FXUS66 KMTR 231615
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
915 AM PDT Fri Oct 23 2026

...New UPDATE, MARINE...

.KEY MESSAGES...
Updated at 1231 AM PDT Fri Oct 23 2026

 - Gusty offshore flow across the North Bay Interior Mountains
   tonight through Saturday morning

 - Below normal temperatures today, increase to near normal for
   the weekend

 - Coastal Flooding due to full moon and thermal expansion this 
   weekend through at least the middle of next week

&&

.UPDATE...
Issued at 915 AM PDT Fri Oct 23 2026

Foggy conditions persist in the Russian River Valley and the 
Petaluma Valley in Sonoma County this morning where visibilities 
have been less than 1/4 mile at times. This fog is forecast to 
lift/mix out within the next couple of hours and give way to 
mostly sunny skies. Elsewhere, a mix of low to mid-level clouds 
persist as the trough responsible for the rain we have received 
over the past few days exits to the east. These clouds will exit 
the region as well and result in mostly sunny conditions this 
afternoon. As such, temperatures will warm to just below seasonal 
averages today and warm to near normal through the weekend as weak
ridging builds in from the eastern Pacific. A period of moderate 
to strong offshore winds are forecast late this evening and into 
Saturday morning across the North Bay Interior Mountains with 
weaker offshore flow in the higher elevations of the Bay Area. No 
updates to the ongoing forecast at this time. 

RGass

&&

.SHORT TERM...
Issued at 1231 AM PDT Fri Oct 23 2026
(Today and tonight)

The first rainfall event of the new water year is winding down, 
after bringing widespread beneficial wetting rainfall across our 
entire forecast area. Pockets of scattered light rain across the 
Central Coast remains possible through sunrise this morning. 
Lingering clouds and moisture will help keep temperatures below 
normal today before warming to near normal for the weekend. A 
developing burst of offshore flow will produce gusty winds across 
the North Bay Interior Mountains this evening through the morning 
hours Saturday as a relatively weak and progressive 'inside slider' 
trough passes south through the Central Valley today. A much drier 
airmass will build in behind the trough with PWATs falling from 
around 0.75" during the day today, to below 0.50" after sunset. The 
strongest wind gusts will occur above 2500ft, up to 45 MPH with 
little vertical gradient forcing to help translate stronger winds 
to lower lying areas.

&&

.LONG TERM...
Issued at 1231 AM PDT Fri Oct 23 2026
(Saturday through Thursday)

The weekend will see a return of temperatures to near normal for 
this time of year and bright sunny skies due to the drier airmass. 
Progressive low amplitude ridging this weekend will give way to an 
upper level low dropping south out of the PNW for the beginning of 
next week. Overall, consensus in the synoptic patter begins to 
diverge from there, but either way temperatures appear to remain 
right around normal with some pleasant Fall days through the 
extended forecast. Minor coastal flooding due to lunar phase and 
thermal expansion is possible at normal trouble spots.

&&

.AVIATION...
(12Z TAFS)
Issued at 417 AM PDT Fri Oct 23 2026

MVFR-IFR most sites with the exception of STS where fog and LIFR 
conditions have developed. Expect MVFR CIGs to persist through 
late morning with guidance showing clearing between 17-20Z. 
Persistent cloud cover should prevent fog from reaching APC this 
morning with moderate confidence that CIGs will stay on the
IFR/MVFR border. Moderate to high confidence in VFR conditions
this afternoon through the end of the TAF period as a much drier
air mass moves in in the wake of the departing upper level low.
Winds return to a more typical pattern with breezy onshore winds
during the afternoon/evening and lighter, variable to offshore
winds overnight.

Vicinity of SFO...MVFR CIGs persist through late morning with VFR
conditions/clear skies expected this afternoon through the end of
the TAF period. Moderate onshore winds peaking around 15 knots are
expected this afternoon before winds weaken overnight and
gradually become more easterly. 

SFO Bridge Approach...Patchy cloud cover may linger over the
southern SF Bay longer than over the SFO terminal this morning.
Guidance suggests it could take longer for cloud cover to clear
across the South Bay/Southern SF Bay as additional rounds of low
level clouds push in from the interior.

Monterey Bay Terminals...MVFR through late morning. Moderate
confidence that CIGs will clear around 19Z with VFR conditions to
prevail through the remainder of the day. Onshore winds to around
10-12 knots expected during the afternoon with lighter, variable
to offshore winds expected overnight.

&&

.MARINE...
(Today through Wednesday)
Issued at 915 AM PDT Fri Oct 23 2026

Conditions will continue to dry out this morning and be 
accompanied with fresh to locally strong northerly winds. Near 
gale force to gale force gusts possible across the far northern 
outer waters, with strong gusts south of Pigeon Point. Winds will 
gradually decrease through the day leading to moderate northerly 
breeze by Saturday morning and then prevailing through the 
upcoming week. Rough seas are expected today and tomorrow across 
the outer waters with wave heights peaking between 10 to 13 feet. 
Moderate seas prevail Sunday through much of next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
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 Pinos to Pt 
     Piedras Blancas 0-10 nm.

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

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt 
     to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Kennedy
MARINE...KR

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Prepared by Boulder-Creek.com Weather at: Fri Oct 23 10:30:03 PDT 2026