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000
FXUS66 KMTR 031955
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1255 PM PDT Sat Jun 3 2023

...New SYNOPSIS, SHORT TERM, LONG TERM, AVIATION, MARINE...

.SYNOPSIS...
Issued at 1245 PM PDT Sat Jun 3 2023

Warm and dry conditions will persist into Sunday as high pressure
remains aloft. Unsettled conditions return for the first half of
the upcoming week as a low pressure system approaches the region.
This will result in cooler temperatures and potential for showers
and thunderstorms from Monday into Tuesday.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 1245 PM PDT Sat Jun 3 2023

The short-wave ridge aloft and compressed marine layer near the
surface will continue to dominate through the remainder of the
weekend. As such, the first will lead to a continued warming trend
into Sunday with widespread 80s across the interior. With Sunday
afternoon expected to see peak warming aloft, there is a 20%- 60%
probability of exceeding 90 deg F in the region`s typical "hot
spots". To the latter, stratus will return to coastal areas mainly
south of the Golden Gate late tonight and spread inland into the
Salinas Valley early Sunday morning. The low clouds will then
dissipate and retreat back to the coast through the morning and
into early afternoon. Thus, temperatures will remain cooler near
the coast with afternoon highs peaking generally in the 60s to
lower 70s. Also worth noting, it does remain very dry above the
marine inversion with relative humidity bottoming out between
10%-20% at elevations above about 3,000 feet.

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 1245 PM PDT Sat Jun 3 2023

The aforementioned ridge will dissolve and become quickly
replaced by broader troughing over the eastern Pacific as we move
into the upcoming work week. Meanwhile, confidence continues to
increase with regards to a mid/upper level cut-off low developing
off of the southern California coast. As this occurs, mid-level
moisture will be advected counter-clockwise around the system.
Precipitable water values of 0.75"-1.00" will advect across
central California as the low pressure system gradually shifts
northward toward the Central Coast from Monday into Tuesday. This
will result in a 15-35% probability of rain showers over much of
the region (greatest potential over the Central Coast).
Additionally, forecast confidence continues to increase regarding
the atmosphere becoming more unstable during this time leading to
a 15-20% probability of thunderstorms from Monday afternoon into
Tuesday. For the most part, measurable precipitation will be light
for most and generally be around 0.10" or less. That said,
stronger convection that does develop will produce brief downpours
brining up to 0.25- 0.50" of rainfall. Details will continue to
be fine tuned in the coming days as the event draws nearer and
into the scope of the higher resolution models. The main message
for Monday and Tuesday will be to keep a raincoat/umbrella handy
and to take shelter if you hear thunder or see lightning.
Remember, if you can hear thunder, then you`re close enough to get
struck by lightning!

Otherwise, the lingering low pressure near and/or over California
will keep daytime temperatures below seasonal averages with 50s and
60s near the coast and 60s to 70s inland for at least the first half
of the week. It will also feel muggy at times given the anomalously
high moisture being advected over the region. By late week, the
eventual inland shift of the cut-off low will occur resulting in a
slight warming trend and return of a more defined marine layer.
&&

.AVIATION...
(18Z TAFS)
Issued at 1255 PM PDT Sat Jun 3 2023

It`s VFR except for patchy stratus and fog /MVFR-IFR/ along the
immediate coast. Coastal stratus and fog /LIFR-IFR/ moving locally
inland tonight and Sunday morning, then mixing out by late Sunday
morning.

Vicinity of SFO...VFR. Afternoon and evening west wind gusts near
20 knots, wind decreasing to 5 to 10 knots tonight. West wind near
15 knots Sunday afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR except patches of stratus and fog
/MVFR-IFR/ around the Monterey Bay. Stratus and fog /LIFR-IFR/
moving inland tonight and Sunday morning, mixing out by late
Sunday morning.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 1245 PM PDT Sat Jun 3 2023

Gale force gusts continuing across the northern outer waters and
along the far northern coast through late this evening and early
Sunday morning. Expect generally a strong northwest breeze to
continue through the weekend with windiest spots north of Pigeon
Point. These stronger winds are generating steep wind waves that
may be hazardous to small craft. Meanwhile, moderate to longer
period southerly swell (14 to 17 seconds) persists in the
background through the weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for PZZ535-560.

     Gale Warning until 9 PM PDT this evening for PZZ540.

     Small Craft Advisory until 3 AM PDT Sunday for PZZ545-565.

     Gale Warning until 4 PM PDT Sunday for PZZ570.

     Small Craft Advisory until 9 AM PDT Sunday for PZZ575.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Canepa
MARINE...Canepa

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