FXUS66 KMTR 130523
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1023 PM PDT Sat Sep 12 2026

...New SHORT TERM, LONG TERM, AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1022 PM PDT Sat Sep 12 2026

 - Breezy onshore winds persist through Sunday afternoon

 - Temperatures near seasonal averages through the upcoming week

 - Dry offshore winds for the higher terrain Sunday night into
   Monday night

&&

.SHORT TERM...
Issued at 1022 PM PDT Sat Sep 12 2026
(Tonight through Sunday)

Skies are generally clear, save for the Pacific coast of San Mateo 
County where some low clouds have developed overnight, and will 
generally remain so through the day on Sunday. There is a low 
confidence of stratus development near the northern end of the Santa 
Lucias that could impact the southern Monterey Bay region early 
Sunday morning, but if this develops it should mix out soon after 
dawn.

The weather pattern remains dominated by a cutoff low coming into 
Oregon, which interacts with a broad area of zonal flow and slight 
ridging across the Southwest to create a strong pressure gradient 
over the northern half of California and Nevada. At 9 PM the SFO-WMC 
gradient was measured at 9.7 mb, and there are still a couple of 
hours where the gradient could strengthen further before the cutoff 
low's motion starts to relax the gradient. Wind gusts across the 
region have peaked at around 20 to 35 mph, with the most favored 
locations seeing wind gusts of over 50 mph. This is expected to 
continue well into the night, with some abatement in the early 
morning hours on Sunday. By the time the sea breeze kicks in Sunday 
afternoon, the pressure gradients will relax, but remain rather 
strong and some elevated winds are still possible before the winds 
finally turn light in the late evening hours. Widespread gusts will 
likely reach 20 to 30 mph with favored locations along the coast and 
through gaps, passes, and valleys reaching 40 mph.

Morning lows will generally hover in the upper 40s to the 50s 
across the region. Sunday's highs range from the middle 70s to the
lower 80s inland, the middle 80s in the warmest reaches of 
southern Monterey County, the middle 60s to the middle 70s near 
the Bays, and the lower to middle 60s close to the Pacific coast.

&&

.LONG TERM...
Issued at 1022 PM PDT Sat Sep 12 2026
(Monday through next Saturday)

The trough axis continues moving into the northern Plains by Monday, 
relaxing the pressure gradients and diminishing the potential for 
strong winds. Some troughing influence will remain along the West 
Coast through at least the middle of the week and there may even be 
a pulse of energy coming off the back of the first trough that would 
reinforce the pattern, keeping temperatures near to below seasonal 
averages. High temperatures will range across the 80s inland, the 
lower 70s to the lower 80s close to the bays, and the middle 60s to 
the lower 70s near the Pacific coast. The widespread marine layer 
stratus deck should return Monday night into Tuesday, and will 
develop each night and morning before mixing out through the 
afternoon hours. Friday into the upcoming weekend, model ensembles 
are showing a chance for some sort of ridge influence across the 
region, thus reflecting the probability for a slight warming
trend. 

&&

.AVIATION...
(06Z TAFS)
Issued at 1022 PM PDT Sat Sep 12 2026

Generally VFR conditions persist through the TAF period, barring the 
immediate coast and some favored foothill regions where MVFR-IFR 
stratus has set up on the western side of the San Mateo Peninsula
and the hills east of HWD, persisting into the morning hours. 
Strong and gusty onshore winds continue well into the night, with 
some abatement in wind speeds Sunday morning before winds tick up 
again Sunday afternoon into the evening hours, when winds will 
begin to diminish. 

Vicinity of SFO... High confidence that VFR conditions persist 
through the TAF period. Strong west to northwest winds gusting to 35 
kt will continue past midnight, with a slight decrease in wind 
speeds early Sunday morning before the strong gusts resume Sunday 
afternoon and evening. 

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR through midnight, low to moderate 
confidence in patchy MVFR stratus in the pre-dawn hours of Sunday 
morning. Gentle west winds will persist overnight through Sunday 
morning before strong and gusty northwest winds resume on Sunday 
afternoon.

&&

.MARINE...
(Tonight through next Friday)
Issued at 1022 PM PDT Sat Sep 12 2026

Hazardous conditions for small craft prevail through the middle of
next week. Fresh to strong winds gradually increase through the
night with widespread strong winds developing through Sunday.
Widespread near gale force gusts are likely Sunday into early
Monday with gale force gusts expected along the inner waters from
Pigeon Point to Point Piedras Blancas, the Monterey Bay, and in
portions of the San Francisco and San Pablo Bays where terrain
promotes wind funneling. Winds remain elevated through midweek
before decreasing mid to late week. Moderate seas will build to
between 8 to 10 feet and become rough by Monday in response to the
stronger winds.

&&

.FIRE WEATHER...
Issued at 1201 PM PDT Sat Sep 12 2026

The marine layer was around 1,500 feet in depth per 12Z OAK Upper
Air Sounding. However, stratus coverage did not match the typical
depth this morning and is not likely to again tonight despite the
marine layer forecast to be between 1,500-2,000 feet. A dry 
frontal boundary is forecast to move across the Central Coast 
tonight and into Sunday morning. Ahead of this boundary, we are 
expecting an increase in 925 mb relative humidities which would 
lead to higher humidity over the Timber and Plaskett fires 
overnight and into Sunday morning. Sunday night into Monday night,
a light to gentle offshore breeze (with occasionally moderate 
gusts) is forecast to develop in the higher terrain as the 
mid/upper level trough axis shifts into the northern Rockies. As 
such, areas above the marine layer often experience nocturnal 
drying that will likely continue through early this upcoming week.

RGass

&&

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

     Small Craft Advisory from 3 PM to 9 PM PDT Sunday for SF Bay N 
     of Bay Bridge.

     Small Craft Advisory until 3 PM PDT Sunday for Mry Bay-Pigeon Pt 
     to Pt Pinos 0-10 nm.

     Gale Warning from 3 PM to 9 PM PDT Sunday for Mry Bay-Pigeon Pt 
     to Pt Pinos 0-10 nm.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt 
     Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Gale Warning until 9 PM PDT Sunday for Pt Pinos to Pt Piedras 
     Blancas 0-10 nm.

     Small Craft Advisory from 3 PM Sunday to 9 AM PDT Monday for Pt 
     Arena to Pt Reyes 10-60 NM.

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

&&

$$

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

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Prepared by Boulder-Creek.com Weather at: Sun Sep 13 04:30:04 PDT 2026