211
FXUS66 KMTR 132331
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
331 PM PST Mon Jan 13 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 128 PM PST Mon Jan 13 2025

Winds ramping down this afternoon, giving way to a quiet pattern
with dry conditions expected through the long term forecast.

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 128 PM PST Mon Jan 13 2025

Clear skies and cool temps abound under a dry airmass and weak
offshore flow. A weak closed upper low off the coast of SoCal moved
through this morning, leading to a brief period of gusty winds that
are still lingering in some areas, but are easing through midday. As
such, the Wind Advisory has been cancelled, and is no longer in
effect. Not really much else to talk about for the daytime today.
Chilly overnight temperatures will be the story again tonight with
temps in the mid-to-upper 30s across most interior areas, and even
some coastal areas such as Santa Cruz and the Monterey Bay area. A
Frost Advisory has been issued for all of the interior North Bay,
Bay Area, and Central Coast, as well as the Monterey Bay coastal
areas for tonight until 9 AM Tuesday morning.

Regarding smoke in the sky; you may notice a slightly more reddish
hue to the sunset this evening thanks to some very light smoke
concentration from some burning up in Canada, as well as the SoCal
fires. This smoke is not expected to cause any issues since it
will mostly be aloft and will be drifting out over the waters.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 128 PM PST Mon Jan 13 2025

Quite a quiet pattern with quite the signal for no rain in quite a
while. Make sense? Good. (coffee-fueled meteorologist brain fog
enters the chat)

Longwave ridging over the northeast Pacific and Gulf of Alaska with
a few embedded shortwaves dominates the West Coast pattern through
the next seven days. However, none of these cold-core shortwave
troughs will be deep enough to overcome the broad ridge pattern that
will eventually envelope the West Coast by mid-to-late this week.
These shortwaves feed into a deeper upper low out of the Hudson Bay,
promoting a very cold setup much of the rest of the US. However,
this also promotes a highly amplified ridge over the West Coast
which appears to remain stagnant through much of the last half of
the month as the Hudson Bay low persists. Unfortunately for us, this
means there is very little to no chance of rain for the second half
of January. The good news is that most of the Bay Area, and the
North Bay especially, have seen decent rain so far this year, so
fuel indices in regard to fire weather will take some time to
respond. Central Coast fuels are more on the drier side and will
dry out more quickly though. Will certainly be something to keep
an eye on through these next couple of weeks.

&&

.AVIATION...
(00Z TAFS)
Issued at 331 PM PST Mon Jan 13 2025

High confidence of VFR through the TAF period. Gusty offshore winds
are diminishing into the evening, and remain light and variable
overnight. On Tuesday some light onshore flow is possible at the
immediate coast, with offshore flow continuing in the interior.

Vicinity of SFO... VFR through the TAF period. Offshore flow
continues through the evening with light and variable winds through
Tuesday morning. A shift to light onshore flow is possible on
Tuesday afternoon.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR with offshore winds through the
evening, possible valley drainage winds overnight. Winds shift
onshore late Tuesday afternoon.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 331 PM PST Mon Jan 13 2025

Generally weak winds will persist through much of the week as high
pressure remains over the region. Wave heights will also remain
relatively low, generally between 4 and 7 feet. Northwest winds
will increase as well as wave heights late in the week and into
the upcoming weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory from 1 AM to 9 AM PST Tuesday for CAZ504-506-510-
     512>518-528>530.

PZ...None.
&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...DialH
MARINE...RGass

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