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000
FXUS66 KMTR 101740
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1040 AM PDT Wed Apr 10 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 118 AM PDT Wed Apr 10 2024

Warm temps continue through Thursday with afternoon highs 10-15
degrees above seasonal normals. Transition day set for Friday as
the next system moves in, bringing widespread wind and rain, as
well as a slight chance for thunderstorms for the Central Coast
Saturday.

&&

.SHORT TERM...
(Today and tonight)
Issued at 118 AM PDT Wed Apr 10 2024

Warmest day of the week so far on tap today as the broad ridge
sets up over the West Coast. Afternoon temps will largely be in
the 70s across the area, with a few inland locations making it
into the lower 80s. Areas along the coast will remain in the mid-
to- upper 60s. There is a slight chance of some high clouds
spoiling the high temps just a bit and keeping some locations a
couple of degrees cooler than the current forecast. However, even
at a couple of degrees cooler, it will still be the warmest that
we`ve seen in several months. There`s a minor heat risk,
particularly for sensitive groups (elderly and infants). Be sure
to never leave children or pets in unattended vehicles. If you`re
working or playing outdoors, be sure to hydrate with plenty of
water.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 118 AM PDT Wed Apr 10 2024

Another warm day Thursday with temps near to a couple of degrees
cooler than today. However, it was noted that the progression of
the incoming system has slowed slightly, which resulted in
nudging temps slightly upwards for Thursday. If the system slows
even further, high temps Thursday will need to be adjusted higher,
which may result in moderate Heat Risk for inland valley
locations. With a slower moving trough, more and more of the area
could remain rain-free through at least Friday afternoon (though
clouds will increase). The exception to this will be parts of the
North Bay (near and north of a Bodega Bay to Cloverdale line).
While the current forecast advertises around a 20-30 PoP late
Friday into Saturday, the more probable area for rainfall (closer
to 50%) will be across the North Bay during the daylight hours. As
the upper level low churns and drops southward through the pre-
dawn hours on Saturday, rain chances will fill in from north to
south.

As of this issuance, it appears that most of the rain will fall
during the Saturday morning time frame. Overall amounts and
intensities have not changed much from the previous forecast, with
1-2" for the Santa Lucia and Santa Cruz Mtns, 0.5-1" elsewhere,
and 0.25-0.5" for inland rainshadowed valleys. Additionally, there
does appear to be a hint of instability Saturday afternoon.
Depending on the arrival time and setup location of the surface
low, there is the potential for thunderstorms Saturday afternoon
into the evening, particularly from the Santa Cruz Mtns southward
along the Central Coast.

Forecast uncertainty continues through Sunday as the range of
solutions widens. If the upper low quickly translates eastward,
then morning rain showers will yield to improving conditions in
the afternoon. However, if the upper trough continues to amplify
(which would be more in line with the current trends), then there
will be a potential that showers and thunderstorms would linger
later in the afternoon. Stay tuned for updates as the forecast
still exhibits a degree of variability for the upcoming weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1014 AM PDT Wed Apr 10 2024

Currently VFR at all terminals. All terminals are forecast to see a
reduction in flight category overnight as high pressure is allowing
for a compressed/shallow marine layer, confidence is highest at
terminals directly adjacent to the coast. Overall forecast trend has
been lower ceilings and visibilities for more terminals.

Vicinity of SFO...Currently VFR with breezy offshore flow. Winds
will be breezy out of the west this afternoon and evening before
diminishing overnight. Confidence is increasing that the terminal
will see a reduction of flight category tomorrow morning, the TAF
has MVFR for now, but later TAF cycles may trend more towards IFR as
that is the way that the overall forecast is trending. Winds will be
breezy out of the west again tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with breezy northwesterly
flow at MRY and VFR with breezy drainage flow at SNS. Winds will be
breezy out of the northwest this afternoon before becoming light
overnight. Confidence is moderate-high that MRY will see IFR
conditions overnight. Confidence is lower for SNS because if
drainage winds overnight are too strong, this will inhibit fog
development and if the marine layer is too shallow, it will not
reach SNS.

&&

.MARINE...
(Today through Monday)
Issued at 1014 AM PDT Wed Apr 10 2024

High pressure over the Eastern Pacific Ocean will dominate the
forecast through tomorrow, allowing for fair weather and fresh to
strong northerly breezes to prevail over the coastal waters. Long
period northwesterly swell will continue to build through the
waters  through today before beginning its abating trend tomorrow.
Come  Friday, a deep upper-level low will bring renewed chances
for rain,  gusty winds, thunderstorms, and hazardous seas to the
coastal waters  through the weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM Thursday to 9 AM PDT Friday for
     Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas
     0-10 nm.

     Small Craft Advisory until 9 AM PDT Friday for Pt Arena to Pt
     Reyes 10-60 NM.

     Small Craft Advisory from 3 PM this afternoon to 9 AM PDT Friday
     for Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Sarment
MARINE...Sarment

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