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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS66 KMTR 200555
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1055 PM PDT Fri Apr 19 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1206 PM PDT Fri Apr 19 2024

A bit cooler across the board today with cloud cover in addition
to a deeper marine influence. Continued cloudiness to start the
weekend and a dry stretch going into next week. Potential
drizzle/light rain chances mid-to-late next week.

&&

.UPDATE...
Issued at 824 PM PDT Fri Apr 19 2024

It`s a relatively quiet evening across the area with low stratus
already onshore across portions of the North Bay and along the Big
Sur coast. Given the relatively deep/moist marine layer expect
stratus to expand to encompass much of the region late tonight
into Saturday morning before clouds retreat to the coast by
afternoon. Some orographically enhanced drizzle is possible
tonight along the coast as well. This is all represented in the
going forecast which is in good shape. Therefore no update is
needed for this evening.

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 1206 PM PDT Fri Apr 19 2024

Well defined marine layer up to about 2,000 feet remains in place
this afternoon per Fort Ord profiler. Expecting this to remain in
place through into Saturday as the responsible upper low moves
through and the onshore flow increases through tomorrow. Though
the deep marine layer remains locked in through Saturday, the
associated cloud cover will mix out during the afternoon, much
like today, and give way to a rather pleasant afternoon. Locations
right along the coast may see more persistent cloud cover lasting
later in the day, however. Otherwise, expect northwest winds to
increase Saturday afternoon, becoming breezy up to 25-35 mph along
the coast and nearby coastal hills.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 1206 PM PDT Fri Apr 19 2024

To end the weekend and start next week, ridging takes over the
pattern once again with afternoon highs increasing by a couple of
degrees for Sunday and Monday. Tuesday brings the next big change
in the weather as the well-advertised upper low moves into the
region. The most notable changes that will be noticed Tuesday are
cooler temps and increased cloud cover. Really not much change to
the forecast beyond that through the rest of the week. Certainty
regarding rainfall remains about the same with still only about
25 out of 100 members advertise anything measurable. Again, the
most likely scenario as of now will be drizzle in the hills and
coastal areas with perhaps some pockets of sprinkles here and
there.

&&

.AVIATION...
-- Changed Discussion --
(06Z TAFS)
Issued at 1055 PM PDT Fri Apr 19 2024

Current VFR conditions tonight are expected to give way to scattered
MVFR/IFR conditions. Terminals nearest to the coast are the most
favored to see conditions deteriorate to MVFR/IFR as stratus
slowly makes its way to the coast overnight. However, confidence
in CIG development is only moderate, as the 00Z KOAK sounding
indicates a decent dry layer in the mid to lower atmosphere.
Mixing of winds aloft may help to dry out the lower atmosphere as
well. Model soundings also seem to reflect this. This may inhibit
stratus development and prevent it from becoming as widespread in
coverage as in previous nights. That being said, any CIGs that do
develop tonight should be lower than those seen last night now
that the shortwave trough has exited, which would have provided
more lift. Lacking that tonight, the marine layer sits around
1300-1500` approximately. Thoughts are that terminals impacted by
stratus tonight will see CIGs in the IFR range predominantly, and
just a few on the cusp of MVFR. Clearing of stratus expected on
the earlier side in the morning of Saturday, generally around 16Z.
Into the afternoon, breezy to moderate onshore winds increase and
last through the evening, with wind shear developing in the North
Bay and select SF bay terminals.


Vicinity of SFO...Currently VFR, expected to become MVFR in the
early to mid morning of Saturday as low clouds develop. Current
satellite imagery shows stratus just beginning to push into the SF
bay. Clearing of stratus towards 16/17Z, with moderate to high
confidence. Onshore winds moderate and gusting to around 25 knots in
the afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus currently sits away from the coast,
but is expected to impact the terminals shortly, bringing IFR CIGs.
The Ft. Ord profiler shows a much more compressed marine layer
compared to last night, bringing higher confidence in the
development of IFR CIGs. Clearing is expected towards 17Z, and winds
increase into the afternoon to become onshore and breezy once more.
Stratus does not appear to make a return until after the current TAF
period.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
(Tonight through next Thursday)
Issued at 1055 PM PDT Fri Apr 19 2024

Light to moderate breezes continue through Friday night before
northwesterly winds increase to become strong and gusty Saturday
evening. Swell builds into Sunday out of the northwest as gusty
conditions continue but looks to diminish towards the middle part
of the next week. Light southerly swell continues to move through
the waters this weekend and through the next work week.
-- End Changed Discussion --

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM Saturday to 3 AM PDT Sunday for
     Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos
     10-60 NM-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 from 9 AM to 9 PM PDT Saturday for Pt Pinos
     to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...AC
MARINE...SO

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