453
FXUS66 KMTR 100527
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
927 PM PST Sun Nov 9 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1234 PM PST Sun Nov 9 2025

 - Warming and drying trend through Monday

 - Unsettled weather pattern returns midweek and potentially lingers
   into the upcoming weekend

&&

.UPDATE...
Issued at 921 PM Sun Nov 9 2025

Satellite shows a southerly surge moving up the Monterey coastline
with a marine weather statement for fog and reduced visibility in
effect for the marine environment through tomorrow morning. Lowered
visibilities and fog are expected along the coastline overnight but
fog is not expected to make it to inland communities. The 00Z OAK
sounding shows a fairly dry environment across the interior in both
the lower and mid levels of the atmosphere with light offshore flow
continuing across the surface and higher elevation. Continuing
offshore flow will keep interior areas warmer and drier overnight,
reducing the spread of fog/stratus inland. Confidence continues
to grow in a potentially impactful atmospheric river arriving in
the Wednesday-Thursday time frame so take advantage of the nice
weather through Tuesday to complete any outdoors storm
preparations.


&&

.SHORT TERM...
Issued at 1234 PM PST Sun Nov 9 2025
(This evening through Monday)

Another warm day is in store for the region as mostly sunny skies
prevail (just a few passing high clouds). As such, temperatures are
forecast to warm into the the low-to-mid 80s across the interior
with the warmest spots across the interior Central Coast approaching
90 degrees F. Near the coast and in the coastal adjacent valleys,
expecting low 70s to low 80s. A southerly surge is moving northward
along the Big Sur coastline, yet should mostly impact locations
along the immediate coast across this region.

Tonight, expecting low clouds and/or fog near the coast as a shallow
marine layer deepens slightly to around 500 feet. However, weak
offshore winds prevail across the higher elevations will keep drier
conditions in those areas.

Monday is forecast to be our warmest day of the week (especially
inland). Any low stratus and/or fog that does develop will quickly
retreat to the coast by late morning or early afternoon. However,
onshore flow is likely to keep coastal temperatures a few degrees
lower and inland temperatures a few degrees warmer than what is
forecast for this afternoon.

&&

.LONG TERM...
Issued at 1234 PM PST Sun Nov 9 2025
(Monday night through next Saturday)

On Tuesday, the ridge begins to shift eastward which will start a
cooling trend as onshore winds become more widespread (even in the
higher elevations). However, afternoon temperatures will remain 5-15
degrees above seasonal averages.

By Wednesday, high level clouds will increase across the region
ahead of an approaching weather system bringing temperatures closer
to seasonal averages. Rain looks to be greatest from Wednesday night
through early Thursday morning as an atmospheric river takes aim on
the Bay Area and Central Coast. The coastal ranges and inland
hills/mountains in the Bay Area and North Bay have the greatest
potential (60%+) of seeing greater than 2.00" from 4 AM Wednesday
through 4 AM Friday. The North Bay Valleys and San Francisco could
see up to 1.50" with generally less than or around 1.00" for the the
remainder of the region. Given this is an atmospheric river, the
rain shadowed valleys may receive much less with respect to
rainfall. Southerly winds will increase ahead of the cold front, but
exact strength of these winds still remain in question. However,
expect the strongest winds to be along the coastline and in the
higher elevations across the region. There is also a less than 15%
probability of thunderstorms Wednesday night and into Thursday as
the main band of convection moves across the region. Once we get in
the range of the higher resolution forecast models, we will be able
to nail down the details (wind, rainfall amounts, thunderstorm
potential, etc).

From the previous forecaster: "After the main rain band moves out
late Thursday, an extended period of lighter rain, possibly showery
in nature, lingers Friday into the upcoming weekend. The axis of the
upper level trough crosses into the state early on Friday, promoting
unstable conditions resulting in the possible development of
convectively driven showers. There is also a chance that a cut-off
low could develop off the coast of southern California, which could
enhance the rain potential across the Central Coast. That said, with
the moisture tap moving to the south and into southern California
and Baja California, there will be less moisture for the showers to
tap into, and the rain totals for this part of the system trend
lower than those on Wednesday and Thursday. The precipitation
chances start out around 40-60% on Friday morning and steadily
decrease into Saturday.

Beyond the 7 day outlook, ensemble model means are suggesting
another trough may develop somewhere around the Day 8-9 (the 16th
and 17th) timeframe, bringing another chance of rain to the region.
This far out, attempting to tease out any further details is a
fool`s errand."

&&

.AVIATION...
(06Z TAFS)
Issued at 919 PM PST Sun Nov 9 2025

Ample high clouds streaming overhead making it hard to track the
progress of the southerly surge. Have delayed CIGS for KHAF and
KSNS as they have not materialized yet. Elsewhere, VFR with
diurnal winds developing and drier offshore flow. KMRY,KSNS,KHAF
have the best chance for cigs tonight and early Monday. Nailing
down wind direction is lower confidence given the lack of
stronger synoptic forcing.

Vicinity of SFO...Light winds with high clouds. Stronger onshore
push Monday afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Lower cigs have entered MRY Bay, but not
making it inland just yet. High clouds may be limited cool and
inland intrusion of clouds. When clouds do move inland they`ll be
shallow with low cigs likely under 1k feet.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 919 PM PST Sun Nov 9 2025

Southerly flow continues to surge north along the Central coast
bringing low clouds and locally dense fog with shifting  winds.
Areas of north of the Golden Gate will remain light to  moderate
winds and out of the north. Southerly surge ends Monday  with
northerly flow all waters. Unsettled weather returns midweek  with
increasing southerly winds. These winds, combined with a  building
NW swell, will generate rough seas across the waters.  Winds are
expected to decrease Friday, but the larger swell  continues to
build with seas up to 15 feet before diminishing  through the
weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...MM
MARINE...MM

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