is moving in on west-northwest winds.
It's mostly clear to clear around the area per satellite and
observations. Localized IFR possible tonight...coverage should be
at a minimum. VFR likely Sunday.
Beaches...as of 10:45 am PDT Saturday...a long period west swell
has arrived and will continue to advance on west facing beaches
through the weekend and into early next week. These long period
swells can produce hazardous rip currents that can quickly pull
swimmers out to sea. The highest risk of hazardous conditions will
be this weekend when onshore winds weaken and the period increases
from 15 to 18 seconds. Swimmers caught in a rip current should
swim parallel to the coast to escape the rip currents.
Marine...as of 3:10 am PDT Sunday...northwest winds will
increase over the coastal waters through the weekend. Gusty west
winds are forecast Sunday afternoon and evening over the northern
San Francisco Bay. A long period west swell will continue to move
through the waters through the weekend and into early next week.
... Pinos to pt Piedras Blancas 0-10 nm
Small Craft Advisory...sf Bay from 2 PM
Public forecast: Bell
marine: west pi
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