638
FXUS66 KMTR 312333
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
433 PM PDT Sat Oct 31 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1129 AM PDT Sat Oct 31 2026

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

 - Seasonal to slightly below seasonal temperatures through Thursday

 - Potential for light rain Saturday night and again early in the
   upcoming week

&&

.SHORT TERM...
Issued at 1129 AM PDT Sat Oct 31 2026
(This afternoon through Sunday)

Chances for rain showers remain greatest (20-50%) across the
mountains of San Bentio County and interior portions of Monterey
County through the rest of the day today. This is all head of a
cold front that will approach from the northwest and move
southeastward across the North Bay late this evening (between 7 -
11 PM PDT), across the rest of the Bay Area (between 11 PM PDT - 6
AM Sunday PST), and across the Central Coast (between 1 - 7 AM
Sunday PST). As the front moves through the region overnight,
there is a 10-20% probability of thunderstorms, largely over the
coastal waters. Post frontal rain showers may linger offshore and
along the Monterey County coastline through early Sunday
afternoon. All in all, rainfall amounts are forecast to be on the
light side through Sunday afternoon with the greatest probability
of measuring >0.25" being in the coastal ranges and lesser amounts
as you move farther inland.

By Sunday afternoon, expect mostly dry and clearing sky
conditions as weak ridging builds in from the eastern Pacific in
wake of the exiting trough. Temperatures will remain seasonably
cool with afternoon highs in the 60s and overnight lows in the 40s
to lower 50s with the coldest regions of the North Bay
potentially reaching into the upper 30s both tonight and Sunday
night. Again, coastal flooding remains possible along the bayshore
locations of the San Francisco, San Pablo, and Monterey Bays
through Sunday at 6 PM PST with the Pacific Coast dropping off at
6 PM PDT this evening. For more information on that please see the
CFWMTR product.

&&

.LONG TERM...
Issued at 1129 AM PDT Sat Oct 31 2026
(Sunday night through next Friday)

The next chance for rain across the region will be from early
Tuesday morning through Wednesday morning as an upper level cut-
off low approaches the northern California coast from the west.
But again, not expecting widespread heavy rainfall from this
system. The placement of the cut-off low remains in question from
Monday night through Wednesday. A farther north track would result
in less rainfall across the Bay Area and Central Coast vs. a more
southern track. Dry weather now looks to return for the remainder
of next week with a gradual warming trend heading into next
weekend.

&&

.AVIATION...
(00Z TAFS)
Issued at 432 PM PDT Sat Oct 31 2026

Breezy onshore winds prevail this afternoon with VFR ceilings.
Winds ease slightly through the evening ahead of an approaching
frontal boundary that will move across the North Bay and the Bay
Area between 06-08Z and then the South Bay, East Bay, and Monterey
Bay Terminals between 08-10Z. Keeping VFR conditions through the
TAF period, with periods of VFR-MVFR ceilings as the rain showers
move over the terminals. In wake of the frontal passage, clearing
skies are forecast with an increase in northwesterly winds by
Sunday afternoon and early evening.

Vicinity of SFO...VFR. Onshore winds are forecast to ease late
this evening ahead of rain showers forecast to arrive between
06-08Z with SCT MVFR ceilings. Northwesterly winds are forecast to
increase in wake of the frontal passage with clearing skies.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Onshore winds are forecast to ease
this evening. Rain showers will arrive ahead of a frontal boundary
by around 09Z Sunday and begin to tapper off by 15Z, with periods
of VFR-MVFR ceilings as the rain showers move over the terminals.
Onshore winds and clearing skies are forecast in wake of the
frontal passage.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 432 PM PDT Sat Oct 31 2026

Through the weekend northwest breezes remain gentle to moderate,
becoming variable overnight, as moderate seas persist into early
next week. By mid-week, northwest winds increase to fresh with
building rough seas across the outer waters. Light rain showers
are possible tonight through Sunday morning with potentially more
to come Tuesday into Wednesday. A long period southerly swell
remains this weekend and combines with a long period northwesterly
swell on Monday.

&&

.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 this evening for CAZ505-
     509.

PZ...None.
&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...RGass
MARINE...Navarrete

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