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

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FXUS66 KMTR 021735

Area Forecast Discussion
National Weather Service San Francisco Bay Area
935 AM PST Tue Mar 2 2021

.SYNOPSIS...Dry and mild weather conditions continue with slight
cooling late in the week. Rain chances increase late Friday into
Saturday with the potential for unsettled conditions to persist
into early next week.

&& of 09:30 AM PST Tuesday...A chilly start for
some of our interior valleys as early morning temperatures dipped
into the mid 30s with a few spots in the low 30s. Luckily, morning
sunshine has warmed up many of those colder areas and most of our
current temps are in the upper 40s to mid 50s. Forecast is still
on track so no updates this morning. Will be concentrating on the
system that is forecast to move into northern and central CA
Friday evening through Saturday and adjust the forecast as needed
with respect to rain and winds.


.PREV of 03:23 AM PST Tuesday...A mid/upper level low
pressure system and associated trough remains well off of the West
Coast early this morning. It`s only impact to the region is
mid/high level clouds advecting inland across California as dry
weather conditions prevail at the surface. This system is forecast
to remain well enough offshore to maintain dry conditions over
the region before eventually dropping southward and then across
southern California on Wednesday. Day-to-day fluctuations in
temperatures are expected to be minimal through midweek, yet will
be at or above seasonal averages. Generally speaking, look for
upper 50s to lower 60s at the coast with more widespread 60s to
near 70 inland. Meanwhile, overnight lows will range from the
mid/upper 30s in the colder interior valleys with 40s elsewhere.

As the aforementioned system shifts inland over the Desert Southwest
through midweek, a mid/upper level trough will deepen over the
eastern Pacific late in the week. This system is then forecast to
shift eastward toward the West Coast late in the week potentially
bringing widespread precipitation to the region Friday night into
Saturday. However, the deterministic and most ensemble members only
indicate light precipitation for our region. Temperatures late in
the week and into the upcoming weekend will also cool as a result.

Beyond the upcoming weekend, the ensembles favor unsettled weather
conditions across our region heading into next week as troughing
persists over the eastern Pacific and along the West Coast. However,
this pattern would likely only result in light precipitation amounts
for our region. Seasonably cool conditions are also likely given
this pattern.

&& of 9:35 AM PST Tuesday...For the 18Z TAFs. VFR
conditions through the period. Satellite imagery shows some high
clouds over land and low clouds still well offshore over the
ocean. Still do not expect these clouds to impact the terminals,
though FEW-SCT cigs may reach some of the coastal taf sites.
Latest high res models have backed off on low level moisture
overnight, therefore have not added in BKN low cigs into the 18z
taf package. Expect increasing high clouds from the upper low
offshore as it continues to move towards southern California.
Generally light winds at or under 10 kt, onshore this afternoon.

Vicinity of KSFO...VFR, light and variable wind increasing to 10
knots W/NW in the afternoon and early evening.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR, continued SE winds this morning
around 5 to 10 kt should turn onshore this afternoon and evening.
Latest models have backed off on low level moisture along the
coast and over the Monterey Bay tonight/tomorrow morning. Elected
to keep BKN low cigs out of the tafs for now, but some SCT low
clouds still possible overnight.

&& of 08:57 AM PST Tuesday...A low pressure system over
the eastern Pacific will move across the waters into tomorrow,
though winds will remain generally light to locally moderate.
Building northwest swell will cause hazardous seas conditions for
smaller vessels later today into the evening. Winds will gradually
increase and turn southerly on Thursday ahead of the next frontal
system set to arrive Friday and Saturday. Moderate northwest swell
will over the next couple of days before a longer period northwest
swell arrives late this week.


     .Tday...SCA...Pt Arena to Pigeon Pt 10-60 nm from 12 PM
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 4 PM




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