559
FXUS66 KMTR 191211
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
511 AM PDT Sat Apr 19 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1201 AM PDT Sat Apr 19 2025

Fairly quiet weather is in store through the next several days,
with a modest warming trend through early next week. A pattern
change will bring cooler, cloudier conditions and a chance for
light rain late next week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 1201 AM PDT Sat Apr 19 2025

The marine layer has compressed to around 500 feet, and the low
stratus is confined mostly to the Bay Area coast. The marine layer
is a little deeper across the central coast, where the stratus is
filling the Salinas Valley. These clouds will clear in the
afternoon and the temperatures will be near normal, similar to
yesterday. A weak disturbance will arrive this evening, allowing
the marine layer to deepen. As a result, cloud cover will be more
extensive early Sunday morning. The offshore winds will also
weaken as the gradient relaxes. This will allow more low-level
moisture, and there could be patchy fog and even some drizzle
across the region.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 1201 AM PDT Sat Apr 19 2025

The disturbance will quickly move through Sunday, allowing
persistent zonal flow to become entrenched from Sunday afternoon
through Tuesday. This will bring fair weather with mostly clear
skies, gentle to moderate onshore winds, and high temperatures
above seasonal normal. The typical warmer inland areas have a
roughly even chance of breaking 80 degrees Monday. This warmer
weather will cause minor HeatRisk, which can be hazardous to those
extremely sensitive to the heat. Otherwise, this period will be
pretty nice.

Ensembles are now in good agreement that the pattern will change
mid week as a deep trough disrupts the subtropical high in the
eastern Pacific. This system will bring a cooler air mass from the
NW, causing surface temperatures to cool back below normal by
Friday. The strength and timing of this trough is still uncertain,
but it is looking more likely that some light rain will fall
Friday-Saturday.

&&

.AVIATION...
(12Z TAFS)
Issued at 510 AM PDT Sat Apr 19 2025

Widespread IFR and MVFR CIGS are affecting the region with LIFR/IFR
CIGS affecting the North Bay terminals as well as MRY. Pockets of
fog are also affecting some of the valleys, specifically at STS.
Cloud cover begins to erode in the late morning, but remains on the
coast, with HAF seeing CIGs through the TAF period. Winds stay light
to moderate through the morning, and increase into the afternoon
before reducing again over the evening. IFR CIGS build along the
coast and begin to push inland Saturday evening with some terminals
falling to LIFR into the late night and early Sunday as CIGs become
widespread once again.

Vicinity of SFO...Light winds and moments of MVFR CIGS linger into
the late morning. Skies clear before moderate west winds expected
for the afternoon and into the night. These winds will reduce
overnight, becoming light as IFR CIGs fill over SFO.

SFO Bridge Approach...Expect CIGs to stay more consistent than at
SFO and last until the late morning. IFR CIGS will arrive later into
Sunday morning than SFO.

Monterey Bay Terminals...IFR CIGS and light winds last into the late
morning before CIGs retreat back into the Monterey Bay and moderate
northwest winds build. Winds reduce into the early evening with IFR
CIGs moving inland and filling over the terminals. Pockets of fog
look to form in the late night and MRY looks to fall to LIFR by
early Sunday.

&&

.MARINE...
(Today through Thursday)
Issued at 510 AM PDT Sat Apr 19 2025

Breezy to gusty winds increase through the day specifically over
the northern outer waters, as a weak cold front approaches from
the north. The increasing winds will result in a building
northerly fresh swell. Gusty winds spread across the waters into
the next work week and look to remain through the week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM Sunday to 3 AM PDT Monday for Pt
     Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt
     Reyes 10-60 NM.

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

&&

$$

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Murdock
MARINE...Murdock

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