Small Craft Advisory 106, NWS San Francisco Bay Area, CA

Area Forecast Discussion
National Weather Service San Francisco Bay Area
1040 PM PDT Fri Jun 8 2018

.SYNOPSIS...Cool and breezy weather is forecast region-wide on
Saturday as an upper level system pushes inland to our north.
Slight warming is forecast for Sunday, although breezy conditions
will continue. Robust warming is then expected on Monday and
Tuesday as high pressure builds over California. Temperatures are
expected to return to near seasonal during the second half of
next week.

&&

.DISCUSSION...As of 8:55 PM PDT Friday...Evening satellite shows
an unseasonably deep and cold upper trough off the coast of the
Pacific Northwest. A surface cold front is currently spreading
rain into coastal Washington and Oregon. Latest NAM and HRRR
models show rain with the cold front making it as far south as
Point Arena by late tonight, but not quite making it into Sonoma
County. In any case, we may see some patchy drizzle overnight and
into early Saturday as the surface boundary interacts with the
marine layer.

The primary impact of this incoming system will be cooling
tomorrow, along with breezy conditions. Highs on Saturday are
forecast to be as much as 15 degrees cooler than today as 850 mb
temperatures drop as low as 4 degrees C in the North Bay. West to
northwest winds will increase by midday tomorrow and breezy to
locally blustery conditions are expected by afternoon. Wind gust
of between 30 and 40 mph are likely during the afternoon and
evening hours. The marine layer will definitely mix out by midday
tomorrow.

The upper trough is forecast to move well off to our east by
Sunday and slightly warmer temperatures are expected during the
second half of the weekend. However, breezy conditions are
expected to persist through Sunday evening.

The models agree in building an upper ridge over California on
Monday and Tuesday and reducing onshore flow as well. The result
will be a robust warming trend early in the work week, especially
inland. For example, Livermore's high is forecast to increase from
the lower 70s tomorrow to the mid 90s on Tuesday. Persistent
onshore flow will keep most coastal areas from warming above the
mid 70s on Monday and Tuesday.

The ridge is forecast to weaken by the middle of next week as a
trough moves inland to our north. Temperatures will begin to cool
on Wednesday and then drop back to near normal by Thursday and
Friday.

&&

.AVIATION...As of 10:40 PM PDT Friday...For 06z tafs. Coastal
stratus has begun to move inland with a couple of sites reporting
IFR cigs. Stratus is expected to continue to move inland and down
the valleys overnight. Confidence remains low on the timing and
extent of low cloud coverage. Winds will continue to subside
overnight before increasing once again by tomorrow afternoon.
Sustained winds 15-20 kt with gusts 25-30 kt can be expected again
in the afternoon with locally higher speeds and gusts at KSFO.

Vicinity of KSFO...KSFO continues to see gusty winds blowing
patches of stratus over the terminal creating IFR conditions.
Sustained winds and gusts have reduced since late this afternoon
to around 15 kt gusting to 20-25 kt. Should the winds continue to
subside, a short VFR window could be possible. MVFR/IFR cigs are
expected to settle in over the next few hours and last into the
morning. Winds will re-strengthen by late tomorrow morning and
return to gusting to over 30 kt by 20-21z in the afternoon.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...MVFR/IFR cigs have begun to move into
KMRY. Occasional SCT cigs will be possible at KMRY over the next
couple of hours before IFR cigs prevail through the morning. KSNS
is also expected to see low clouds in the next couple of hours
that last through the night. Gusty westerly winds are once again
in the forecast for late tomorrow morning through the afternoon
and evening.

&&

.MARINE...as of 08:46 PM PDT Friday...Gusty northwest winds will
continue across the coastal waters as an upper level trough and
associated cold front move through the region tonight. Winds will
remain gusty through at least the weekend as high pressure sits
over the eastern Pacific. Afternoon and evening winds are expected
to be gusty across the bays as well. Strongest winds are forecast
along the coast, especially along the Big Sur coast where gale
force winds will be possible starting tomorrow afternoon.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm from 3 AM
             SCA...Pt Arena to Pigeon Pt 10-60 nm from 3 AM
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm

&&

PUBLIC FORECAST: Dykema
AVIATION: AS
MARINE: AS

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