FXUS66 KMTR 211200
Area Forecast Discussion
National Weather Service San Francisco Bay Area
500 AM PDT Mon Aug 21 2017
.SYNOPSIS...Look for overnight clouds at the coast and adjacent
inland spots through most of the period. Temperatures will begin
to warm again later in the week as a ridge of high pressure starts
to build into our region.
.DISCUSSION...as of 3:00 AM PDT Monday...Over the past few hours
we have seen a substantial increase in clouds across a good
portion of our CWA. Unlike most days when other weather parameters
are the focus, clouds are the main story today as many people will
be trying to view (don`t forget the proper eyewear!) the solar
eclipse this morning. Unfortunately, guidance has become a bit
more pessimistic with the last couple of runs and now shows a
better shot of clouds impacting portions of the San Francisco Bay
Region. For those looking to view it, advice remains the same --
head well inland for your best shot. Please see the "eclipse"
section below for specific viewing times.
Outside of the eclipse, quiet weather will be the rule for the
entire week. Temperatures will be seasonably cool inland today
into Wednesday as an upper level low and shortwave trough remain
near our CWA. Instead of seeing a typical 40 degree gradient, we
will generally see half of that. Coastal spots will be in the 60s
to mid 70s with mid 70s to around 90 inland.
Toward the end of the week temperatures will begin to increase
(especially away from the coast) as a ridge of high pressure
centered near the Four Corners builds into California. Highs will
move back to above normal levels with vary warm conditions likely
.AVIATION...As of 4:57 AM PDT Monday...For 12z TAFs. Mid-level
and surface low pressure about 100 miles off the coast of Southern
California will tamper with the typical wind pattern across the
district a tad today. Otherwise, stratus quo will continue through
mid to late morning. Satellite shows extensive stratus filling in
nicely at this hour, under a 2400 foot marine layer. All taf
sites show MVFR/IFR cigs per 11z surface observations, minus KSFO
at VFR. Expect cigs to continue through 16-17z before clearing
occurs. Mid-level moisture from aforementioned low will bring in
SCT-BKN around 10-15k feet through the day. Light and variable
winds will turn westerly at 10 to 15 kt this afternoon. Stratus
and fog is expected to redevelop tonight.
Vicinity of KSFO...Stratus expected to fill in over the next hour
or so over the terminal. MVFR expected through about 16z, then
VFR. Will amend timing if necessary. Southwest winds will turn
westerly and increase by 18-19z, though only expected to remain
around 15 kt this afternoon.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...MVFR/IFR through 17-18z, with low
confidence on exact clearing. Generally light onshore winds this
afternoon, around 10-12 kt, with winds being more southwesterly at
KMRY. An early return of stratus expected again tonight.
.ECLIPSE...Here are the times for the start, peak, and end of the
eclipse for Monday morning. The percent of obscuration for each
location is also listed.
........Santa Rosa...San Francisco...Oakland...San Jose...Monterey
.MARINE...as of 2:32 AM PDT Monday...Light and variable winds
will prevail over the coastal waters through about mid week, with
the exception of the northern San Francisco Bay zone, which will
be breezy during the afternoon and evening hours. As a result,
seas are anticipated to remain relatively tame, occasionally
choppy. High pressure builds in from the west by Wednesday,
increasing winds from the northwest.
.Tday...SCA...SF Bay from 1 PM
PUBLIC FORECAST: Bell
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Prepared by Boulder-Creek.com Weather at: Mon Aug 21 18:30:03 PDT 2017
From the National Weather Service