303
FXUS66 KMTR 150538
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
938 PM PST Tue Jan 14 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 110 PM PST Tue Jan 14 2025

Dry weather with mostly sunny skies and light winds will persist
through the week. Expect daytime highs to be around or slightly
above normal with seasonably cold morning lows.

&&

.UPDATE...
Issued at 908 PM PST Tue Jan 14 2025

Dry weather and offshore wind continues, the WMC-SFO pressure
gradient is 10.6 mb, SAC-SFO 0.4 mb and ACV-SFO is 0.8 mb. A
clear to mainly clear sky will allow radiational cooling again
tonight to daybreak Wednesday, a frost advisory was issued for 1
am to 9 am Wednesday for the southern interior zones. Surface
dewpoint temperatures (water vapor) have also increased a little
over the forecast area, there may be a few patches of valley fog
developing overnight and Wednesday morning. Please be cautious of
potential visibility reductions in patches of fog overnight and
tomorrow morning if planning to travel. Morning fog will mix out
by late morning, with a sunny to mainly sunny sky Wednesday.

&&

.SHORT TERM...
(This evening through Wednesday)
Issued at 110 PM PST Tue Jan 14 2025

Clear skies for all once again today as weak offshore flow
continues. Tonight and tomorrow will be much of the same story as
today with chilly overnight temps and a mild, cloudless afternoon.
Temperatures this morning verified the Frost Advisory in all areas
where it was issued (just based on the ambient temperature), but
conditions are too dry to actually have frost formation in many
areas. However, we continue to issue advisories based on the
ambient temperature for societal impacts.

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 110 PM PST Tue Jan 14 2025

The upper low that resulted in breezy winds yesterday morning has
closed off and is now lingering over the waters off the coast of
SoCal away from much of its initial jet influence. Therefore, it
is expected to eventually fill in and move inland by late this
week. This will promote some breezy winds Friday and Saturday
afternoons, but not expecting anything impactful at the moment.
The main point of interest this weekend will be the overnight
temperatures once again, with morning lows in the 30s for most of
the region outside of the immediate SF Peninsula and Sonoma
coastlines. Otherwise, there is high confidence that a blocking
ridge pattern will setup and persist well through the extended
forecast period with no rain in sight. We are particularly worried
yet since the energy release component of some larger fuels is
still below critical. However, drying out beyond critical can
occur very quickly over the next two weeks, especially if we make
it into the first half of February without any rainfall. In
comparison to last year and to serve as a reminder that these
mid-season dry spells are not entirely uncommon, areas south of
the Bay Area that are significantly drier than the North Bay have
actually seen more rainfall up to this point in the water year
compared to last year. The caveat to that is that we had a few
prolific rainmakers to kick off February 2024 and bring us back
to normal. It may be alarming how dry we are right now, but we
still have time to potentially turn it around.

&&

.AVIATION...
(06Z TAFS)
Issued at 938 PM PST Tue Jan 14 2025

VFR through the TAF period for all but the North Bay which will see
some pockets of fog overnight. Winds mostly stay light to moderate
with local effects driving most of the wind directions though the
TAF period. Winds around the Monterey Bay will be slightly more
unified as overnight southeast drainage winds affect the area.


Vicinity of SFO...VFR through the TAF period. Moderate northwest
winds last into the late night before becoming light and variable
for Wednesday morning and through that afternoon. Additional moderate
northwest winds arrive Wednesday evening.


SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. Moderate
northwest winds weaken into the night and turn into southeast
drainage winds overnight. These winds will arrive later into the
night for SNS, but will be more moderate compared to the lighter
winds at MRY. Expect moderate northwest winds to return mid
Wednesday afternoon.



&&

.MARINE...
(Tonight through next Monday)
Issued at 938 PM PST Tue Jan 14 2025

Expect light northerly winds continue through the end of the week
with abating seas. The Sea state will be low with moderate period
into the weekend, but look to build over the weekend as breezier
winds return.

&&

.BEACHES...
Issued at 800 PM PST Tue Jan 14 2025

Moderate period northwest swell will gradually subside late tonight
through Wednesday. There is a slight risk of sneaker waves. Remember
to never turn your back on the ocean.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory from 1 AM to 9 AM PST Wednesday for CAZ516>518.

PZ...None.
&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Murdock
MARINE...Murdock

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