286
FXUS66 KMTR 261156
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
456 AM PDT Mon Oct 26 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1201 AM PDT Mon Oct 26 2026

 - Minor coastal flooding at high tide for Bayshore and Pacific
   Coast locations through the week

 - Cool conditions through the week

 - Rain chances late week into the upcoming weekend

&&

.SHORT TERM...
Issued at 1201 AM PDT Mon Oct 26 2026
(Today and tonight)

Satellite imagery shows mostly clear conditions with patches of
stratus developing on the west side of the San Mateo Peninsula, the
Berkeley-San Leandro Hills, and the Chittenden Pass between
Watsonville and Hollister. High resolution model output depicts more
widespread stratus coverage through the morning, but confidence is
limited as the model output is a lot more aggressive in terms of
stratus coverage than the observations suggest. In any case, stratus
should dissipate through the morning and afternoon hours with
generally clear skies into the evening.

Cooler conditions are in store for today as the shortwave ridge
moves off to the east and allows a cut-off low to move into the
Pacific Northwest. This low is bringing wet weather into the Pacific
Northwest and the North Coast, but down in the Bay Area the main
impacts will be cooler temperatures with highs reaching the middle
60s to lower 70s in the inland valleys and close to the Bays, up to
the middle 70s in the warmest spots of southern Monterey County, and
the upper 50s to lower 60s along the Pacific coast. Onshore winds
will pick up this afternoon and evening with gusts to 25 mph along
the coast, through favored gaps and passes, and at the ridgelines.
Expect gusts in these areas to remain elevated through the night as
the passing low creates an elevated pressure gradient.

A combination of high astronomical tides and surge from thermal
expansion effects brings the risk of minor coastal flooding along
the Bayshore at the San Pablo, San Francisco, and Monterey Bays, and
the Pacific coast, at high tide today. At the San Francisco tidal
gauge, high tide is expected to be 1.6 ft above normal (7.4 ft MLLW)
at 11:39 AM Monday 10/26, including around 1.0 ft of surge residual
partially attributed to impacts from El Nino.

&&

.LONG TERM...
Issued at 1201 AM PDT Mon Oct 26 2026
(Tuesday through Sunday)

Troughing will continue to impact the region through the seven day
outlook. By Tuesday, a shortwave trough currently over southeastern
Alaska will dig down and bring more troughing influence over the
region, while a second cut-off low forms over western Canada and
migrates southward through Wednesday to reinforce the troughing
pattern. Over the same timeframe, a low pressure system over the
central Pacific migrates eastwards and merges with the trough over
the Pacific Northwest, furthering the influence of the trough across
the state. The net result will be a continued gradual cooling trend
across the region with highs dipping into the middle 50s to middle
60s across the lower elevations by the latter part of the week.

Ensemble model cluster analysis is beginning to agree on some form
of troughing pattern persisting into the upcoming weekend with rain
chances entering the picture Friday night. Confidence in rainfall in
the North Bay for Halloween has decreased, but remains low to
moderate south of the Golden Gate and might slightly higher in the
Central Coast, although it looks like the current forecast favors
most of the moisture coming into Southern California. This makes for
a difficult forecast situation, as the fringes of a moisture plume
can make for some highly defined gradients where shifts of the
forecast track on the order of 10 miles can significantly impact
the final outcome. To give one example of the kind of variability
we are talking about here, let`s look at the current rainfall
forecasts for the Monterey Airport. NBM guidance suggests that for
the 48hour period beginning 5 AM PDT Saturday the 31st and ending
4 AM PST Monday the 2nd (note the time change, as this period
includes the "fall back" from Daylight Savings Time), there is a
50% probability that the rainfall total falls between 0.0 and 0.6
inches, and an 80% probability that the total falls between 0.0
and 1.6 inches. It`s too early to say at this point whether
people`s Halloween plans will need to take rain into account, so
keep checking back for forecast updates. If that wasn`t enough,
ensemble model output and long range outlooks suggest that an
active pattern could remain in store for the first week of
November...

Coastal flooding concerns continue across Bayshore locations within
the San Pablo, San Francisco, and Monterey Bays and the Pacific
coastal regions through Friday. At the San Francisco tidal gauge,
high tide is expected to be 1.8 ft above normal (7.6 ft MLLW) at
12:15 PM Tuesday 10/27, 1.9 ft above normal (7.7 ft MLLW) at 12:56
PM Wednesday 10/28, 1.7 ft above normal (7.5 ft MLLW) at 01:43 PM
Thursday 10/29, 1.4 ft above normal (7.2 ft MLLW) at 2:39 PM on
Friday 10/30, and 1.0 feet above normal (6.8 ft MLLW) at 3:44 PM on
Saturday 10/31, including around 1.0 ft of surge residual partially
attributed to impacts from El Nino.

&&

.AVIATION...
(12Z TAFS)
Issued at 455 AM PDT Mon Oct 26 2026

A mix of MVFR to IFR ceilings are present at a few airports.
Ceilings are expected to mix out post sunrise with VFR prevailing
through the day. As a cold front pushes through the Pacific
Northwest, strong onshore winds develop this afternoon into the
evening. Most terminals may experience occasional gusts around 10-15
kt. Moderate confidence for more frequent gusts at STS, SFO, HAF,
and MRY. Currently not expecting a robust development of impactful
low clouds later this evening as we transition into a zonal flow
aloft. Onshore winds persist through the overnight hours.

Vicinity of SFO...VFR with a few to scattered MVFR cloud decks
likely. Wind direction is unfavorable for impactful ceilings to
develop directly over SFO and OAK in the next few hours. Mostly
clear skies through the afternoon with strong gusts possible at SFO.
Onshore winds gradually ease post-sunset.

SFO Bridge Approach...MVFR ceilings on the eastern portion of the
approach may impact visuals. VFR conditions expected post-sunrise as
clouds scatter out. Otherwise, similar to SFO.

Monterey Bay Terminals...MVFR ceilings persist at SNS through the
morning. Low confidence on MVFR ceilings at MRY this morning. VFR
prevails through the remainder of the TAF period with gusty onshore
winds this afternoon.

&&

.MARINE...
(Today through Saturday)
Issued at 455 AM PDT Mon Oct 26 2026

North to northwesterly gentle breezes become moderate to fresh
this  afternoon through the majority of the week. Strong gusts
develop  this afternoon across the southern coastal waters near
Point Sur and  Monterey Bay. These strong gusts gradually spread
across the  northern coastal waters near Point Reyes by Tuesday.
Isolated near  gale force gusts are likely within the coastal jet
regions of Point  Sur and Point Reyes. In response, moderate seas
briefly build to  rough around 8 to 10 ft across the outer waters
Tuesday afternoon  into Wednesday. Moderate wind driven seas
prevail Thursday into the  weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 3 PM PDT Thursday for CAZ006-506-
     508-529-530.

     Coastal Flood Advisory from 9 AM this morning to 3 PM PDT
     Thursday for CAZ505-509.

PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for Mry Bay.

     Small Craft Advisory from 3 AM to 9 PM PDT Tuesday for Pt Arena
     to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory from 3 PM this afternoon to 3 AM PDT
     Tuesday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

     Small Craft Advisory from 9 AM to 9 PM PDT Tuesday for Pigeon Pt
     to Pt Pinos 10-60 NM.

&&

$$

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

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