FXUS66 KMTR 310432
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
932 PM PDT Fri Oct 30 2026
...New UPDATE, MARINE...
.KEY MESSAGES...
Updated at 1213 PM PDT Fri Oct 30 2026
- Minor to moderate coastal flooding at high tide for Bayshore
and Pacific Coast locations through the weekend
- Seasonal to slightly below seasonal temperatures through the
extended forecast
- Potential for rain Saturday and again next week
&&
.UPDATE...
Issued at 913 PM PDT Fri Oct 30 2026
Weather item of note during the evening hours has been ongoing
shower activity over the Southern Diablo Range. Shortly after peak
heating of the day cells began to pop over the interior mts of the
Central Coast. Instability, daytime heating, and some topographic
enhancement led to a few showers. As these showers drifted
eastward into the Central Valley they tapped into more
instability, which led to showers becoming thunderstorms. Will
keep KMUX in precip early tonight as it is still tracking the
diminishing cells drifting eastward. Rainfall amounts were
generally light with the Santa Rita Peak RAWS tipping .06".
Elsewhere, pretty quiet weather this evening with mid-high level
clouds drifting overhead.
Next up will be fine tuning the Halloween forecast.
MM
&&
.SHORT TERM...
Issued at 1213 PM PDT Fri Oct 30 2026
(This evening through Sunday)
There remains a slight chance to chance for rain showers across the
Central Coast (mainly across interior Monterey County and San Benito
County) through this evening. There is also a 5-10% probability of
thunderstorms this afternoon and early evening across the mountains
of San Benito County, however probabilities remain low at this time.
The primary hazards with any isolated thunderstorms that do develop
will be lightning, localized moderate/heavy downpours, and
gusty/erratic winds.
Tonight, mostly dry conditions are forecast to persist as the cold
front pushes into northern California and weakens as at approaches
the Bay Area. This feature will bring chances for rain across the
Bay Area by Saturday afternoon and into early Sunday morning.
Meanwhile, chances for precipitation across the Central Coast from
remnant moisture aimed toward southern California.
All that said, the NBM Probabilities of reaching greater than 0.25"
(15-35%) reamin highest along the highest through tonight across
Monterey and San Bentio. Then by Saturday night across Sonoma County
and 15-45% across Monterey and San Benito counties Saturday night
into Sunday morning.
From previous forecaster: "A combination of high astronomical tides
and surge from thermal expansion and low pressure 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 1.9 ft above normal (7.7 ft MLLW) at 2:39 PM today, 1.5 ft
above normal (7.3 ft MLLW) at 3:44 PM Saturday, and 1.0 feet above
normal (6.8 ft MLLW) at 3:59 PM Sunday, including around 1.5 ft of
surge residual." The Coastal Flood Advisory drops off after high
tide on Saturday for the Pacific Coast but remains in effect through
Sunday for bayshore locations along the San Pablo, San Francisco,
and Monterey Bays.
&&
.LONG TERM...
Issued at 1213 PM PDT Fri Oct 30 2026
(Sunday night through next Thursday)
Weak ridging builds in from the eastern Pacific Sunday and into
Monday in wake of the exiting trough. This will result clearing of
clouds regionwide and dry weather conditions Sunday afternoon
through Monday afternoon along with a slight warming trend. However,
temperatures will generally remain a few degrees below normal.
Tuesday and beyond, there is still a great amount of uncertainty
with the forecast. The current forecast indicates a slight chance of
rain/rain showers on Tuesday as a trough or cut-off low approaches
the Bay Area and Central Coast. That said, the Climate Prediction
Center's 6-10 Day Outlook our region in the 33-40% for greater than
normal precipitation.
&&
.AVIATION...
(00Z TAFS)
Issued at 450 PM PDT Fri Oct 30 2026
VFR prevails with light rain chances likely in the following TAF
issuance (after 06Z) for coastal sites. A mix of high to mid-level
clouds persist through the day, which gradually lower towards the
end of the TAF cycle. Greater chance for borderline MVFR-VFR
ceilings at the Monterey Bay terminals tonight. Onshore breezes
around 10-15 kt become light south to southwesterly through the
overnight hours, and increase again Saturday.
Vicinity of SFO...VFR. Moderate westerly breezes gradually ease
before increasing again Saturday morning. Light rain showers may
develop as early as Saturday evening around 7-8 PM PDT (02-03Z),
though chances increase after 11 PM PDT (06Z). Lower cloud bases are
anticipated with the increasing chances of rain, but are expected to
remain VFR or borderline VFR-MVFR.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR with brief periods of MVFR-VFR ceilings
continue through the afternoon. Onshore winds become gentle
southerly breezes overnight. Low confidence on light drizzle
occuring overnight. Westerly winds around 8-10 kt increase again by
late Saturday morning.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 913 PM PDT Fri Oct 30 2026
Gentle to fresh northerly breezes prevail over the coastal waters
as a weak cold front approaches from the north. These conditions
will persist with moderate seas into early next week. Mid-week,
wind driven seas build to rough across the outer waters. A long
period southwesterly swell persists through the weekend and
combines with a long period northwest swell early next week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 6 PM PDT Sunday for CAZ006-506-508-
529-530.
Coastal Flood Advisory until 6 PM PDT Saturday for CAZ505-509.
PZ...None.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Navarrete
MARINE...MM
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Prepared by Boulder-Creek.com Weather at: Fri Oct 30 22:30:03 PDT 2026
From the National Weather Service
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