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

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FXUS66 KMTR 280008

Area Forecast Discussion
National Weather Service San Francisco Bay Area
508 PM PDT Sun May 27 2018

.SYNOPSIS...A robust warming trend is forecast through Memorial
Day as high pressure builds over California and onshore flow
weakens. Coastal cooling will develop by Tuesday with more
widespread and significant cooling expected by Wednesday as a dry
upper trough develops over the state.

&& of 01:35 PM PDT Sunday...Two parts of today`s
forecast verified well: much warmer and less cloud cover. The
forecast did come up a little short regarding the amount of
clearing along the immediate coast. Afternoon visible satellite
still shows pesky low clouds hugging the immediate coast from near
the Golden Gate southward to Big Sur. There is a slow trend for
some additional clearing along the coast, but it looks like some
clouds may linger through the afternoon. None the less, interior
locations warmed up nicely today with temps in the 70s to lower
80s, which is about 15-20 degrees warmer than 24 hours ago.

No major changes to the overall forecast. High pressure will
continue to build across NorCal through Monday night. The warming
noticed today across the interior will warm a few more tomorrow.
In fact, some interior spots will dip into the lower 90s. Likely
some of the warmest temps observed in a few weeks. Max temps in
the 80s and 90s tomorrow would be 5-10 degrees above normal for
late May. Individuals with outdoor activities should be mindful of
the warmer temperatures and plan accordingly - stay hydrated,
wear sunscreen, take breaks, etc. Simply put, tomorrow could be a
shock for some as it will feel noticeably warmer across the
interior. At the coast is a different story as onshore flow
lingers. Similar to today, pesky low clouds will keep the
immediate coast in check with seasonable temps.

By Tuesday the ridge of high pressure moves eastward as a trough
of low pressure begins to deepen off the West Coast. Stronger
onshore flow returns reinvigorating the extent of night/morning
clouds. Max temps will begin the downward trend on Tuesday.

By Wednesday/Thursday the upper trough is forecast to be over the
Bay Area with some of the coldest weather of the upcoming week. By
Thursday max temps will struggle to even hit 70 across the
interior, which is about 5-10 degrees below normal. What a change
from Monday to Thursday.

A slight warming trending will develop Friday into next weekend as
high pressure returns with warming 850mb temps.


.AVIATION...As of 4:45 AM PDT Sunday...For 00z TAFs. Dry
northerly flow over the region is systematically clearing all
clouds from the region from north to south. Mainly clear skies
expected through the forecast period across most terminals. The
only fly in the ointment may be lingering low clouds over the
Monterey Bay this evening that may push inland tonight. Confidence
is low with respect to cigs returning over KMRY and KSNS.
Otherwise moderate onshore flow will continue through this evening
then ease becoming light and locally variable overnight.

Forecast confidence: Moderate-high

Vicinity of KSFO...VFR conditions will prevail through the
forecast period. Moderate west winds around 15 to 20 kt will
continue through this evening then ease becoming light overnight.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR conditions will likely prevail
through tonight however confidence is low as the patch of low
clouds currently over the bay may push inland this evening or
overnight bringing cigs to KMRY and KSNS. Light winds.

&& of 04:55 PM PDT Sunday...Moderate to strong northwest
winds will continue through this  evening and into the upcoming
week, especially over the northern outer waters. Steep fresh swell
will be generated by the moderate to locally strong winds. The
pressure gradient is forecast to gradually tighten along the
northern California coast starting  Monday afternoon. This will
increase NW winds to gale force or  near gale force by Tuesday for
the outer waters through at least  Wednesday, before decreasing.
Very rough and erratic seas can be  expected with these winds.


     .Tngt...SCA...Mry Bay until 9 PM
             SCA...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM
             SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 12 AM




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