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Area forecast discussion 
National Weather Service San Francisco Bay area
242 PM PDT Monday may 25 2015

Synopsis...cooler than normal conditions will continue for at
least another day along with widespread clouds. Warmer conditions
are expected during the second half of the week...especially for
inland areas. However...coastal areas will see only limited
warming as an onshore flow remains in place.

&&

Discussion...as of 3:00 PM PDT Monday...clouds have burned-off
inland today although still remain fairly widespread along
the coast. Temperatures in most spots have been running close to
where we were yesterday at this time although a few pockets in the
North Bay are running 3 or more degrees cooler than Sunday
afternoon. With an onshore flow expected overnight plus a marine
layer over 2500 feet and plenty of upstream clouds...look for
another round of widespread overnight clouds tonight. Patchy
coastal drizzle is also possible. Similar conditions are forecast
for Tuesday and Tuesday night.

Conditions are expected to start to improve on Wednesday as a
ridge of high pressure builds in from the Pacific. 850 mb temperatures
and 500 mb heights will rise each day at least through Friday
allowing for highs to go back to at least normal values for inland
spots. Southern inland sections of Monterey County over to San
Benito County will likely see number going to above normal
readings with highs in the middle 80s to lower 90s. At the coast the
warm up will be more limited due to the cool sea surface
temperatures plus onshore flow at the surface. On Friday highs
will range from lower 60s at some beaches up to lower 90s for the
warmest inland sections. Around Santa Clara Valley...most places
will be in the upper 70s to lower 80s. The ridge will start to
break down by next week leading to some cooler readings.

Both of the longer range outlooks...6 to 10...and 8 to 14
day...indicate warmer than normal temperatures without any substantial
rainfall. If correct it would mean that the ridge has rebuilt over
our area.

&&

Aviation...as of 11:30 am PDT Monday...for 18z tafs. The marine
stratus deck is thinning out this morning and several holes of
clearing are evident on satellite imagery. MVFR ceilings will remain
through the day for areas with the strongest coastal influence...
including ksfo and kmry. Onshore flow will be light to moderate
with speeds 10 to 15 knots this afternoon and gusts up to 20 knots
possible. MVFR/IFR ceilings return this evening/tonight for all
locations.

Vicinity of ksfo... mixing out over the South Bay is spreading
northward towards the terminal this morning. Expect to see
clearing stall just short of the terminal as moist onshore flow
through the San Bruno gap will keep MVFR ceiling status quo over the
terminal. Ceilings may gradually rise from 1500ft to 2000ft through
the day before gradually descending after 03z Tuesday.

Ksfo bridge approach... clearing over the South Bay has lead to
VFR ceilings over ksmb with only a few clouds at or above 2000 feet on most of
the approach.

Monterey Bay area terminals... broken/overcast 1500-2000 feet through most
of the day. Satellite imagery shows breaks in clouds upstream of
the peninsula so intermittent VFR/scattered possible during the
afternoon. Light to moderate onshore flow.

&&

Marine...as of 3:00 PM PDT Monday...light to moderate west to
northwest winds persist over the central California coastal waters
over the next 24 hours. Winds weaken and back towards the west
through midweek then veer back towards the northwest and increase
later in the week. Predominately gentle seas through the period.



&&

Mtr watches/warnings/advisories...
... Bay north of the Bay Bridge until 9 PM

&&

$$

Public forecast: Bell
aviation/marine: drp

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