High Surf Advisory 1, NWS San Francisco Bay Area, CA

Area Forecast Discussion
National Weather Service San Francisco Bay Area
152 PM PST Mon Jan 7 2019

.SYNOPSIS...An active weather pattern returns to the region on
Tuesday as deep moisture spreads inland ahead of an approaching cold
front. Gusty winds are also likely Tuesday into Wednesday morning
before the cold front pushes inland resulting in widspread
rainfall. Conditions dry out late Wednesday into Thursday before
unsettled conditions return late in the week and into the upcoming
weekend.

&&

.DISCUSSION...as of 01:50 PM PST Monday...Generally quiet weather
conditions persist over the region this afternoon with
temperatures ranging from the 50s to lower 60s. In addition, there
is an abundance of cloud cover region- wide as moisture aloft
advects inland ahead of our next approaching storm system. Look
for the lower levels to moisten up again overnight as south to
southwest flow increases overnight.

Light rain may develop along the coastal ranges as the
aforementioned onshore flow increases and PWAT values in excess of
1.00" advects inland. Rain will then develop over the North Bay
around or after sunrise Tuesday and continue through the day while
most areas to the south and inland remain mostly dry. Southerly
winds will also continue to increase during the day Tuesday with
wind speeds of 20 to 30 mph gusty up to 45 mph along the coast and
in the higher terrain across the region. Cannot rule out local gusts
in excess of 60 mph in the region's ridges and peaks. Thus, a Wind
Advisory has been issued from 7 AM Tuesday - 10 AM Wednesday as
winds will remain gusty. While the strongest winds will be in the
aforementioned areas, cannot rule out locally gusty conditions in
other coastal areas and adjacent inland areas during this time
frame. At this time, winds are not forecast to be as strong and
those on Sunday.

Widespread rainfall is then likely Tuesday night into early
Wednesday morning as the main cold front approaches the coast. Gusty
winds will persist and rainfall rates are likely to increase along
the coastal slopes. There will also be a slight chance of
thunderstorms associated with this frontal system late Tuesday night
into Wednesday. However, widespread thunderstorms are not likely and
impacts are anticipated to be minimal at this time. There will be an
increasing threat for urban and small stream/creek flooding from this
system as soils continue to become increasingly saturated from
previous rainfall events, especially in the North Bay and across the
Santa Cruz Mountains. In wake of the frontal passage, lingering
showers will be possible into the day Wednesday before drying
conditions develop Wednesday night.

Forecast confidence diminishes for the latter half of the week as
the ECMWF has significantly backed off on precipitation in days 4
through 8. However, previous thinking and the current GFS model
bring another mid/upper level system toward the coast Friday with
another round of widespread rainfall. The ECMWF now tracks the
mid/upper level low further to the south and is what likely resulted
in the drier forecast run at 12Z. An unsettled pattern looks likely
into the upcoming weekend as well as a series of storm systems move
into the West Coast. Will continue to monitor the forecast models in
the coming days and look for better consistency during the extended
time frame before making too many major changes. Stay tuned...

&&

.AVIATION...As of 9:42 AM PST Monday...For 18Z TAFs. VFR
conditions are forecast to prevail today as numerous mid/high
clouds pass over the area. Winds will be significantly lighter
today compared to the last few days. Light rain has been
introduced toward the latter end of the STS, SFO, and OAK TAFs as
the next system starts to impact the area.

Vicinity of KSFO...VFR conditions are expected to prevail at the
terminal today with passing mid/high clouds. Winds will remain
light through the afternoon hours, generally out of the
south/southeast. The next system will begin to impact the terminal
toward the end of the TAF period with increasing rain chances as
well as increasing southeast winds.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR conditions to prevail during the day
at SNS and MRY. Winds will remain rather light, though SNS could
see some occasional breezes between 10-15 kt this afternoon.

&&

.MARINE...as of 09:21 AM PST Monday...Southerly winds will
increase across the northern coastal waters this afternoon, across
the southern coastal waters by late tonight, and in the Bays by
late Tuesday. Gale-force winds are possible across the coastal
waters Tuesday and Tuesday night. Expect steep dangerous seas to
accompany the gale-force winds. Winds will diminish in all areas
by late Wednesday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...SCA...Pt Reyes to Pigeon Pt 0-10 nm from 3 AM
             SCA...Pigeon Pt to Pt Pinos 0-10 nm from 3 AM
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
             SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm from 9 PM

&&

PUBLIC FORECAST: RGass
AVIATION: Rowe
MARINE: Rowe

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
826 AM PST MON JAN 7 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0137 PM     NON-TSTM WND GST 2 N BURLINGAME          37.62N 122.37W
01/05/2019  M55.00 MPH       SAN MATEO          CA   ASOS

            SAN FRANCISCO INTERNATIONAL AIRPORT ASOS REPORTED 55 MPH
            PEAK WIND GUST ON JANUARY 5

0657 PM     NON-TSTM WND GST 2 N BURLINGAME          37.62N 122.37W
01/06/2019  E44.00 MPH       SAN MATEO          CA   ASOS

            SAN FRANCISCO INTERNATIONAL AIRPORT ASOS REPORTED 44 MPH
            PEAK WIND GUST ON JANUARY 6.

&&

ROWE