FXUS66 KMTR 281810
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1110 AM PDT Wed Oct 28 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1227 AM PDT Wed Oct 28 2026

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

 - Seasonal to slightly below seasonal temperatures through the
   extended forecast

 - Potential for rain this weekend and again early to mid next
   week

&&

.SHORT TERM...
Issued at 1227 AM PDT Wed Oct 28 2026
(Today and tonight)

Satellite imagery shows lingering high clouds over Monterey and 
San Benito Counties with patches of stratus along parts of the 
higher elevations. Some stratus expansion is possible through the 
morning with some clearing after sunrise, but high level clouds 
will also arrive this morning and persist into the evening hours 
and beyond. 

Conditions remain cool and dry as large scale troughing persists and 
expands, with a cut-off low over British Columbia and a decaying low 
crossing over from the Central Pacific merging to help dig the 
trough axis deeper into California. Morning lows hover in the upper 
30s to the middle 40s across the inland valleys, into the middle 30s 
for the coldest spots in the eastern Santa Clara and interior 
Central Coast mountains, and the upper 40s to lower 50s near the 
coasts. Highs will remain cooler than the seasonal averages with 
high temperatures in the upper 60s to lower 70s inland, the middle 
60s to near 70 along the Bayshore, and the upper 50s to lower 60s at 
the immediate coast. Winds will remain relatively light with a 
gentle onshore push expected in the afternoon and evening hours. 
Wind gusts might reach 20 mph along favored coastal areas and 
through favored gaps and passes.

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 1.9 ft above normal (7.7 ft MLLW) 
at 12:56 PM Wednesday 10/28, including around 1.2 ft of surge 
residual partially attributed to impacts from El Nino.

&&

.LONG TERM...
Issued at 1227 AM PDT Wed Oct 28 2026
(Thursday through Tuesday)

Troughing will continue to impact the region at least into the 
upcoming weekend, with high temperatures dipping into the middle 60s 
to lower 70s inland and the upper 50s to lower 60s near the Pacific 
coast and the Bays. Gloomy and cloudy conditions continue into 
Friday. The chances for rain continue to be rather low during the 
Halloween weekend, with probabilities of precipitation around 10 to 
30% throughout the Bay Area and Central Coast. Rainfall totals, 
assuming rain does come, will remain on the beneficial side with the 
latest forecast showing a few hundredths of an inch across the 
southern halves of Monterey and San Benito Counties and zero 
accumulating precipitation everywhere else. Even the reasonable 
worst case scenario, one with a 10% probability that rain totals 
will end up above the scenario, ranges from around a tenth of an 
inch in the North bay to a half to three quarters of an inch for 
interior Monterey and San Benito Counties. 

Once we cross into the early part of next week, the meteorological 
uncertainty really ratchets upwards. The current forecast shows 
chances for rain continuing into the end of the 7-day outlook, but 
merely looking at some of the models, say, the deterministic 
European model or the European ensemble mean, would leave the 
untrained user scratching their heads trying to reconcile that 
forecast with the ridge that these models depict over the West 
Coast. Setting aside the fact that this is where the model 
reliability begins to degrade, especially for the deterministic 
models, there are a few things that are going on here. The first is 
that the deterministic models are depicting the formation of a cut-
off low in the central Pacific, and cut-off lows are notoriously 
difficult to accurately predict as they can isolate themselves from 
the large-scale flow. Indeed, the American GFS model depicts this 
cut-off low coming closer to the state around this time. Looking at 
ensemble model cluster analysis will support the high uncertainty as 
there's not really a dominant scenario out of various solutions on 
how fast the cut-off low will come into the Western United States, 
and indeed it looks like the speed of the low is the main factor in 
creating the uncertain ensemble space. Or in layman's terms, there 
are chances for rain next week, but when the rain actually arrives 
is up in the question, and that is before we try to find out where 
in the state the rain will actually be the heaviest. Keep checking 
back with us for more details...

Coastal flooding concerns continue across Bayshore locations within 
the San Pablo, San Francisco, and Monterey Bays through Saturday 
and the Pacific coastal regions through Friday. At the San 
Francisco tidal gauge, high tide is expected to be 1.9 ft above 
normal (7.7 ft MLLW) at 01:43 PM Thursday 10/29, 1.6 ft above 
normal (7.4 ft MLLW) at 02:39 PM Friday 10/30, and 1.1 feet above 
normal (6.9 ft MLLW) at 03:44 PM on Saturday 10/31, including 
around 1.2 ft of surge residual partially attributed to impacts 
from El Nino.

&&

.AVIATION...
(18Z TAFS)
Issued at 1108 AM PDT Wed Oct 28 2026

High clouds will continue to stream across the region today and into 
Thursday morning, yet VFR conditions are forecast to prevail through 
the TAF period.

Vicinity of SFO...VFR through the TAF period. Light and variable 
winds are forecast to persist through about 21Z and become westerly 
this afternoon and evening. Winds ease late in the night and become 
variable into Thursday morning. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. West to 
northwesterly winds will increase this afternoon and become light 
and variable overnight and into Thursday morning.  

&&

.MARINE...
(Today through Monday)
Issued at 1108 AM PDT Wed Oct 28 2026

Moderate to strong northwest winds continue today across the outer
waters with fresh to moderate breezes along coastal waters, with
seas continuing to build in response and resulting in rough seas
over exposed waters. Expect gradually improving conditions by
Thursday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 6 PM PDT Saturday for CAZ006-506-
     508-529-530.

     Coastal Flood Advisory until 5 PM PDT Friday for CAZ505-509.

PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this 
     evening for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt 
     Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 PM PDT Thursday for Pt Arena to Pt 
     Reyes 10-60 NM.

     Small Craft Advisory until 3 PM PDT Thursday for Pigeon Pt to Pt 
     Pinos 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...RGass
MARINE...RGass

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Prepared by Boulder-Creek.com Weather at: Wed Oct 28 14:30:03 PDT 2026