580
FXUS66 KMTR 180951
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
251 AM PDT Sat Oct 18 2025

...New MARINE...

.KEY MESSAGES...
Updated at 106 AM PDT Sat Oct 18 2025

 - Warming and drying trend through the weekend with light
   offshore winds in the higher elevations into early next week

 - Long period northwesterly swell will bring an increased risk of
   sneaker waves and rip currents to Pacific Coast beaches through
   the day

 - Slightly cooler conditions next week with unsettled weather
   potentially returning next Friday into the following weekend

&&

.SHORT TERM...
Issued at 106 AM PDT Sat Oct 18 2025
(Today and tonight)

Satellite imagery shows generally clear conditions across the region
with a few patches of stratus. With California under the influence
of a ridge across the western US and a cut off low off the coast of
Baja California, the marine layer remains compressed and light
offshore flow continues in the higher elevations. Thus, minimal
stratus development is expected through the night and skies remain
generally clear through the day with a light onshore breeze in the
afternoon. There is still a slight risk for fog development in the
North Bay, mainly across the Sonoma County valleys, where early
morning commuters are advised to prepare for reduced visibility and
slow down if they encounter patches of fog.

Low temperatures this morning range from the lower to middle 50s
across most of the region, with some of the higher elevations
reaching the upper 50s to the lower 60s while the far interior
Monterey and San Benito County valleys seeing lows dipping into the
middle to upper 40s. Today`s highs range from the upper 70s to the
middle 80s inland, to the middle 70s to lower 80s along the Bays,
the middle 60s to lower 70s along the Pacific coast, and the middle
to upper 60s along the ridgelines.

A Beach Hazards Statement is out through 11 PM tonight due to an
increased risk for sneaker waves and rip currents. Further
information can be found in the Beaches section below.

&&

.LONG TERM...
Issued at 106 AM PDT Sat Oct 18 2025
(Sunday through Friday)

Temperatures remain near or slightly above the seasonal average
through Tuesday with the ridge continuing across the western United
States. A slight cooling trend begins on Wednesday as the cut off
low moves into southern California, with a rebuilding marine layer
being the main impact to sensible weather. Light offshore is
possible in the interior mountains, keeping those areas drier, but
recent rainfall and high fuel moistures will alleviate the fire
weather concerns.

There has been little change in the forecast for the later part of
next week, when a deep trough forms in the Gulf of Alaska and
migrates towards the West Coast. The previous discussion still
applies: Looking farther out, the CPC is continuing to advertise a
potentially significant Atmospheric River impacting the West Coast
10/25-10/27. The major changes since the overnight update was to
expand the high risk of heavy precipitation into the North Bay and a
moderate risk of heavy precipitation into the the rest of the Bay
Area and majority of the Central Coast. The CPC is additionally
highlighting a moderate risk of high winds for the North Bay and a
slight risk of high winds for the rest of the Bay Area and Central
Coast with this system. This system is still over a week out so the
exact system of the track and QPF totals are likely to fluctuate as
we get closer. Residents should stay up to date on the forecast as
this system approaches in order to have the most accurate
information as to what weather to expect.

&&

.AVIATION...
(06Z TAFS)
Issued at 946 PM PDT Fri Oct 17 2025

VFR through the TAF Period. Expect moderate winds to turn light into
the evening and stay light through the night. LVK and SNS will see
some easterly winds into the mid morning but become light and
variable for LVK while SNS turns more northwesterly for the
afternoon. Expect mostly light to moderate winds for Saturday.

Vicinity of SFO...VFR through the TAF period. Moderate winds linger
into the late evening before becoming light and variable through the
night and much of Saturday. Expect moderate west winds to return in
the late afternoon on Saturday, but reduce into that late evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. Expect winds to
reduce through the evening becoming light and variable for the
night. Southeast winds affect SNS in the mid morning but these winds
turn northwesterly for the afternoon as MRY`s winds turn westerly.
These winds become light and variable into the night.

&&

.MARINE...
(Today through Thursday)
Issued at 250 AM PDT Sat Oct 18 2025

Fresh to strong northwest gusts will continue for the northern
outer waters into the evening. A longer period northwesterly
swell arrives this weekend 7 to 10 feet at 15 seconds. Northerly
winds should become fresh to strong late Sunday into Monday, with
near gale to gale force gusts expected for the outer waters north
of Point Pinos. Elsewhere during this time, gusts will generally
range from fresh to strong breezes. Near gale force gusts will be
possible near shore north of Point Reyes.

&&

.BEACHES...
Issued at 106 AM PDT Sat Oct 18 2025

A Beach Hazards Statement is in effect through 11 PM tonight as a
long-period swell impacts the Pacific coast. The San Francisco and
Point Arena buoys have begun reporting swell periods of 19 seconds.
The long-period swell increases the risk of sneaker waves and rip
currents across the Pacific coast, potentially catching unaware
swimmers off-guard. Never turn your back to the ocean! Swim near a
lifeguard if possible! If caught in a rip current, swim parallel to
shore until you escape its influence.

Beyond the expiration of the Beach Hazards Statement, another long
period swell arrives in the early part of next week with a Beach
Hazards Statement or a High Surf Advisory possible depending on how
the forecast evolves.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through this evening for CAZ006-505-509-
     529-530.

PZ...Small Craft Advisory until 9 PM PDT this evening for Pt Arena to
     Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Murdock
MARINE...KR

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