Stinson Beach, California Weather Forecast Discussion

542
FXUS66 KMTR 020801
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
Issued by National Weather Service Eureka CA
101 AM PDT Thu Oct 2 2025
...New SHORT TERM, LONG TERM, MARINE...
.KEY MESSAGES...
Updated at 115 PM PDT Wed Oct 1 2025
- Showers moving south through the day with slight chance for
   thunderstorms in the interior Central Coast.
- Gusty winds developing on Friday
- Gradual warming trend begins this weekend with moderate
   offshore winds
&&
.SHORT TERM...
Issued at 1254 AM PDT Thu Oct 2 2025
(Today and tonight)
The 6Z WPC surface analysis depicts a stationary front parked
just off the coast of the Bay Area with a weak low pressure center
off of Monterey Bay. The offshore low pressure center has been
relatively still since it formed off the coast of Mendocino County
yesterday morning, but it will wade its way through the state
today, dragging the front with it. Thus, the band of scattered
showers that remains over the Bay Area should start to move
southward, leaving the Bay Area behind by the afternoon hours and
clearing the Central Coast through the late evening. Rainfall
totals are expected to be light, at most around a quarter of an
inch in the favored upslope regions of the Santa Cruz and eastern
Santa Clara Mountains.
A complicating factor will be the chance for thunderstorms in the
interior Central Coast as the front moves through this afternoon
and early evening. Thinking back to the three ingredients for
convection: moisture will come from a trailing system whose
moisture is being dragged into the state. Instability will come
from a developing upper level low moving into the state, with K
Index values of 30-35 degrees C suggesting the possibility for
scattered thunderstorms. Lift could come from the local topography
as is quite common in the area, but the cold front itself will
provide another source of lift, extending the thunderstorm risk
into areas of the Central Valley. The latest forecast update shows
the probability of thunder rising to around 15-20% across most of
San Benito County, with chances for thunderstorms around 10-15%
across Monterey County and the southern and eastern sections of
Santa Clara County.
Behind the front, expect a rather chilly day with high
temperatures ranging from the lower to middle 70s in the inland
valleys, and the upper 70s to lower 80s in southern Monterey
County, to the upper 60s to lower 70s along the bays, and the
lower to middle 60s near the Pacific coast. For context, these are
around 5 to 10 degrees below seasonal averages. Lingering showers
are possible through the night, especially in the interior
portions of the forecast area.
&&
.LONG TERM...
Issued at 1254 AM PDT Thu Oct 2 2025
(Friday through Wednesday)
The strong upper level low will move through the state through
Friday, with drier conditions across the region with the moisture
having moved off to our south. A strong pressure gradient over the
Bay Area and Central Coast will enhance northwesterly winds
across the region, with wind gusts reaching 25 to 35 mph at the
immediate coast, within the Salinas Valley, and through favored
gaps and passes across the region. Wind Advisories may prove
necessary if confidence in more widespread gusty winds increases.
Temperatures will be around the same as today for the Bay Area
with a drop expected in the Central Coast, with the southern
Monterey Bay region and northern Salinas Valley seeing highs in
the lower to middle 60s, while the warmest locations in southern
Monterey County reach highs in the lower to middle 70s.
The weekend features a warmup as the upper level low moves off
into the Great Basin. High temperatures range from the middle 70s
to the lower 80s in the inland valleys, the lower to middle 70s
close to the Bays, and the middle to upper 60s along the Pacific
coast. A surface high will develop in the northern Rockies,
setting up the possibility for moderate offshore flow Saturday
through Monday. These would usually raise fire weather concerns,
but the antecedent rainfall and the limited strength of the
offshore flow will mitigate the risk. The latest update of the
PGE-WRF model shows the SFO-WMC gradient reaching -2 to -6 mb,
which will cause some offshore flow, but keep it from being strong
enough to warrant any critical fire weather threats.
Beyond Monday, upper level troughing is expected to persist over
the western United States, at least through the middle part of
next week. CPC outlooks lean towards temperatures and
precipitation totals near the seasonal average into the middle
part of October.
&&
.AVIATION...
(06Z TAFS)
Issued at 1037 PM PDT Wed Oct 1 2025
VFR-MVFR ceilings and visibilities will lower to MVFR-IFR tonight
and Thursday morning. Scattered showers continue across the
forecast area with a slow moving frontal boundary. Conditions
gradually improving to VFR by late Thursday morning and afternoon.
Low clouds redeveloping Thursday night.
Vicinity of SFO...VFR-MVFR with west to northwest wind 5 to 10
knots.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR-MVFR lowering to IFR conditions
tonight and Thursday morning. A few showers are expected through
the period. Conditions improving to MVFR-VFR by late Thursday
morning and afternoon. Low clouds /MVFR/ redeveloping Thursday
night.
&&
.MARINE...
(Today through Tuesday)
Issued at 1254 AM PDT Thu Oct 2 2025
Buoys are reporting a gentle to moderate southerly breeze with a
moderate period NW swell up to 12 feet. A weak cold front will
continue to push through the coastal waters today. After the front
passes, hazardous small craft conditions will persist as the swell
subsides, but winds increase. Building high pressure across the
Eastern Pacific will increase winds to a strong NW breeze with
near gale force gusts from Friday afternoon through early Sunday.
These winds will support rough wind waves up to 10 feet through
the weekend.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Friday
     for Mry Bay.
Small Craft Advisory from 9 PM this evening to 9 AM PDT Friday
     for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60
     NM.
Small Craft Advisory from 3 PM this afternoon to 9 AM PDT Friday
     for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm.
Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena
     to Pt Reyes 10-60 NM.
Small Craft Advisory until 9 AM PDT this morning for Pigeon Pt
     to Pt Pinos 10-60 NM.
Small Craft Advisory from 3 AM to 9 AM PDT Friday for Pigeon Pt
     to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...RK
LONG TERM....RK
AVIATION...RC
MARINE...RK
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NWS MTR Office Area Forecast Discussion