Atherton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

939
FXUS66 KMTR 011824
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1124 AM PDT Sun Jun 1 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 912 AM PDT Sun Jun 1 2025

Cooling trend for inland areas today as onshore winds return to
the region. A seasonal weather pattern is forecast for the
upcoming week with near normal temperatures, dry conditions and
breezy onshore winds, strongest during the afternoon and evening
hours.

&&

.UPDATE...
Issued at 912 AM PDT Sun Jun 1 2025

Visible satellite shows morning low clouds hugging the coastline
and pushing into SF bay with an inversion depth around 1500 feet.
Otherwise a sunny start for much of the interior North/South and
East Bay. Morning temps already running as much about 10 degrees
cooler than yesterday morning for places like Livermore thanks to
increasing onshore pressure gradient of 3.3 mb SFO-Sac, strong for
this early in the morning. Upper level disturbance will drop down
the coast later today into tonight. 12z model guidance keeps
instability to a minimum with very dry atmospheric profile, thus
chance of any rogue thunderstorms for our CWA looks to be less
than 5%. Some breezy northerly wind work down the Sac Valley
tonight and will skirt into the Napa hills late tonight into
Monday morning. However fire weather concerns remain minimal as RH
recovery will be moderate to good.

That shortwave pushes into SoCal by Tuesday setting up a week of
seasonal and dry weather with temps mainly 60s coast, 70s bayside
and 80s inland.

&&

.SHORT TERM...
(Today and tonight)
Issued at 305 AM PDT Sun Jun 1 2025

Key Messages

-Pattern change and cool down today

Upper level troughing to our northwest will continue to deepen today
and enter northern CA while the cutoff low to the west of Baja
California drifts north and eastward. These systems will continue
to cut off our access to high pressure, leading to cooler weather
spreading over the region. Interior locations for the North Bay
and Central Coast will remain near normal for this time of year,
where highs will span the 80s. Elsewhere near normal to below
normal temperatures are expected as temperatures range from the
mid 50s to low 70s, with it being warmer as you go inland.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 305 AM PDT Sun Jun 1 2025

Key Messages

-Marine layer returns, more seasonal weather by mid to late week
-Small warm up possible by next weekend

The trough entering into northern CA on Sunday is forecast to become
a cutoff low late Sunday night into early Monday morning. This
system is expected to gradually slide down the CA coast on
Monday, making it to southern CA by Tuesday. As it does this, the
cutoff low from Baja gets ejected into the Desert Southwest.
Cooler weather remains in the forecast during this time frame,
with the marine layer making a return Sunday night into Monday
morning. There is some uncertainty as to how late Monday into
Tuesday looks. Some models try to spin a ribbon of moisture up
into our next of the woods as the low traverses south.
Additionally some models throw some instability into this mix,
which support isolated thunderstorms. Confidence remains low to
add thunderstorms to the forecast at this point. There`s a better
chance of seeing fair weather cu develop over our area rather than
thunderstorms at this time. Will need to keep an eye out on the
forecast to see if any additional CAMs tap into this solution.
Cooler to near seasonal weather is on tap through at least
midweek. We could see a small warm up by next weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1124 AM PDT Sun Jun 1 2025


Cloud cover is eroding for all but the immediate coast, but CIGs
look to clear or at least scatter for all of the TAF sites by the
mid afternoon. Expect moderate to breezy winds through the afternoon
and into the evening. CIGs rebuild in the early evening along the
coast, the SF Bay and for the Monterey Bay, but coverage will be
spotty. More consistent MVFR CIGs affect the Monterey Bay terminals
into the night as winds reduce across the region, while cloud cover
retreats around the SF Bay. A surface low nears the region in the
late night and early morning, leading to some pronounced wind shifts
and reversals for sites closer to the coast. It will also pull cloud
cover away from the coast, leading a reduction in CIGs at HAF, and
Mid-morning clearing for the Monterey Bay. Inconsistent IFR CIGs
also look to affect APC in the late night and into the early morning
before eroding. Moderate winds and Widespread VFR is expected by
late Monday morning


Vicinity of SFO...Expect VFR to last into the late evening. Breezy
to gusty west winds last into the late evening  before reducing as
scattered low clouds build around the SF Bay. These clouds look to
inconsistently fill over SFO and OAK into the first part of the
night before retreating. Winds stay light until the mid morning
before becoming more moderate and northeasterly, but then switch
back to being westerly into Monday afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Cloud cover scatterers into the afternoon as
winds increase. Expect winds to reduce again into the evening as
cloud cover begins to rebuild. An otter eddy looks to form in the
center of the Monterey Bay in the early evening, causing cloud cover
to inconsistently fill over the terminals through the evening and
into the night. CIGs become more consistent into the late night
with winds reducing further. A surface low moves into the area and
just west of the Monterey Bay into mid Monday morning. This will
pull cloud cover away from the terminals before the end of the TAF
period.

&&

.MARINE...
(Today through Friday)
Issued at 1124 AM PDT Sun Jun 1 2025

The outer waters continue to see strong to gale force gusts
continue across the outer waters and these winds look to last
into early work week. The strongest winds will be over the far
northern outer waters where occasional storm force gusts will be
possible from Point Arena to Point Reyes. Rough seas continue over
the outer waters with significant wave heights building to 10 to
15 feet across the southern outer waters and up to 22 feet across
the northern outer waters Sunday evening into Monday morning.
Winds gradually ease by Tuesday but significant wave heights will
remain elevated through late next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Monday
     for SF Bay N of Bay Bridge.

     Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena
     to Pt Reyes 0-10 nm.

     Gale Warning from 3 PM this afternoon to 3 AM PDT Monday for Pt
     Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pt Reyes to
     Pigeon Pt 0-10 nm.

     Gale Warning until 9 AM PDT Monday for Pt Arena to Pt Reyes 10-
     60 NM.

     Small Craft Advisory until 3 PM PDT Monday for Pigeon Pt to Pt
     Pinos 10-60 NM.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Murdock
MARINE...Murdock

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