FXUS66 KMTR 260702
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1202 AM PDT Mon Oct 26 2026
...New SHORT TERM, LONG TERM...
.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...
(06Z TAFS)
Issued at 937 PM PDT Sun Oct 25 2026
High clouds will steadily clear out to the east tonight. Patchy
low clouds /MVFR-IFR/ are developing over the coastal waters and
along the coastline. Nocturnal radiative cooling will strengthen
and combine with surface to lower level convergence out ahead of a
weak cool front moving in from the northwest, the front arrives
Monday.
The potential is there for ongoing low cloud /MVFR-IFR/ development
tonight and Monday morning. Diurnal warming and mixing will result
in mainly VFR across the forecast area late Monday morning and
afternoon.
Vicinity of SFO...VFR with a west wind diminishing tonight and
Monday morning. Low confidence forecast for tempo low clouds /MVFR/
08z-12z then prevailing MVFR to 19z Monday. West wind increasing
to 15 to 25 knots Monday afternoon to mid evening.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Low clouds /MVFR-IFR/ developing tonight
and Monday morning ahead of a weak cool front arriving from the
northwest on Monday. VFR is forecast late morning and afternoon
Monday, VFR possibly extending into Monday evening. Winds light
and variable tonight and Monday morning, then west to northwest 10
knots late Monday morning through early evening.
&&
.MARINE...
(Tonight through next Saturday)
Issued at 919 PM PDT Sun Oct 25 2026
Gentle north to northwest breezes will become moderate to fresh
early this week. Strong gusts increase across the southern coastal
waters near Point Sur and Monterey Bay by Monday afternoon, with
some isolated near gale force gusts. Moderate seas of 4 to 5 ft
continue for offshore waters, but will build to 6 to 8 ft seas
Monday into Tuesday. Slight seas of 2 to 4 ft hold the immediate
coastline and build to moderate 4 to 6 ft for Monday.
&&
.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 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.
&&
$$
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Mon Oct 26 04:30:03 PDT 2026
From the National Weather Service
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