849
FXUS66 KMTR 112310
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
410 PM PDT Sat Oct 11 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 145 PM PDT Sat Oct 11 2025

 - Cool and breezy this weekend

 - Widespread rainfall and isolated thunderstorms Monday and Tuesday
   with drier conditions returning by Wednesday afternoon

&&

.SHORT TERM...
Issued at 145 PM PDT Sat Oct 11 2025
(This evening through Sunday)

Mid/upper level troughing persist over the West Coast this afternoon
resulting in temperatures about 5 to 10 degrees below seasonal
averages. That said, seeing scattered cumulus over the higher
terrain with afternoon heating. Tonight will be cool with lows
dropping into the mid/upper 40s in the North Bay Valleys and
interior portions of the Central Coast. Elsewhere, upper 40s to mid
50s are expected into early Sunday morning.

There is about a 20%-30% chance of seeing fog in the North Bay
Valleys early Sunday morning before clearing skies return. Sunday
afternoon will feature mostly sunny skies and temperatures in the
60s near the coast to mid 70s across the interior. Cloud cover will
increase late in the day and into Sunday night as a reinforcing
mid/upper level low drops southward down the Washington/Oregon
coastline.

&&

.LONG TERM...
Issued at 145 PM PDT Sat Oct 11 2025
(Sunday night through next Friday)

The aforementioned low will drop down the California coast Monday
afternoon and bring with it rain and isolated thunderstorms. Rain
chances begin early Monday morning across the North Bay and increase
in coverage and intensity throughout the afternoon across the
Central Coast. Precipitable water values are forecast to range
between 0.80-1.00" at this time with CAPE of around 400 J/kg, thus
the potential for isolated thunderstorms. As a colder air mass
filters in from the north, expecting rain showers and isolated
thunderstorms to persist into Tuesday as the mid/upper level low
shifts inland either across the Bay Area or Central Coast on Tuesday
afternoon. Rain chances greatly diminish on Wednesday morning with
drier conditions returning by Wednesday night. Rainfall totals from
Monday through Wednesday currently look to range from 1.50"-2.50
(isolated up to 3.00") in the Santa Lucia Range and in the Santa Cruz
Mountains, with generally less than 1.50" elsewhere. Locally heavy
rainfall will be possible within any stronger rain shower and/or
thunderstorm. This would lead to minor/nuisance flooding concerns
across much of the Bay Area and Central Coast.

Beyond Thursday, there is uncertainty with the progression of the
upper level pattern. However, a general warming and drying trend
looks most likely as a shortwave ridge builds in wake of the exiting
trough.

&&

.AVIATION...
(00Z TAFS)
Issued at 410 PM PDT Sat Oct 11 2025

VFR throughout the region with some fair-weather cumulus across the
higher elevations and breezy and gusty northwesterly flow through
the evening hours. Winds become light overnight with low confidence
(around 20-30% probability) for fog impacts in the North Bay
valleys. Developing stratocumulus in the Santa Lucia range results
in a low confidence stratus impact for MRY overnight. Any developing
stratus and fog dissipates early Sunday morning with the breezy
northwest winds resuming in the afternoon.

Vicinity of SFO... High confidence of VFR through the TAF period.
Northwest winds gusting to 25 kt continue through the evening,
before resuming Sunday afternoon.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... High confidence of VFR through the TAF
period at SNS. Developing stratocumulus in the northern Santa Lucia
range may impact MRY overnight, but this is a low confidence
forecast (around 20% probability) and the TAF remains VFR
throughout. Breezy northwest winds continue through the evening
before resuming Sunday afternoon.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 410 PM PDT Sat Oct 11 2025

Increasing northerly winds continue to spread north over the
waters, resulting in hazardous conditions with locally stronger
winds and a Gale Warning along the Big Sur coastline. Occasional
gale force gusts are possible on Sunday across the northern
waters, and the windy pattern will persist into early next week.
The pattern for the first half week remains unsettled with more
wind and rain expected.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for SF Bay N of
     Bay Bridge.

     Small Craft Advisory until 3 AM PDT Sunday for Mry Bay.

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

     Gale Warning until 3 AM PDT Sunday for Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...DialH
MARINE...DialH

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