FXUS66 KMTR 270457
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
957 PM PDT Mon Oct 26 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 226 PM PDT Mon Oct 26 2026
- Coastal flooding at high tide by Bayshore and Pacific Coast
locations through the week. Worst flooding along bayshore Marin
County.
- Seasonally cool conditions this week
- Light rain possible Friday into the weekend
&&
.SHORT TERM...
Issued at 226 PM PDT Mon Oct 26 2026
(This evening through Tuesday night)
Seasonal to seasonally cool temperatures continue through the
upcoming week as upper level troughing lingers over the West Coast.
Overnight temperatures will also be on the cooler side with morning
lows dropping into the 40s to upper 30s across the region. In the
Short Term, expect more classic fall weather to continue with
gustier onshore winds in the afternoon/evening. Stronger winds peak
between 25 to 30 mph along the coast and across mountain gaps/passes
(Altamont Pass, Salinas Valley, San Bruno Gap - to name a few).
Winds ease overnight but expect another round of gusty onshore winds
during the afternoon/evening on Tuesday.
The main hazard Monday/Tuesday continues to be the threat for
coastal flooding along the San Francisco/San Pablo Bay shorelines
and along the Pacific Coast. This coastal flood event is brought to
you by a combination of the full moon (10/26) and thermal expansion
due to warmer ocean temperatures on top of our typical tidal
pattern. High tides peak today and tomorrow with up to 2.1 ft of
inundation above ground level expected. The strongest impacts will
be felt along low-lying portions of bayshore Marin County where
numerous flooding reports have already been received. If you live in
a low-lying area prone to flooding along the bay or Pacific Coast,
make sure to have all flood preparations in place before high tide
tomorrow (12:15 PM). If you encounter a flooded road, turn around
don't drown. You don't know how deep flood waters are, how fast a
current may be, or if the road is structurally sound beneath the
water. Coastal flooding is set to peak on Tuesday with tidal heights
dropping throughout the long term (for more in depth discussion see
the Long Term forecast).
&&
.LONG TERM...
Issued at 226 PM PDT Mon Oct 26 2026
(Wednesday through next Sunday)
Troughing generally persists through the upcoming week with a deeper
upper level low arriving Friday into the weekend. Seasonal to
seasonally cool temperatures continue through the extended forecast
but expect temperatures to drop another couple of degrees Friday
into the weekend. Diurnally gusty winds continue for favored
locations this week with stronger gusts during the afternoon/evening
along the coast and across mountain gaps/passes. High temperatures
Wednesday and Thursday will be in the mid to upper 60s across the
interior while coastal areas linger in the upper 50s to low 60s.
Friday we see the promised further cooldown with interior lows
dropping into the low 60s and most coastal areas lingering in the
mid to upper 50s. Cooler temperatures remain in place through the
end of the weekend. Expect overnight cloud cover to return by
midweek with cloudy skies becoming more predominant Thursday into
the weekend as the deeper trough arrives. Light rain remains
possible Friday into the weekend but, fortunately, the bulk of the
rain has shifted southwards towards Southern California. That's not
to say we will be completely dry this weekend. Expect drizzly
conditions across the Bay Area Saturday into Sunday with light rain
possible overnight heading into Sunday. Light rain is expected
across the Central Coast but totals should be fairly light across
urban areas (around a tenth of an inch). For the higher elevations
of the Santa Lucia Range and the Gabilan Range, light rain amounting
to a couple tenths of an inch is possible. All together, the classic
fall weather should lend itself a ghostly ambiance for anyone
partaking in any haunted/spooktacular activities this weekend.
Coastal flooding concerns continue across Bayshore locations within
the San Pablo, San Francisco, and Monterey Bays and the Pacific
coastal regions through at least Thursday. While tidal heights peak
Tuesday, heights will remain elevated through late week. At the San
Francisco tidal gauge, high tide is expected to be 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.
Currently, tidal heights continue to run above the forecast with the
forecast heights for Monday/Tuesday being increased. If this trend
continues into mid to late week we may see coastal flooding concerns
extended Friday into the weekend (necessitating the extension of the
product). Expect the worst flooding to continue in low-lying
bayshore locations of Marin County.
&&
.AVIATION...
(06Z TAFS)
Issued at 957 PM PDT Mon Oct 26 2026
3.2 mb ACV-SFO and 1.5 mb SFO-SAC pressure gradients support
northwesterly winds, dry conditions and a few areas of low clouds
/VFR-MVFR/. Cool air advection is occurring from the surface up
through 850 mb (~ 5,000 feet); 925 mb and 850 mb temperatures were
in the 25th percentile for late October on the evening Oakland
upper air sounding. In contrast to this, sea surface temperatures
in the 60s are much above October normals by 5.5F to almost 9F.
Monterey bay buoy sea surface temp 67F to 68F earlier today is the
warmest this late in the season for the period of record (NDBC
data for Monterey buoy 1987-2023).
Back to the 00z Oakland sounding, there is a weak temperature
inversion based at 5000 feet with a fair amount of vertical mixing
from the surface to this altitude that'll carry over tonight over
the coastal waters. Current surface weather observations are mainly
VFR-MVFR. At the air/sea interface heat flow and water vapor are
upward directed, with upslope winds and radiative cooling expect
ongoing areas of low clouds /VFR-MVFR/ tonight and Tuesday morning.
Over land where surface winds become light and there is no marine
influence and temperatures cool, a few patches of valley fog /IFR-
LIFR/ may develop. Otherwise it'll be VFR Tuesday.
Vicinity of SFO...VFR. West wind 10 to 12 knots tonight and
Tuesday morning. West wind increasing to 15 to 25 knots Tuesday
afternoon to mid evening.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Areas low clouds /VFR-MVFR/ tonight and
Tuesday morning. Winds light and variable tonight and Tuesday
morning. West to northwest winds 10 to 15 knots Tuesday afternoon
and early evening.
&&
.MARINE...
(Tonight through next Sunday)
Issued at 848 PM PDT Mon Oct 26 2026
Moderate to fresh north to northwesterly will prevail through the
majority of the week. Strong gusts will continue to develop
tonight 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 tomorrow. 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 5 PM PDT Friday for CAZ006-505-506-
508-509-529-530.
PZ...Small Craft Advisory from 3 AM to 9 PM PDT Tuesday for Pt Arena
to Pt Reyes 0-10 nm.
Small Craft Advisory until 3 AM PDT Tuesday for Pigeon Pt to Pt
Pinos 0-10 nm.
Small Craft Advisory until 9 PM PDT Tuesday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Small Craft Advisory from 3 AM Tuesday to 9 AM PDT Wednesday for
Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 9 AM Tuesday to 9 AM PDT Wednesday for
Pigeon Pt to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Mon Oct 26 22:30:03 PDT 2026
From the National Weather Service
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