FXUS66 KMTR 061844
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1144 AM PDT Sun Sep 6 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1143 AM PDT Sun Sep 6 2026
- Hazardous conditions at Pacific Coast beaches through Monday
- Warming and drying trend Monday through Thursday with
widespread moderate to areas of major HeatRisk
&&
.SHORT TERM...
Issued at 1143 AM PDT Sun Sep 6 2026
(This afternoon through Monday)
Hazardous conditions at Pacific Coast beaches continues to be the
weather headline through Monday. Long period southerly swell from
distant Hurricane Marie will result in an increased risk for sneaker
waves and strong rip currents with breaking waves up to 10 feet.
Stay off the beach and remain out of the water to mitigate your
risk. Minor coastal flooding will be possible during high tide this
evening for bayshore locations along the San Pablo Bay in Marin
County. Today will be the last day of well below normal temperatures
before the warming and drying trend kicks off Monday. The marine
layer continues to struggle to come back in full force with low
confidence in it doing so through Monday and even into the long term
forecast.
&&
.LONG TERM...
Issued at 1143 AM PDT Sun Sep 6 2026
(Monday night through next Saturday)
Anomalously high heights from upper-level ridging across the Desert
Southwest will nose in from the east on Tuesday, peaking Wednesday
into Thursday. The forecast has trended significantly warmer and
drier. The reason being an upper-level shortwave trough will dig
well of the West Coast and join forces with Post-Tropical Cyclone
Marie and become a cutoff low. The overall weakness of the low and
its independence from the jet stream will give the ridge precedence
over the forecast as its allowed to join forces with ridging over
the Northeastern Pacific Ocean. A weaker than normal sea breeze
circulation will mean that even the coast will be impacted due to
limited onshore flow and thus marine layer formation. There is now
widespread moderate to areas of major HeatRisk, meaning that at this
point a Heat Advisory would be needed for most of the area Wednesday
and Thursday. Temperatures will be 10 to 15 degrees above normal and
likely feel worse due to us coming off the heels of well below
normal temperatures. To put this upcoming event into context, 850 mb
temperatures and 500 mb heights will be between the 90th percentile
and record values. Needless to say, rain chances from remnant
tropical moisture have been wiped out. An approaching upper-level
trough will tamp down the ridge Friday into next weekend, cooling
temperatures to near normal and increasing onshore flow.
&&
.AVIATION...
(18Z TAFS)
Issued at 1045 AM PDT Sun Sep 6 2026
VFR as low stratus has cleared the Bay Area terminals and fog
dissipated across the North Bay. Expect west to northwesterly
winds to increase late this morning and more so by the afternoon
before easing after sunset. Low to moderate confidence of stratus
returning tonight into Monday morning. VFR conditions return by
late Monday morning once any low clouds that do develop dissipate
and give way to sunny sky conditions. Onshore winds also increase
by Monday afternoon.
Vicinity of SFO...VFR. High confidence for VFR conditions to
prevail through the evening with increasing onshore winds with
gusts up to 25 kt this afternoon. Winds ease a bit late in the
evening with the potential for MVFR CIGs to return early Monday
morning, however confidence is low to moderate (20-45% probability
based off of the NBM). Any low CIGs that do develop will
dissipate by around 16Z-17Z Monday with VFR conditions returning
and increasing onshore winds.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Onshore winds increase this
afternoon and early evening before diminishing after sunset. There
is a 20-55% probability of seeing MVFR conditions returning after
09Z Monday and 30-40% of IFR conditions between 10Z-16Z. Thus,
have introduced IFR/MVFR CIGs around 12-17Z.
&&
.MARINE...
(Today through Friday)
Issued at 1045 AM PDT Sun Sep 6 2026
Northerly winds gradually strengthen today from moderate to fresh
with strong gusts becoming more widespread. Locally stronger gusts
are expected within the Monterey Bay, coastal jet regions, and
within the Golden Gate channel. Winds diminish everywhere except
the far northern outer waters by late Monday with weaker winds to
prevail through the rest of the week. Long period southerly swell
associated with tropical activity in the Eastern Pacific will
continue to impact the coastal waters into next week.
&&
.BEACHES...
Issued at 538 PM PDT Sat Sep 5 2026
A Beach Hazards Statement is in effect through Labor Day as the
swell from tropical cyclones Marie and Karina reach the coast.
Waves from these cyclones will travel over 1,000 miles in all
directions, gradually flattening out to low amplitude, but long
period swell. These waves aren't very intimidating if you're on a
boat in the open ocean, but the long period allows them to push
much farther up the beach. Long period swell always increases the
chance for sneaker waves, but that's particularly true this
weekend since there are 2 different sets of southerly swell, and
their energy will periodically combine. In addition to sneaker
waves, expect strong rip currents and breaking waves up to 10 ft.
As this is a holiday weekend and the weather is otherwise pretty
nice, the exposure to the risk is high. Avoid the water if you're
not an expert swimmer. If caught in a rip current, swim parallel
to shore until you stop feeling the pull. Even on the beach, be
prepared for sneaker waves this weekend and never turn your back
on the ocean.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday evening for CAZ006-505-
509-529-530.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.
Small Craft Advisory until 3 AM PDT Monday for Pigeon Pt to Pt
Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Small Craft Advisory from 9 PM this evening to 9 AM PDT Monday
for Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...RGass
MARINE...RGass
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Prepared by Boulder-Creek.com Weather at: Sun Sep 6 14:30:02 PDT 2026
From the National Weather Service
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