Atherton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

677
FXUS66 KMTR 271151
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
451 AM PDT Fri Jun 27 2025

...New AVIATION...

.SYNOPSIS...
Issued at 300 AM PDT Fri Jun 27 2025

The June Gloom pattern continues with cloudy coastal conditions,
some sun for the afternoon, and returning cloud cover into the
evening. Expect a slight warm up for the interior today, but a
slow cooling trend for the weekend itself.

&&

.SHORT TERM...
(Today and tonight)
Issued at 300 AM PDT Fri Jun 27 2025

A very similar day to the previous one is ahead of us with low
coastal clouds lingering though the late morning, some breeziness in
the afternoon (especially along the coast) followed by coastal cloud
cover recoveries into the evening. It`s the typical June Gloom
pattern with some lightly warmer conditions for the interior than
previous days.

The overnight forecast package didn`t need to put too many
adjustments into the overall forecast, just some fine adjustments to
the regional winds, marine layer levels, and fog potential. But for
the most part, the forecast remains as advertised. Expect the
temperatures to peak in the upper 50s and low 60s along the coast,
into the 70s slightly more inland, and the 80s to low 90s for the
more inland areas that stay cloud-free today.  Temperatures will be
slightly slower to cool this evening across the region this evening,
and overall low temps will be slightly warmer for Friday night
into Saturday.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 300 AM PDT Fri Jun 27 2025

The upper-level pattern looks interesting.. for areas to the north,
while our pattern sits mostly in the in-between. A loop of low
pressures affect the the Pacific North West over the next few days
leading to some good and very persistent rain chances.. for just
them. Northern California will mostly stick to zonal flow, to the
point that any rain that pushes south of Oregon gets directed inland
and away from the Bay Area.

There will be a weak trough formation over the Bay Area and Central
Coast into the weekend, causing a slight deepening and inland
expansion of the of the marine layer. This trough will be very slow
to exit, but longer term models hint at a return to mostly zonal
flow again in the mid week, with another weak trough forming right
after.

What does that all mean for the forecast? Not a whole lot.

Temperatures along the coast and the slightly inland areas won`t see
much in the way of variation. Areas that are more inland will see
some cooler conditions as onshore flow continues and the marine layer
reaches farther inland. The pattern of cloudy mornings, clearing
afternoons, then cloudy evenings for the coast and near-coastal
areas will persist through the mid and long term forecast. The
switch from the trough to zonal flow could lead to increased
coastal fog chances, but mostly along the immediate coast.

So we`re far from dynamic weather, but this pattern does keep the
region away from any notable fire weather concerns, with even some
improvements to the interior humidities.

&&

.AVIATION...
(12Z TAFS)
Issued at 423 AM PDT Fri Jun 27 2025

Marine layer appears to be at approximately 1200ft and is
anticipated to remain around that height through the forecast
period. Stratus attempted but ultimately failed to fill in over
the Bay Area terminals. Farther south, the Monterey Bay terminals
have been hovering between IFR/LIFR most of the overnight. Short
term guidance is struggling with the intrusion of the marine layer
near the coastal sites.

Vicinity of SFO...VFR conditions are expected to persist through
the forecast period, however this is a low confidence forecast
with the edge of the marine stratus encroaching on both KSFO and
KOAK throughout the morning. MVFR/IFR ceilings are possible after
midnight into early Saturday morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR/LIFR ceilings will persist through
late morning, then VFR through the afternoon and early evening.
Low marine stratus is expected to fill in around 02z this evening
and continue through the TAF period with breezy onshore flow.

&&

.MARINE...
(Today through Wednesday)
Issued at 300 AM PDT Fri Jun 27 2025

Gale force winds have eased. Fresh to strong winds will continue
over the outer waters north of Point Reyes through Sunday.
Moderate to rough seas continue through the day today, with
significant wave heights subsiding Saturday into Sunday as winds
ease. The next round of elevated wave heights, strong
northwesterly winds, and moderate to rough seas begins Tuesday and
continues through late next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 PM PDT Saturday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...JM
MARINE...JM

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