612
FXUS66 KMTR 152323
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
423 PM PDT Wed May 15 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1232 PM PDT Wed May 15 2024

Quiet weather will continue with a persistent marine layer through
the forecast period. Morning clouds and mist will clear in the
afternoon. Despite the clearing, coastal areas will remain in the
cool marine air, keeping highs in the 60s. Inland and high
elevation areas will reach the 70s and 80s each afternoon.

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 1232 PM PDT Wed May 15 2024

The stratus is clearing on schedule and should return this
evening. The marine layer is currently around 1500-2000 ft deep
as identified by a sharp low level inversion on the 12Z sounding
and current observations from area profilers. NAM point soundings
suggests the marine layer will compress to around 800 ft over the
next 18 hours. This will cause a lower cloud deck Thursday, with
more areas impacted by mist and fog. It will also limit the extent
of the marine layer, keeping more inland areas in the sun and the
warmer continental air mass. Otherwise, the weather pattern is
pretty stable with mild temperatures and a weak pressure gradient
producing light to gentle winds.

&&

.LONG TERM...
(Thursday night through next Thursday)
Issued at 1232 PM PDT Wed May 15 2024

The current pattern will remain fairly stable through Sunday. Low
clouds in the morning along the coast and adjacent valleys will
clear by mid-day. High temperatures will be stuck in the 60s for
areas in the marine layer, and in the 80s for the warmest inland
valleys. Lows will mostly be in the 50s. By early next week, the
global models agree that the jet stream, which has been running
E-W across the PNW, will become meridional, with a long wave
trough taking aim at California. This trough pattern will persist
through next week, bringing a few weak cold fronts, some cooler
weather, periods of stronger NW winds, and even the chance for
some very light rain, although the air mass looks pretty dry.

&&

.AVIATION...
(00Z TAFS)
Issued at 423 PM PDT Wed May 15 2024

Satellite imagery shows MVFR-IFR stratus across the immediate coast
and into portions of the Monterey Bay region. Stratus is expected to
flow inland through the overnight hours and retreat to the immediate
coastal region on Thursday morning. Some lower visibilities are
possible tonight as the marine layer slightly compresses. STS
currently has BR within the TAF but model output suggests that fog
is definitely possible. Breezy northwest flow will continue through
the evening hours, returning to the region on Thursday afternoon.

Vicinity of SFO... VFR through the evening with breezy and gusty
northwest winds. IFR-MVFR stratus develops after midnight, with OAK
seeing stratus development earlier in the evening. Stratus expected
to clear later Thursday morning, with breezy westerly winds
developing again in the afternoon and evening hours. Some model
output is suggesting that an early return of stratus is possible,
but confidence is too low to include in the TAF at this time.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... MVFR stratus lingers across the coastline
and is flowing into the inland areas. Stratus will expand inland
through the evening into the night, as ceilings decrease to IFR-
LIFR. Clearing will begin later Thursday morning for the interior,
with the coast seeing brief if any clearing during the afternoon.
Breezy onshore winds continue through the evening before resuming
Thursday afternoon.

&&

.MARINE...
(Tonight through next Monday)
Issued at 423 PM PDT Wed May 15 2024

Surface high pressure over the Eastern Pacific continues to
weaken, with moderate to fresh northwesterly breezes prevailing,
and  significant wave heights abating through Thursday. By Friday
the surface high strengthens and moves east, increasing
northwesterly breezes and building wave heights through the
weekend and into  next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM Thursday to 3 AM PDT Friday for
     Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...DialH
MARINE...DialH

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