340
FXUS66 KMTR 231609
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
909 AM PDT Thu Jul 23 2026

...New UPDATE, MARINE...

.KEY MESSAGES...
Updated at 1234 PM PDT Wed Jul 22 2026

 - Breezy onshore winds return late this week and into the
   weekend

 - Temperatures near seasonal averages throughout early next week

&&

.UPDATE...
Issued at 908 AM PDT Thu Jul 23 2026

The stratus pattern was more typical for this time of year and was
able to spread into the inland valleys overnight. However, dry air
aloft was able to disrupt the cloud deck across the Monterey Bay
region. We also had fog in places like Russian River Valley, Santa
Rosa, Half Moon Bay, Marina, and Monterey at times this morning.
However, conditions continue to improve across much of the region as
low clouds retreat back to the coast. No significant updates needed
to the ongoing forecast at this time. More on the Beach Hazards
Statement with the afternoon update.

RGass

&&

.SHORT TERM...
Issued at 1245 AM PDT Thu Jul 23 2026
(Today and tonight)

Patchy coastal low clouds are trying to redevelop early this
morning. Higher dewpoint air lingers, however areal low cloud
coverage will depend on the total amount of nocturnal radiative
cooling (improved since it`s drier aloft) and near surface cool
air advection through morning. Putting the brakes on low cloud
development so far is the recent uptick in sea surface temperatures
with the loss of cold water upwelling due to the recent northward
moving remnant low center passing by to our west. The buoys show
sea surface temps in the upper 50s to lower 60s, about 3F to 8F
above July normals. However, northwest winds (and upwelling) will
resume in our coastal waters today and tonight.

High pressure aloft will continue to bring stable weather. Daytime
highs today will be in the 60s/70s coastside to the 70s/80 bayside
and 80s/90s inland including 90s/100 over the southern interior.
Lows in the 50s to lower 60s tonight.

&&

.LONG TERM...
Issued at 1245 AM PDT Thu Jul 23 2026
(Friday through Wednesday)

A gradual turn toward less humid conditions with a slight warming
trend inland develops through the weekend into next week. Onshore
breezes will prevail with night and morning coastal low clouds and
fog, possibly a few patches of light drizzle.

&&

.AVIATION...
(12Z TAFS)
Issued at 425 AM PDT Thu Jul 23 2026

The marine layer is 1400 feet deep, and is battling some dry air.
As such the stratus coverage is ragged and flight conditions are
likely to change for better or worse as this mixing continues
through the early morning hours. The confidence is very low with
this set of TAFs, even in the short term. The clouds will retreat
back to the coast late this morning with VFR conditions and
moderate onshore winds through the afternoon.

Vicinity of SFO...Very tricky forecast here. Boundary layer
averaged winds are from the NW, and with the compressing marine
layer the terminal is getting some IFR stratus from the west, MVFR
stratus from the east, and clear skies to the south. Since the
terminal is at the intersection, the flight condition is liable to
change quickly through the morning hours. Don`t put too much trust
in my TAF this morning. The clouds will clear in the late morning
with strong onshore winds expected from late morning through the
evening.

SFO Bridge Approach...Currently clear and very slowly filling with
IFR ceilings from the north.

Monterey Bay Terminals...MRY actually reported fog for a brief
period this morning, but that has lifted to a LIFR stratus deck.
The marine layer is very ragged across the Monterey Bay region,
but it`s unlikely that MRY or SNS clear before the late morning
hours.

&&

.MARINE...
(Today through Tuesday)
Issued at 908 AM PDT Thu Jul 23 2026

Moderate to fresh NW winds persist with embedded strong gusts,
allowing wave heights to remain moderate through the weekend. A
long period southerly swell from Hurricane Fausto also continues
to build this weekend and persists into early next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from Saturday morning through Tuesday
     afternoon for CAZ006-505-509-529-530.

PZ...Small Craft Advisory until 9 PM PDT Friday for Mry Bay.

     Small Craft Advisory from 3 PM this afternoon to 3 PM PDT
     Saturday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt
     Reyes 0-10 nm.

     Small Craft Advisory until 3 PM PDT Saturday for Pigeon Pt to Pt
     Pinos 0-10 nm.

     Small Craft Advisory until 3 PM PDT this afternoon for Pt Pinos
     to Pt Piedras Blancas 0-10 nm.

     Gale Warning from 3 PM this afternoon to 9 AM PDT Friday for Pt
     Pinos to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...Flynn
MARINE...Navarrete

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