Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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FXUS66 KMTR 241154

Area Forecast Discussion
National Weather Service San Francisco Bay Area
454 AM PDT Mon Apr 24 2017

.SYNOPSIS...A weak weather system approaching from the northwest
is expected to bring light precipitation to the North Bay this
morning, and may generate scattered showers farther south this
afternoon and evening. Periodic rain chances will continue in the
North Bay through Wednesday, with dry and seasonably cool weather
expected elsewhere. Dry weather along with a warming trend is
forecast across the region from Thursday through the weekend as
high pressure builds in. Locally breezy conditions are likely from
Thursday through Friday.


.DISCUSSION...As of 3:15 AM PDT Monday...Clouds have been on the
increase overnight as a weak weather system approaches from the
northwest. Models show light precipitation developing across
portions of the North Bay from about sunrise through late morning.
Most models also forecast widely scattered light showers south of
the Golden Gate during the afternoon and early evening hours.
Temperatures today will continue to be slightly cooler than

At least two additional weak systems are forecast to move in from
the northwest over the next few days and possibly produce local
light rain at times in the North Bay through Wednesday. From San
Francisco southward look for dry and seasonably cool conditions on
Tuesday and Wednesday.

A more amplified weather pattern is forecast to develop during
the second half of the week, with a deep trough forming over the
Intermountain West while a ridge builds offshore. In between,
across our area, a dry and brisk northerly flow will develop which
will likely result in gusty north winds from Thursday through early
Saturday, especially in the hills. A warming trend will begin on
Friday and continue into the weekend as the upper ridge offshore
edges eastward and over California.

The longer range models diverge somewhat after the weekend. The
GFS maintains a ridge and warm temperatures over California early
next week. The ECMWF retrogrades the ridge offshore, resulting in
some cooling. But both models maintain dry conditions into next

&& of 4:53 AM PDT Monday...For 12z Tafs. Mid and high
clouds will continue to stream across area terminals ahead of an
approaching weather system. Light rain showers expected after 15z
across the North Bay and will spread south through the day.
Showers will taper in the afternoon. Light to moderate west winds
will ramp up in the afternoon becoming moderate and locally gusty.

Vicinity of KSFO...VFR through much of the period. Light showers
will reach area terminals around 20z this afternoon and taper
after 00z. West winds around 15 kt anticipated to strengthen in
the afternoon to 15 to 20 kt with gusts to 25-30 knots possible.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals..VFR through much of the period. Light showers
will reach area terminals around 19z-20z this afternoon and taper
after 03z. Southwest winds around 5 kt will strengthen to around
10-15 kt with gusts to 15-20 kt in the afternoon.

&& of 04:35 AM PDT Monday...Moderate northwesterly winds
will prevail through much of the forecast period with strongest
winds confined along the coast south of Pt. Sur. Winds and seas
will increase Wednesday night into Thursday as high pressure
strengthens over the Eastern Pacific resulting in a tighter
pressure gradient across the coastal waters.


     .Tday...SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm




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