Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
255 PM PDT Tuesday Sep 2 2014
Synopsis...dry conditions will persist through the period along
with temperatures near or slightly below normal. Overnight clouds
can be expected in most locations.
Discussion...as of 3:00 PM PDT Tuesday...onshore flow at the
surface along with a 2000 foot marine layer has benn enough today to
keep clouds going along most of the coast this afternoon. In
addition, the stronger winds off the cooler waters have helped to
cool almost all locations. Over the North Bay some spots area
running more than 20 degrees cooler than this time yesterday.
Another round of widespread clouds is anticipated tonight along
the coast plus adjacent valleys. Drizzle is also possible along
the coast tonight.
Synoptically for the week a longwave trough will advance to near our
County Warning Area and remain fairly stationary into the weekend. With a 2000
plus marine layer expected plus onshore flow at the surface, temperatures
should end up being a few degrees cooler than normal -- especially
for inland spots. Expect 60s and 70s at the coast with middle 70s to
upper 80 for most inland locations.
For next week the European model (ecmwf) build a ridge of high pressure back into
our area with guidance suggesting another round of above normal
Aviation...as of 10:30 am PDT Tuesday...northwest flow through the
Golden Gate is making stratus at Oak unusually persistent while
mry Bay area terminals will be slow to burn off as well. Should see
full clearing by at least afternoon. Stratus likely to be more
widespread tonight as the marine layer deepens.
Vicinity of ksfo...VFR today. Light to moderate onshore winds.
Stratus late evening.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...northwest flow will keep ceilings at mry through
at least the rest of the morning with early return. Sns to burn
off within the next hour followed by early return this afternoon.
Marine...as of 5:00 am PDT Tuesday...high pressure continues off
the Pacific northwest coast. A thermal trough will shift to the
coast resulting in decreasing winds over the area except for the
outer waters north of Point Reyes.
... Arena to pt Reyes 10-60 nm
Small Craft Advisory...pt Reyes to Pigeon pt 10-60 nm until 3 PM
Small Craft Advisory...sf Bay north of the Bay Bridge until 9 PM
Public forecast: Bell
marine: west pi
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