Text Products for AFD Issued by MTR

Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
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FXUS66 KMTR 131548
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
848 AM PDT Sat Apr 13 2024

...New UPDATE...

.SYNOPSIS...
Issued at 339 AM PDT Sat Apr 13 2024

The rain band builds inland this morning, offering widespread rain
and breezy to gusty winds. Showers and storm chances last through
the day and into the night. Storm chances decrease overnight, but
showers linger into Sunday afternoon before dry weather returns.

&&

.UPDATE...
Issued at 848 AM PDT Sat Apr 13 2024

Low pressure that has been slowly creeping down the coast this
morning, bringing rainfall to our entire service area, is showing
signs of slight southeastward movement. This is giving just enough
push to kick the main frontal boundary through the Bay Area and
Central Coastal midday. While the steady rain will taper, we will
enter into showers and possible thunderstorms for the afternoon
and evening. This is a cooler air mass aloft, which means the
threat for convection is present. With Sea Surface Temperatures
(SST) in the 52-55 degree range, this could provide enough
instability over the coastal water to get convection going and
translate inland. We`ll be watching this closely through the day
and evening hours. Thunderstorms could bring localized gusty
winds, copious amounts of small hail, and rapid onset flooding. In
short, it will be an active afternoon. Stay ready.

&&

.SHORT TERM...
(Today and tonight)
Issued at 339 AM PDT Sat Apr 13 2024

The main rain band is moving inland along the cold front, bringing
moderate rainfall. The rain band will become less organized as it
continues to move inland, leading to more widespread rain but with
reduced rain rates. Shower activity lasts behind the front, with
weaker, but still breezy winds expected through the day. The cold
front`s parent low moves onshore and inland in the afternoon and
into the night, providing additional scattered showers and storm
chances.

Storm chances will peak around 30% into this evening and into the
early night, with the focus being off the coast of Santa Cruz Co and
the Monterey Bay.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 339 AM PDT Sat Apr 13 2024

Thunderstorm chances dissipate into early Sunday morning with
showers lingering into the afternoon before exiting.

Afterwards, a ridge pattern builds in quickly, allowing for dry
weather to return into next week. This will also put the region into
another warming trend with highs ranging from the 60s (along the
coast) to the 80s (in more interior areas) expected in the middle of
the work week and into the next weekend.

The longer term forecast models keep the ridge pattern in place
beyond next weekend, but the ridge shifts slightly east, allowing
for more onshore flow. This will cool temperatures, but still
prevent rain from returning to the forecast.

&&

.AVIATION...
(12Z TAFS)
Issued at 502 AM PDT Sat Apr 13 2024

Mix of alternating VFR and MVFR. Widespread showers moving inland
bringing light to moderate rainfall, MVFR CIGs, and drops in
visibility. Airports across the board have
been bouncing between VFR and MVFR conditions but MVFR conditions
are expected to prevail as the system moves onshore. After
frontal passage this afternoon, precipitation will become more
scattered and thunderstorm chances will increase (20-25% chance).
For now highest thunderstorm potential looks to be over the
coastal waters from 21-06Z, but will continue to monitor and
adjust the TAFs as needed. Gusty SW winds will continue through
most of the TAF period with winds peaking during the afternoon
hours. Towards the end of the TAF period, winds will start to
weaken with S to SW winds to prevail.

Vicinity of SFO...MVFR to continue through the mid morning before
returning to VFR. Widespread light to moderate rain will transition
to isolated showers by the late morning. Gusty S to SW winds will
continue into the evening. Thunderstorm chances (20-25%) increase
this afternoon so will continue to monitor and adjust the TAFs as
needed.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Widespread light to moderate rain has
reached the Central Coast and will continue into the early
afternoon. Isolated showers with some thunderstorm potential (20%)
will develop during the afternoon and continue overnight. Moderately
gusty S to SW winds will continue for most of the TAF period with
winds starting to weaken early tomorrow morning.

&&

.MARINE...
(Today through Thursday)
Issued at 339 AM PDT Sat Apr 13 2024

Breezy fresh to strong winds continue across the coastal waters
ahead of an incoming low pressure system and it`s cold front. The
occasional near gale force gust, particularly in the southern
coastal waters, cannot be ruled out. With this system, widespread
light to moderate rain will continue through Saturday morning
before  transitioning to a more scattered, convective
precipitation mode  by the afternoon. Thunderstorm potential
increases to 25 to 30%  Saturday afternoon and evening with
chances decreasing overnight  into Sunday morning. Moderate period
northwesterly swell will  continue to build through the waters
through Saturday before  beginning its abating trend Sunday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Sunday
     for SF Bay N of Bay Bridge.

     Small Craft Advisory until 3 AM PDT Sunday for Mry Bay-Pigeon Pt
     to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos
     to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt
     Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pt Arena to
     Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...BFG/Murdock
LONG TERM....Murdock
AVIATION...Kennedy
MARINE...RGass/Kennedy

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