Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 210536
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1036 PM PDT Thu Apr 20 2017
.SYNOPSIS...High pressure building off the coast will bring a
warming and drying trend to the Bay Area and Monterey Bay region
through Friday. Temperatures will slightly cool over the weekend
although dry conditions will continue.
.DISCUSSION...as of 9:00 PM PDT Thursday...Upper level ridge off
the west coast will move over the west coast on Friday. Surface
high pressure off the California coast will build into Washington
and Oregon tonight producing a dry northerly flow over the area
and getting rid of the moisture in the lower levels. Mostly clear
skies are expected tonight and Friday which will lead to 5-10
degrees of warming on Friday.
The upper ridge will move inland on Saturday while the surface
high breaks down as a frontal system moves into the Pacific
Northwest. Precipitation will stay north of the CWA but
temperatures Saturday will be 5-7 degrees cooler.
A zonal flow will develop over the area Sunday through Tuesday
with the storm track staying to the north resulting in seasonal
temperatures. A strong low pressure system moves into the Pacific
Northwest Tuesday night and Wednesday bringing a chance of rain to
the North Bay and a slight chance of rain to the SFO Bay Area.
The latest runs of the ECMWF and GFS both forecast rain for the
North Bay at that time so pops have been increased in the extended.
.AVIATION...as of 10:35 PM PDT Thursday...For 06Z TAFs...Mostly
clear skies will prevail through the forecast period with mainly
light winds aside from the typical afternoon seabreezes. Patchy
low clouds are possible overnight however confidence is low.
Vicinity of KSFO...VFR. Light winds expected overnight with an
afternoon seabreeze around 15 kt after 22z.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR. Light and variable winds expected
overnight with an afternoon seabreeze around 15 kt after 21z.
Some low clouds overnight may briefly bring MVFR before sunrise.
.MARINE...as of 8:57 PM PDT Thursday...Moderate northwest winds
will prevail through the remainder of today and through tomorrow
as high pressure builds off the coast. A moderate but gradually
decreasing west swell is moving through the coastal waters today
.Tngt...SCA...Mry Bay until 3 AM
SCA...Pt Arena to Pt Reyes 0-10 nm until 3 AM
SCA...Pt Reyes to Pigeon Pt 0-10 nm until 3 AM
SCA...Pigeon Pt to Pt Pinos 0-10 nm until 3 AM
SCA...Pt Arena to Pigeon Pt 10-60 nm until 3 AM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 AM
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
PUBLIC FORECAST: W Pi
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