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000
FXUS66 KMTR 200948
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
248 AM PDT Sat Apr 20 2024

...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE...

.SYNOPSIS...
Issued at 247 AM PDT Sat Apr 20 2024

Slight warming trend across the interior through Monday with
diminishing marine influences near the coast. Potential
drizzle/light rain chances mid-to-late next week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 247 AM PDT Sat Apr 20 2024

Expecting patchy coastal drizzle in the favored upslope regions
this morning with conditions improving by late morning. This is as
the marine layer remains around 1,000 feet in depth and will mix
out by the afternoon. Inland temperatures are expected to reach
the mid-to- upper 70s with coastal areas in the low 60s to low 70s
this afternoon. Winds will be on the increase by this afternoon
and will become breezy with northwest gusts between 25-35 mph near
the coast, the coastal hills, and higher peaks across the region.
Overnight, temperatures will largely cool into the upper 40s to
lower 50s.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 247 AM PDT Sat Apr 20 2024

Sunday and Monday will continue to be warm inland with
temperatures more likely to reach the lower 80s across the
interior. Meanwhile, coastal areas will peak in the low 60s to low
70s as the marine influence begins to diminish. By Tuesday,
conditions cool as a well- advertised upper level low approaches
and moves through the region. Cooler, unsettled weather will
continue through late week with increased cloud cover and
potential for light rainfall. Most likely scenario will be drizzle
near the coast and in the hills with possible light rain
elsewhere. &&

.AVIATION...
(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.

&&

.MARINE...
(Today through Thursday)
Issued at 247 AM PDT Sat Apr 20 2024

Northerly winds build into the afternoon today to become fresh to
strong across much of the waters through early Monday morning.
Gale force gusts are expected over the far northern outer waters
in this same time period, but begin to diminish late Sunday night.
Northwest swell builds Sunday 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 upcoming work week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes
     to Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 9 PM PDT Sunday
     for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

     Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Sunday
     for Pt Arena to Pt Reyes 10-60 NM.

     Gale Warning from 3 AM to 9 PM PDT Sunday for Pt Arena to Pt
     Reyes 10-60 NM.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PDT Sunday
     for Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...AC
MARINE...AC

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