763
FXUS66 KMTR 271803
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1103 AM PDT Sun Apr 27 2025

...New AVIATION...

.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.

&&

.UPDATE...
Issued at 904 AM PDT Sun Apr 27 2025

Drizzly conditions and light rain showers continue across the Bay
Area and Central Coast through this afternoon. A look at 36 hour
precipitation totals shows the Santa Lucia Range as the big winner
with between 0.3"-0.6" observed from this event. Elsewhere, totals
ranged from a few hundredths of an inch to two tenths of an inch
with locally higher amounts across the elevated terrain. Additional
rainfall today is expected to be light, amounting to only a few
hundredths of an inch.

&&

.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 fr0ontogenesis 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...
(18Z TAFS)
Issued at 1103 AM PDT Sun Apr 27 2025

Impacts of upper low moving to our east is still impacting the
terminals and airspace with extensive low clouds over the region
this morning with bases roughly 1500-2500 feet. Radar showing
lingering showers from Santa Clara Valley southward through
Monterey county with KMRY the most likely to hold onto lingering
showers or drizzle through early afternoon. Expect gradual
clearing and lifting of cloud bases after 21z this afternoon with
light nw winds. Enough lingering moisture and cyclonic flow for
low clouds to stay in place overnight with higher confidence for
skies clearing with VFR conditions beyond 18z Monday.

Vicinity of SFO...Improving conditions after 21z with cigs mixing
and lifting before returning overnight through Monday morning.
Higher confidence for clearing skies and a return of VFR after 18z
Monday.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Lingering showers and drizzle through
early afternoon. High confidence for MVFR cigs to return overnight
through Monday morning with VFR conditions likely after 18z Monday.

&&

.MARINE...
(Today through Friday)
Issued at 904 AM PDT Sun Apr 27 2025

Northwest winds will be gusty due to a high pressure system
building over the offshore waters through early week, winds will
also result in hazardous seas across the outer coastal waters.
From mid to late week surface high pressure will gradually weaken
while an upper  level trough will move in from the northwest. By
late week another upper level trough from the northwest will
approach the coastal  waters and bays.

&&

.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 Pt Arena to Pt
     Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory from 3 PM to 9 PM PDT Monday for Pt Arena
     to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

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

     Small Craft Advisory until 9 PM PDT Monday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...RW
MARINE...RW

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