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
From the National Weather Service
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