Area forecast discussion
National Weather Service San Francisco Bay area
1047 PM PDT Monday may 20 2013
..much cooler with breezy onshore winds Tuesday...
Discussion...as of 9:00 PM PDT Monday...upper level ridge over
the area combined with light offshore flow brought warm
temperatures to the district today with temperatures running about
15 degrees above normal.
It will turn much cooler Tuesday as an upper level low moves into
the Pacific northwest. The cool advection will cause airmass
mixing allowing winds to switch to onshore and become breezy. This
should keep stratus patchy in nature.
The upper low will remain over the Pacific northwest through
Thursday so temperatures will be cool through the period. It will
be a little warmer Friday as the low moves inland but another
upper trough will move over the area Saturday with trofiness
continuing through early next week. As a result temperatures for
the Memorial Day weekend are expected to be at or a little below
normal.
&&
Aviation...as of 10:46 PM PDT Monday...scattered high clouds will
continue to stream in from the west through tonight. Low clouds
will redevelop late tonight however the shallow marine layer will
keep stratus at the coast with minimal inland penetration. Moderate
confidence. Winds will ease a bit overnight with stronger winds
expected Tuesday afternoon.
Vicinity of ksfo...VFR conditions expected through late tonight.
Temporary IFR/MVFR ceilings possible between 11z to 16z. Moderate
confidence. Moderate west winds around 15 knots expected to continue
through tonight. Winds will gradually increase Tuesday with
sustained winds around 20 knots with gusts to 25 knots in the morning to
around 30 knots with gusts near 40 knots by the afternoon. An Airport
weather warning for ksfo will likely be issued for Tuesday
afternoon and evening.
Ksfo bridge approach...VFR conditions and west winds of 15 to 25
knots expected through forecast period.
Monterey Bay area terminals...VFR conditions will continue through
this evening with ceilings possibly returning after 10z. Moderate
confidence. Light to moderate onshore winds will continue through
tonight with strong west winds around 15 to 20 knots with gusts
between 20 to 25 knots expected Tuesday.
&&
Mtr watches/warnings/advisories...
... Arena to Pigeon pt 10-60 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm from midnight
Small Craft Advisory...Pigeon pt to pt Piedras Blancas 10-60 nm from midnight
Small Craft Advisory...pt Arena to pt Reyes 0-10 nm from midnight
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm from 3 am
Small Craft Advisory...sf Bay
&&
$$
Public forecast: west pi
aviation/marine: CW
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