FXUS66 KMTR 101754
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1054 AM PDT Sat Oct 10 2026
...New AVIATION, MARINE, BEACHES...
.KEY MESSAGES...
Updated at 927 PM PDT Thu Oct 8 2026
- Sharp cool-down this weekend and early next week
- Coastal flooding during high tides through mid-week
- Beach Hazards Saturday morning until Monday evening
- Light rain possible north Central Coast early next week
&&
.SHORT TERM...
Issued at 1152 PM PDT Fri Oct 9 2026
(Tonight through Sunday)
Much cooler air quickly flowed inland Friday with about equally
weighted northerly ACV-SFO and onshore SFO-SAC pressure gradients
supporting northwest winds. Current 24 hour temperature trends
remain sharply lower by up to double digits Fahrenheit across
higher elevations and inland. Surface temperatures across the
highly varied terrain in our forecast area show only a few places
left at highest elevation that are still relatively mild from the
mid 60s to lower 70s. Due to a pattern shift with upper level
troughing forecast to dominate our weather through the weekend,
the lower level temperature inversion is already steadily weakening
and lifting. The marine layer depth continues to increase, currently
between ~ 1700 and 2500 feet. Cooling applied to the marine layer
with upsloping winds will produce light patchy drizzle from San
Francisco southward to the Big Sur coastline, including the East
Bay hills tonight and Saturday morning.
Cold air advection continues through Saturday greatly weakening
the lower level temperature inversion that's capping the marine
stratus. Expect plentiful vertical mixing with drier air and
daytime surface heating to mix out the stratus by early afternoon.
Highs and lows Saturday and Sunday will be below to much below
normal for the time of year. Highs in the 60s/70s, warmest inland.
Lows in the 40s/30s, coldest far inland valleys, except near 50
along the immediate coastline and bays.
&&
.LONG TERM...
Issued at 1152 PM PDT Fri Oct 9 2026
(Sunday night through next Friday)
500 mb troughing will prevail with mainly drier air flowing
southward across our forecast area early to mid next week. There
may be a little light measurable shower activity in the southernmost
forecast area later Sunday and Monday. However, recent NBM has
trended drier to less than 0.10" liquid precipitation. 500 mb
ridging will advance eastward over our forecast area mid to late
next week, bringing a return to warmer daytime temperatures.
&&
.AVIATION...
(18Z TAFS)
Issued at 1034 AM PDT Sat Oct 10 2026
A cold front is currently sweeping through the region helping to
scour out the cloud deck across Bay Area terminals this morning.
The fropa will usher in stronger winds as well. Expect a well
mixed BL this afternoon with stronger onshore flow. For tonight,
a little bit of strato-cu may develop over the hills and Monterey
Bay region. Will keep most terminals VFR, but have MVFR CIGs for
MRY and SNS with a 40-50% conf.
Vicinity of SFO...Improving CIGs through 18Z. Gusty onshore this
afternoon with gusts 25-30 kts.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Pre-frontal stratus lingering through 19Z
then mixing out as the front moves closer and eventually through.
Post frontal clouds late tonight and early tomorrow 1500-2000
feet.
&&
.MARINE...
(Today through Thursday)
Issued at 1034 AM PDT Sat Oct 10 2026
A passing cold front will continue to produce dangerous
conditions over the coastal waters this weekend. Fresh breezes to
Gale force northwest winds will occur. Expect frequent gale force
gusts in exposed waters along with rough to very rough seas
building in response to the strong winds. On top of the hazardous
winds and rough wind waves, two sets of swell haver arrived, from
both the south and west. The significant wave height will reach 16
feet in the northern outer waters.
&&
.BEACHES...
Issued at 1055 AM PDT Sat Oct 10 2026
Heading to the beach this weekend? The sun will be out, but
beaches conditions will be less than ideal. A cold front will
bring gusty winds over the coastal waters and nearby beaches.
More importantly, the surf zone will remain very energetic. Long
period southerly swell from distant Tropical Storm Rachel will
build in height through the weekend, bringing an increased risk of
sneaker waves and strong rip currents. Long period westerly swell
from a gale force low in the Central North Pacific will arrive
Sunday, bringing breaking waves 13-16 feet. The large tidal swings
will also result in coastal erosion as water and waves are
brought farther up the beach than normal, especially during high
tide. Remain off jetties, piers, rocks, and other waterside
infrastructure as waves can sweep across the shoreline without
warning, pulling people into the sea. Remain out of the water to
avoid hazardous surf and strong rip currents and never turn your
back on the ocean!
MM
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday evening for CAZ006-505-
509-529-530.
Coastal Flood Advisory until 3 PM PDT Tuesday for CAZ006-508-529-
530.
Coastal Flood Advisory until 4 PM PDT Wednesday for CAZ506.
PZ...Small Craft Advisory until 9 PM PDT this evening for SF Bay N of
Bay Bridge.
Small Craft Advisory until 9 AM PDT Sunday for Mry Bay-Pt Reyes
to Pigeon Pt 0-10 nm.
Gale Warning until 9 PM PDT this evening for Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory until 3 PM PDT Sunday for Pigeon Pt to Pt
Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Gale Warning until 9 AM PDT Sunday for Pt Arena to Pt Reyes 10-
60 NM.
&&
$$
SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...MM
MARINE...MM
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Prepared by Boulder-Creek.com Weather at: Sat Oct 10 12:30:03 PDT 2026
From the National Weather Service
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