197
FXUS66 KMTR 270739
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1239 AM PDT Sun Apr 27 2025

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

.SYNOPSIS...
Issued at 1205 AM PDT Sun Apr 27 2025

Light showers focused on the Central Coast continue through the
morning. A pattern change will bring warmer and drier weather
through the work week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 1205 AM PDT Sun Apr 27 2025

KMUX shows light rain falling throughout the majority of Monterey
County. This includes the Big Sur International Marathon course
where runners will begin loading shuttles in just 3 hours or so. A
nearly cut-off low pressure system has drifted towards the CA/NV
border, and the Bay Area is now firmly in the back-side
environment. The dynamics are a bit unusual, however. A moisture
plume is keeping the PWAT above 150% of normal, despite the
northerly winds which veer offshore with height. There is also
some indication of frontogenesis with warm air advection present
at 700 mb. Thunderstorms never materialized on Saturday, and the
chance continues to diminish. All signs point to the rain tapering
off through the morning with skies starting to clear in the
evening. Temperatures will remain in the 50s and 60s due to
overcast skies and a lingering cold air mass. There is a good
chance for fog during the Monday commute as building high pressure
causes the skies to clear over the still cool and humid surface.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 1205 AM PDT Sun Apr 27 2025

After any fog mixes out late Monday morning, it will turn into a
beautiful day with plenty of sunshine and temperatures up to 10
degrees warmer than the weekend. The good weather will continue
through the work week as a ridge builds over the west coast. Mid
week looks to be the warmest with inland highs in the mid to upper
70s. A shallow marine layer will keep coastal areas in the low
60s, but the coastal clouds shouldn`t last all day. Most guidance
indicates the pattern will become unsettled again by Friday or
Saturday as some combination of a cut-off low and/or mid-level
trough bring back overcast skies, cooler temperatures, stronger
wind, and a slight chance for rain next weekend.

&&

.AVIATION...
(06Z TAFS)
Issued at 1013 PM PDT Sat Apr 26 2025

MVFR conditions and westerly winds to prevail through most of the
TAF period. A late return to low-end VFR is expected by tomorrow
afternoon at all but the Monterey Bay terminals. After the rain band
goes over the Monterey Bay terminals late tonight, light rainfall
will become scattered in nature with the uncertainty lying in the
location and timing. If the upper-level low exits quicker to the
east, then most terminals will remain dry after 12Z, but if it is
slower, that can be delayed to 18Z. Nonetheless, rain showers can be
expected in the region with the primary impact being wet runways.

Vicinity of SFO...MVFR ceilings to prevail through tomorrow morning
with a slow improvement to VFR expected. Westerly winds will prevail
through the TAF period.

SFO Bridge Approach...The San Mateo Bridge Approach will be slower
to clear of MVFR conditions and rain showers tomorrow morning.

Monterey Bay Terminals...MVFR conditions and westerly winds to
prevail through the TAF period. Light rain will become scattered in
nature by the early morning hours of Sunday.

&&

.MARINE...
(Tonight through next Friday)
Issued at 908 PM PDT Sat Apr 26 2025

Light rain showers will continue through Sunday morning with a
less  than 10% chance for thunderstorms which would pose the risks
of  lightning, small hail, and locally gusty winds and heavy
rainfall.  Strong northwesterly breezes and rough seas will
continue for the  outer waters, inner waters and bays can expect
moderate seas and  moderate northwesterly breezes with strong
gusts.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for Mry Bay.

     Small Craft Advisory until 3 AM PDT Monday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt
     Reyes 10-60 NM.

     Small Craft Advisory until 9 PM PDT this evening for Pt Reyes to
     Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 9 PM PDT this
     evening for Pigeon Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 3 AM PDT Monday
     for Pt Pinos to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Sarment
MARINE...Sarment

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea