697
FXUS66 KMTR 132331
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
331 PM PST Thu Nov 13 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 131 PM PST Thu Nov 13 2025

-Impactful storm system to continue through tonight

-Active weather pattern continues through next week

-Hazardous beach conditions persist

&&

.SHORT TERM...
Issued at 131 PM PST Thu Nov 13 2025
(This evening through Friday Night)

Widespread rain showers continue to stream in ahead of a potent
upper low this afternoon. As far as wind headlines, we`ll maintain a
Wind Advisory for gusts near/above 45 mph across the Central
Coast. The Point Sur VWP continues to sample 0-1 km flow of at or
above 50 knots and this is generally in line with short-term
model guidance that advertises around 45-50 knots around 925mb.
Surface observations across this region also still indicate gusts
of 45 mph across interior San Benito, with gusts near or just
under 60 mph in a few spots along the Big Sur Coastline.

We`ll continue to see our band of showers persist through the
afternoon and into the early evening hours as forcing for ascent
continues across our area. Taking a look at some of the SPC MesoA
products, there still remains a small sliver of instability
across the extreme eastern portions of the Santa Clara Hills and
San Benito County, as well as far southern portions of Monterey
County. The overall trend, however, is diminishing, likely due to
the widespread rainfall that is flattening out mid/upper level
lapse rates. With 40 to 50 meter height falls and mid-level CAA,
there still seems to be a reasonable chance for thunder, at least
across the aforementioned geographic regions, but even this
potential is dwindling. Deep layer shear does remain plentiful,
but with the instability waning, the likelihood of organized
convective modes is on the decline. Still, we`ll monitor for any
transient low-topped organized convective modes.

For the rest of this afternoon and into the evening, our best
rain chances (and thus flood risk) will shift southward. The time-
lagged HRRR ensemble seems to align well with radar/satellite
presentations and in fact some of the precip-object tracking
items indicate that over the next 2-4 hours, the corridor of
heaviest rainfall will shift to the southern Big Sur Coastline.
This aligns well with short term NWP as the nose of the strongest
flow at 925mb will be focused here.

Upper troughing remains in place through the day on Friday. With no
real moisture being scoured out, we`ll maintain opportunities for
rainshowers. Not too atypical of these broadly forced scenarios,
there are a variety of solutions, all which have reasonable
outcomes (boom or bust). This results in a lower-confidence PoP
forecast. What I can say with confidence is that many if not most
areas will continue to have at least a 50 to 60 percent chance for
measurable rainfall given that we`ll still have broad ascent with
a moist regime (though PWATs will decrease). While it won`t
necessarily rain continuously through the day at all locales,
intermittent isolated to scattered precipitation will continue and
this is supported by hi-resolution model guidance.

Rain amounts this afternoon and into Friday night are anticipated
to average around 0.20-0.75" across the Bay Area to around 1"
across the Central Coast. Higher terrain such as the Santa Cruz
Mountains, the Diablo, Santa Lucia, and Gabilan Ranges could
average between 1-2" with isolated +3.5" (Santa Lucia) amounts.
This may support largely nuisance flooding across these areas.

&&

.LONG TERM...
Issued at 131 PM PST Thu Nov 13 2025
(Saturday through next Wednesday)

Confidence in a quasi-active weather pattern remains low to
moderate as the current upper trough is expected to detach from
the main flow and become a meandering upper low across the region.
As the parent low jogs eastward through the Central Valley, low
level 850-925mb theta-e advection will support ascent atop a
cool/moist airmass. Blended guidance seems very reasonable a PoP
gradient from near 10% or less across the North Bay to near 80%
across far southern Monterey and San Benito County.

By the end of the weekend into early next week, a broad upper
trough should kick our current low to the east. This next trough
is highly amplified and with the mid/upper level speed maxima
upstream of the main trough axis, there`s a chance that timing
could change. Cluster analysis indicates a wide array of
solutions with some scenarios advertising a swifter movement of
this feature to the east, while others delay the movement of the
trough. At any rate, large scale ascent support PoPs through just
about the entire outlook period. At this time rainfall amounts
Sunday afternoon and into Tuesday appear to be largely under 1.5",
however, we`ll fine-tune this forecast as we venture through the
weekend.

&&

.AVIATION...
(00Z TAFS)
Issued at 331 PM PST Thu Nov 13 2025

The main frontal rain band is moving to the south and east of the
main terminals, with MVFR-IFR conditions expected for those
traversing the band through the rest of the day. Behind the band,
scattered showers persist, diminishing in intensity and coverage
farther away from the band, and generally VFR with mid-level cloud
cover and MVFR conditions prevail. High-resolution models are not
picking up on the stratus potential overnight, but given the recent
rainfall and potential radiational cooling where breaks in mid- to
high-level clouds set up, have elected to keep the previous forecast
of MVFR-IFR stratus development overnight. Going for a more
pessimistic 20-21Z clearing time for most terminals on Friday,
although this is a lower confidence forecast.

Vicinity of SFO... VFR with mid-level clouds to high-end MVFR and
isolated showers persist through the evening. Light to gentle south
breezes prevail through the TAF period. Low to moderate confidence
of stratus development overnight, a slightly higher confidence at
OAK. If stratus does form overnight, expect MVFR conditions and a
late clearing time on Friday.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR conditions with mid-level clouds mixed
with MVFR conditions continue into the evening hours, with MVFR
stratus developing overnight. A gentle southeast to south breeze
will continue through the overnight hours, with light drainage flow
overnight before onshore winds resume Friday afternoon.

&&

.MARINE...
(Tonight through next Tuesday)
Issued at 331 PM PST Thu Nov 13 2025

Hazardous marine conditions are gradually diminishing from north
to south through the afternoon and evening hours. Winds will
continue to steadily decrease through the evening and overnight
hours, but remain hazardous for small craft into Friday morning.
Rough seas for the inner waters and very rough seas for the outer
waters continue through Friday. Seas abate to become moderate by
Saturday through the weekend.

&&

.BEACHES...
Issued at 124 AM PST Thu Nov 13 2025

A Beach Hazards Statement is in effect from this afternoon through
Friday evening. Long period westerly swell will result in an increased
risk for sneaker waves and rip currents. Breaking waves of 13 to 18
feet with the highest waves up to 23 feet in favored locations are
expected. Sneaker waves can unexpectedly run significantly farther
up the beach than normal, including over rocks and jetties. Rip
currents are typically more frequent and stronger in the vicinity
of jetties, inlets, and piers.

&&

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

     Wind Advisory until 4 PM PST this afternoon for CAZ516>518-528-
     530.

PZ...Small Craft Advisory until 9 PM PST this evening for Mry Bay.

     Small Craft Advisory until 1 AM PST Friday for Pt Arena to Pt
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to
     Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 AM PST Friday for 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...Bain
LONG TERM....Bain
AVIATION...DialH
MARINE...DialH

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