FXUS66 KMTR 091134
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
334 AM PST Mon Nov 9 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1230 PM PST Sun Nov 8 2026
- Slightly warmer and dry weather through the midweek
- Coastal flooding due to high tides through Friday
- Hazardous beach conditions through Monday
- Unsettled weather returns by late week and into the upcoming
weekend
&&
.SHORT TERM...
Issued at 1145 PM PST Sun Nov 8 2026
(Tonight through Tuesday)
Dry weather continues over our forecast area due to a nearly
stationary long wave ridge centered over the southwestern states.
Cirrus clouds with the southern extent of the polar jet stream are
moving over the North Bay while to the south it is clear. Nocturnal
radiative cooling, most pronounced south of the cirrus clouds, is
allowing continental air to cool (higher pressure), setting up a
light land breeze in contrast to the much of above Nov normal sea
surface temps in the 60s as much as +10F to +11F above Nov normal
(air in contact with the warmer sea surface temps equals lower
pressure). Surface winds flow from high pressure to low pressure,
which is keeping the warm maritime influence held to the coastline
or even nudged slightly offshore. Sea surface temps as warm as
they are could easily keep coastal night-time/morning minimum
temperature much warmer (e.g. San Francisco Aug 2015 set about a
1/2 month of record high min temps, recall El Nino of 2015-2016),
but remarkably at this time so far this has not been the case
because of continental influence. November (vs August) brings
occasional mid-latitude weather influences, much lower sun angle,
longer night time cooling hours.
Cooling tonight through daybreak Monday will produce additional
low clouds and patches of fog. Because of the much above normal
sea surface temperatures, water vapor availability is much more
robust. Daytime sea breezes temporarily usher higher water vapor
and hazy conditions inland, then when the winds turn neutral to a
light land breeze, cooling is introduced (cooling described above)
and it is easy to reach saturation. Patchy dense fog may redevelop
tonight and Monday morning. Will monitor satellite and observations
and issue a dense fog advisory if needed.
Daytime highs Monday and Tuesday will continue slightly above
normal with highs in the upper 60s at the coastline to the 70s and
lower 80s inland. Night-time lows will be in the 40s and 50s. A
very weak 500 mb trough in the flow will pass by this time
tomorrow night otherwise high pressure will prevail through early
week.
&&
.LONG TERM...
Issued at 1145 PM PST Sun Nov 8 2026
(Tuesday night through next Sunday)
An increase in northern hemispheric long wave troughs is occurring
and will continue to hold during this time-frame. One long wave
trough will strengthen over the northeastern Pacific and another
long wave trough will strengthen downstream over the eastern
states. In the 120 hour time-frame, out to Friday, the leading
edge of strong polar jet stream winds will dig southward forming a
closed 500 mb low ~ 300-400 miles to our west-southwest Thursday.
Steering winds will continue to drive the newly formed closed 500
mb low toward southern California. This may leave a cold frontal
passage with a chance of rain for our forecast area on Friday,
though this is a low confidence forecast since model output is
varying on rain amounts. Friday is five days out which is about
the max we can rely on for global model output in the complex
seasonal transition period of fall-winter. Dynamic strengthening
is forecast upstream and downstream, both within the long wave
trough over the east and to our west, but also with the ridge in
between, nudged slightly forward during this time. If the upstream
long wave trough is able to slowly advance eastward, this should
increase the chance of rain here, possibly to a greater chance
Sunday.
&&
.AVIATION...
(12Z TAFS)
Issued at 326 AM PST Mon Nov 9 2026
Another lower confidence morning due to mixed CAT from LIFR at
STS,APC,OAK to VFR other locations. High clouds streaming over the
N Bay are making it hard to track dense fog. Recent trends in SF
Bay do show shallow stratus is developing and spread across the
Bay. Expect some impacts inside the Bay during the AM rush with
dense fog at OAK. Fog at OAK may drift N and be replaced by CIGs
near sunrise.
Vicinity of SFO...VFR currently but nearby CIGs are filling in and
decided to keep the tempo of CIGs. VFR this afternoon with onshore
flow. Lower chc of CIGs returning late tonight.
SFO Bridge Approach...Stratus CIGs filling in over the S end of
the approach. CIGs linger 17zish
Monterey Bay Terminals...VFR with drainage flow to the Bay.
&&
.MARINE...
(Today through Saturday)
Issued at 326 AM PST Mon Nov 9 2026
Moderate period with longer periods will continue to produce rough
to very rough seas. Moderate to fresh northerly breezes will
prevail through Tuesday, with bays remaining more sheltered. Seas
begin to subside Tuesday and winds will back through the day
Wednesday to become southerly. A much large swell is forecast to
arrive next weekend.
&&
.BEACHES...
Issued at 330 AM PST Mon Nov 9 2026
Beach Hazards Statement:
Beach Hazard Statement remains in effect. Latest buoy obs show
the moderate swell and moderate period continue to produce an
energetic surf zone. As such, large shore break, sneaker waves,
and stronger rip currents will be possible. Breaking waves of 12
to 16 feet are expected at exposed beaches and up to 18 ft at
favored break point. Spring tides will also increase the currents
and bring higher tides than normal. Waves can sweep across the
shoreline without warning, pulling people into the sea from
beaches, jetties, and rocks. Stay off of jetties, piers, rocks,
and other waterside infrastructure. Remain out of the water if
you're not an experienced swimmer to avoid hazardous surf and
never turn your back on the ocean! There may be a lull in wave
activity midweek, but longer range forecasts show additional
swells impacting the coast next weekend.
Coastal Flood Advisory:
A combination of high astronomical tides and thermal expansion from
warmer than normal water will result in tidal flooding concerns
across Bayshore locations in the San Francisco, San Pablo, and
Monterey Bays. At the San Francisco tide gauge, high tide is
expected to be 1.6 ft above normal (7.4 ft MLLW) at 10:35 AM Monday
11/9, 1.5 ft above normal (7.3 ft MLLW) at 11:04 AM Tuesday 11/10,
1.4 ft above normal (7.2 ft MLLW) at 11:35 AM Wednesday 11/11, 1.4
ft above normal (7.2 ft MLLW) at 12:10 PM Thursday 11/12, 1.2 ft
above normal (7.0 ft MLLW) at 12:49 PM Friday 11/13. These
predictions include up to 1.5 ft of surge that will enhance the
astronomical tide and flooding threat. High tide varies up to 90
minutes earlier or later along the Pacific Coast and through the San
Francisco Bay, respectively. In addition, long-period swell will
create hazardous conditions along the Pacific coast beaches with an
increased risk of sneaker waves and rip currents.
These Spring Tides are due to a new moon on Monday, which is much
lower in the sky this time of year compared to a full moon. In 2
weeks, the astronomical tides will be about 0.8' higher than this
round, and the total water level could be more than a foot higher if
we get SW winds and/or lower pressure. This combination would bring
the total water level near the 1% annual exceedance probability
(2.85' above normal), or a 1 in 100 year event. Something to keep an
eye on for the week of Thanksgiving.
Sarment/Flynn/MM
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from 3 PM PST this afternoon through
this evening for CAZ006-505-509-529-530.
Coastal Flood Advisory from 3 PM this afternoon to 4 PM PST
Friday for CAZ006-506-508-530.
Coastal Flood Advisory from 3 PM this afternoon to noon PST
Tuesday for CAZ505-509-529.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PST this
evening for Mry Bay-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.
&&
$$
SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...MM
MARINE...MM
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Prepared by Boulder-Creek.com Weather at: Mon Nov 9 08:30:03 PST 2026
From the National Weather Service
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