Atherton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

548
FXUS66 KMTR 211552
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
852 AM PDT Sat Jun 21 2025

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 400 AM PDT Sat Jun 21 2025

Elevated fire weather concerns continue through Sunday morning.
Otherwise quiet weather on tap after that with near normal
temperatures.

&&

.UPDATE...
Issued at 850 AM PDT Sat Jun 21 2025

Skies are generally clear on this first full day of astronomical
summer. The forecast remains on track with gusty winds and dry
afternoon humidities resulting in elevated fire weather threat for
the interior through the day into the early part of Suunday
morning.

DialH

&&

.SHORT TERM...
(Today and tonight)
Issued at 400 AM PDT Sat Jun 21 2025

The forecast remains on track with an upper level low tracking into
the Great Basin, deepening the larger upper level trough. Flow
will remain onshore with gusty winds picking back up by mid to
late morning. The pressure gradient looks to support another gusty
day with gusts peaking 25-35 mph, with gusts up to 40 mph, or
locally higher. for areas along the coast or at wind prone gaps
and passes. The forecast looks to remain dry, especially for areas
above the marine layer where recovery is expected to be poor. The
marine layer should be around 1500-2000ft. Given these conditions
and cured grasses and dried shrubbery, elevated fire weather
countdowns will continue.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 400 AM PDT Sat Jun 21 2025

Saturday evening into Sunday morning, winds look to remain breezy
before beginning to ease. Upper level troughing looks hold, though a
perturbation forms causing the through to deepen a bit more over
Central CA. This then looks to essentially park itself over CA and
NV through midweek with more zonal flow returning mid to late week.
Weather should generally be more typical for this time of year,
seasonable temperatures, nighttime and morning stratus, and
generally quiet weather.

&&

.AVIATION...
(12Z TAFS)
Issued at 503 AM PDT Sat Jun 21 2025

Currently VFR at the terminals with very patchy stratus. High
confidence in VFR through the TAF period. Strong and gusty onshore
winds are expected through the TAF period with the help of the
passage of an upper-level shortwave trough.

Vicinity of SFO...Currently VFR with westerly flow. High confidence
in VFR through the TAF period. Westerly/westnorthwesterly winds will
strengthen through the morning with gusts up to 35 knots to be
expected in the afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with southwesterly flow at
MRY and VFR with westerly flow at SNS. High confidence in VFR
through the TAF period, although there is some IFR stratus within
the vicinity of the terminals. Gusty onshore winds will prevail
through the TAF period.

&&

.MARINE...
(Today through Thursday)
Issued at 850 AM PDT Sat Jun 21 2025

Widespread hazardous marine conditions are expected over the
waters through early Sunday morning in the form of near-gale
northerly breezes, severe gale force gusts, and rough to very
rough seas. The bays will be more sheltered, but will still
experience fresh to strong northwesterly breezes. Winds will
subside on Sunday, with fresh to strong northwest gusts and
moderate to rough seas through the end of the next work week.

&&

.FIRE WEATHER...
Issued at 557 AM PDT Sat Jun 21 2025

Elevated to near critical fire weather conditions continue today
across the interior Central Coast, East Bay Hills, and interior
North Bay as another dry day with moderate to poor RH recovery is
expected for interior locations and areas of higher elevation,
especially for those above the marine layer. Winds will be breezy
to gusty as well, peaking around 35 to 45 mph, perhaps locally
higher at exposed elevations and wind prone gaps. Breezy to gusty
winds look to hold through Sunday morning, with winds gradually
easing throughout the day. There should be some improvement in
humidity as well, especially if the marine layer is able to
deepen. Widespread critical fire weather conditions are not
expected within the district today, although the fire weather
threat will increase once again for areas closer to the Central
Valley. The fire weather threat will continue to diminish Sunday
into the early part of next week with the gusty winds further
relaxing, although humidity values in the interior will be slow to
rise.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for Mry Bay-SF Bay N
     of Bay Bridge.

     Gale Warning until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 10-
     60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 AM PDT this morning for Pigeon Pt
     to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Gale Warning until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 0-
     10 nm-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Sarment
MARINE...DialH

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