246
FXUS66 KMTR 300034
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
534 PM PDT Fri Aug 29 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1256 PM PDT Fri Aug 29 2025

 - Temperatures near seasonal averages today, warming for the
   weekend through the middle of next week

 - Elevated fire weather concerns across the interior mountains
   this weekend with low RH and moderate onshore winds in the
   afternoons

 - Hazardous coastal conditions Saturday through Monday night due
   to long period southerly swell

&&

.SHORT TERM...
Issued at 1256 PM PDT Fri Aug 29 2025
(This evening through Saturday)

Stratus has cleared inland with temperatures this afternoon forecast
to warm into the upper 80s to lower 90s across the interior and in
the higher elevations, upper 60s to lower 80s just inland away from
the coast, and 60s to lower 70s near the coast/bays. Breezy onshore
winds are forecast to develop this afternoon and continue into the
evening with gusts of 25 to 35 mph in the favored gaps and passes,
Salinas Valley, and along the coast and in higher elevations.

Tonight, temperatures will cool into the 50s for most urban areas,
lower 60s across the interior valleys, and the 70s to lower 80s in
the higher terrain. Low clouds are also forecast to return inland
early Saturday morning and will dissipate by late morning. This will
bring increased humidity to lower elevations overnight, yet dry
conditions prevail in the higher elevations.

For Saturday, temperatures will warm by a few degrees with
temperatures forecast to be in the low 90s to near 100 degrees F
across the interior and in the higher elevations, low 70s to mid 80s
just inland away from the coast, and upper 60s to mid 80s near the
coast/bays. These temperatures will be 5-15 degrees F above average
for this time of year. This will result in isolated to scattered
Moderate HeatRisk across interior areas.

&&

.LONG TERM...
Issued at 1256 PM PDT Fri Aug 29 2025
(Saturday night through next Thursday)

Temperatures will hold steady as far as maximum/minimum temperatures
go through the remainder of the weekend and into early next week. As
such, Moderate HeatRisk will persist through at least through mid-
week of the upcoming week. We will need to keep an eye on the need
for any Heat products as we move into the upcoming week.

From previous forecaster: "This level of heat will bring a risk of
heat-related illnesses to vulnerable populations, including
children, the elderly, pregnant women, and people who are working or
living outdoors without adequate shelter or hydration. Near the
coasts, a compressed marine layer should retain the ability to keep
temperatures from rising dramatically, but areas that will lose the
marine layer influence, including much of the Bay Area, could see
temperatures jump 5 to 10 degrees. The heat will also contribute to
some elevated fire weather conditions across the interior mountains.
More information is available in the FIRE WEATHER section."

&&

.AVIATION...
(00Z TAFS)
Issued at 534 PM PDT Fri Aug 29 2025

It`s VFR, however coastal stratus and fog /MVFR-IFR-LIFR/ will
redevelop tonight and Saturday morning. Slightly warmer lower
level temperatures in the marine layer temperature inversion is
forecast tonight and Saturday. Stratus and fog will mix out by
late Saturday morning. Onshore winds will prevail locally gusty
during the afternoon and evening.

Vicinity of SFO...VFR except tempo stratus MVFR 12z-16z Saturday.
West wind gusts near 30 knots until 04z this evening, otherwise
west wind easing overnight to 10 knots then increasing to near 30
knots Saturday afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR continuing into the evening, stratus
and fog /IFR/ then developing tonight and Saturday morning. Stratus
and fog mixing out by late Saturday morning otherwise VFR. Winds
mainly onshore 5 to 15 knots.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 516 PM PDT Fri Aug 29 2025

Fresh to strong wind gusts are developing afternoon and look to
last through the holiday weekend along with increasing wave
heights. The gusty winds and choppy seas will create hazardous
conditions across our coastal waters through the weekend into the
beginning of the next work week.

&&

.FIRE WEATHER...
Issued at 312 PM PDT Fri Aug 29 2025

Warming and drying trend under way into this weekend as high
pressure builds aloft. Marine layer compression has begun this
afternoon with some areas showing as low 800-900 feet. Daytime
humidities will still be moderate-to-high below this elevation.
However, elevations above about 1,000 feet will see RH in the
teens during the afternoons through the weekend and into next
week. While we aren`t anticipated any long-duration wind events,
we do expect breezy NW winds to develop each afternoon during
peak heating, especially favoring gaps and passes in the East Bay
interior mountains. The energy release component (ERC) of
available fuels is showing slightly above average (higher burn
potential) for most locations across the region, with the most
notable being the North Bay zones which are forecasted to be well
above average for this time of year. Also, a fun tidbit worth
noting; we are right around our climatological peak for fuel
energy release component. Learn more about ERCs at
https://gacc.nifc.gov/oscc/fuelsFireDanger.php

Behringer

&&

.BEACHES...
Issued at 125 PM PDT Fri Aug 29 2025

Long-period (15-18 seconds) south-southwest swell originating from
previous Tropical Storm Juliette will impact the coast Saturday
through Monday night, creating an elevated risk for sneaker waves,
rip currents, and rough surf. This will be especially so at
southwest facing beaches including but not limited to Stinson
Beach, Santa Cruz Boardwalk Beach and Twin Lakes Beach. The
potential exposure to the dangers will be enhanced by the Labor Day
holiday weekend as folks flock to the coast to escape the hot inland
temperatures across the interior.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from 5 AM PDT Saturday through Monday
     evening for CAZ505-509-529.

PZ...Small Craft Advisory from 9 AM Saturday to 3 AM PDT Sunday for
     Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
     to Pt Pinos 0-10 nm.

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

     Small Craft Advisory until 3 AM PDT Sunday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Canepa
MARINE...Murdock

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