605
FXUS66 KMTR 030007
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
507 PM PDT Sun Jun 2 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1254 PM PDT Sun Jun 2 2024

Cooler temperatures hang on through Monday with breezy daytime winds
and marine layer stratus overnight. Tuesday sees a dramatic warmup
with a Heat Advisory in effect for the inland areas through
Thursday. Temperatures will moderate towards the latter part of
the week.

&&

.SHORT TERM...
(This evening through Monday)
Issued at 1254 PM PDT Sun Jun 2 2024

Coastal stratus lingers over the western San Mateo Peninsula, with
some cloud cover slipping through the San Bruno Gap, and in the
southern Monterey Bay region. Expect the remaining cloud cover over
the SF Bay region to dissipate through the rest of the afternoon and
brief, if any, clearing for the coastal regions. Stratus returns
inland tonight with the potential for gloomy skies through Monday,
as the fringes of a cold front that impacts the Pacific Northwest
come through the region. High resolution model output is showing
some chance (10-20% PoP) for showers in the Sonoma coastal ranges,
and coastal drizzle elsewhere, but accumulations are expected to
remain very light, up to a few hundredths of an inch at most.

Northwest winds are picking up around the region and gusts will top
out at 20 to 30 miles per hour across the gaps and passes. These
winds are expected to diminish tonight before picking up again on
Monday. Today`s highs will be in the upper 50s to lower 60s along
the Pacific coast, the mid 60s to lower 70s in the Bayshore, and
generally in the upper 70s to lower 80s across the inland valleys.
The North Bay and southern Monterey County valleys will see highs
rising into the mid to upper 80s. Low temperatures tonight will
hover in the mid 50s to lower 60s, and Monday`s highs should be
similar to today`s, except in the North Bay where the frontal
influence will drop high temperatures to the upper 70s to around
80.

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 1254 PM PDT Sun Jun 2 2024

Tuesday sees a pattern change as a subtropical high building in the
eastern Pacific comes into the region, warming temperatures to well
above the seasonal averages. A Heat Advisory is in effect for
Tuesday through Thursday for the interior North Bay and East Bay,
and Wednesday through Thursday for the South Bay and interior
mountains of the Central Coast, where high temperatures rise into
the 90s to the lower 100s and lows hover in the low to mid 60s,
perhaps around 70 in the warmest locations. There`s still a fair bit
of uncertainty in how the warmth will translate to the coast, in
particular how the marine layer and onshore winds will impact
coastal temperatures. The current forecast calls for temperatures in
the upper 70s to lower 80s along the Bayshore and the mid 60s to
lower 70s along the Pacific coast.

Moderate HeatRisk is expected for the inland North Bay, the East and
South Bays, and the inland Central Coast through Thursday, meaning
that there`s a moderate risk of heat-related illnesses for sensitive
populations (children, the elderly, pregnant women, those with
certain medical conditions, or anyone working outside without
cooling or hydration). In addition, we`re also starting to see major
HeatRisk in some areas of the North Bay valleys and far eastern
Contra Costa county on Tuesday, corresponding to a major risk of
heat-related illnesses to anyone without effective cooling, adequate
hydration, or both. Here are some heat safety tips:

* Stay hydrated and drink plenty of fluids.
* Wear lightweight, light-colored clothing.
* Reduce time spent outdoors or stay in the shade.
* Never leave people or pets unattended in vehicles.
* Use sunscreen if going to the coast or the pool.

A gradual cooling trend is expected to begin later in the week as
the high starts to crawl towards the east, with the large scale
pattern hinting at a possible southerly wind reversal. By the
upcoming weekend, high temperatures are expected to moderate to the
low to mid 80s for the inland valleys and the upper 50s to mid 60s
closer to the coast.

&&

.AVIATION...
(00Z TAFS)
Issued at 442 PM PDT Sun Jun 2 2024

The TAFs are long this evening with strong winds, widespread
ceilings, and areas of low-level wind shear expected tonight. The
SFO-SAC gradient has decreased slightly from yesterday, but
remains healthy at 3.1 mb as of 23Z. Some sheltered sites will see
the surface winds decrease overnight, but the synoptic set up
will allow strong winds to persist at low flight levels. As such,
LLWS is likely to develop near a few terminals. It`s explicitly
mentioned in the TAF for STS and OAK, but remains possible
throughout the Bay Area. The other concern is MVFR-IFR stratus
overnight. The confidence is high that stratus will return, but
some uncertainty remains regarding the cloud base due to a
possible disruption in the marine layer as a weak disturbance
moves through Monday morning and flattens the ridge axis.

Vicinity of SFO...Strong westerly winds persist at SFO with gusts
into the mid-30 kt range. These winds will gradually decrease
through the evening hours, but sustained winds are expected to
reamin above 12 kt all night. Low MVFR ceilings are expected to
develop overnight at both SFO and OAK. There is a 30% chance for
ceilings to drop below 500 ft for a the few hours surrounding
sunrise.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MRY is already back to IFR ceilings after
a few hours of relief. SNS is not far behind and should have an
MVFR ceiling develop around 03Z, although this may be optimistic
as the current visible imagery shows the low clouds spreading
faster than expected. While the TAFs don`t show it yet, there is
an increasing chance for ceilings to drop below 500 ft in the
morning. The current HREF guidance puts the probability around 40%
for both MRY and SNS. The visibility is also subject to drop
overnight, but with moderate surface winds, ceilings are expected
to be the limiting factor for flight conditions during the TAF
period.

&&

.MARINE...
(Tonight through next Friday)
Issued at 442 PM PDT Sun Jun 2 2024

The gradient between subtropical high pressure over the Pacific
and lower pressure over the Intermountain West is maintaining a
fresh to strong NW breeze. Buoys are reporting wind gusts as high
as 30 kts, on an increasing trend this evening. These conditions
will last well into the night. Moderate wave heights will persist
through Monday night before rough seas arrive mid-week.

&&

.CLIMATE...
Issued at 127 AM PDT Sat Jun 1 2024

Record high temperatures at the long term climate stations for
June 4th and 5th:

Station             June 4th             June 5th

Santa Rosa          98 in 1949           102 in 1926
Kentfield          101 in 1981           102 in 1926
Napa               102 in 1981           105 in 1903
Richmond            90 in 1955            86 in 1983
Livermore          105 in 1960           104 in 1926
San Francisco       92 in 1949            95 in 1883
SFO Airport         92 in 1955, 1949      89 in 1972
Redwood City       100 in 1981            97 in 2002, 1972
Half Moon Bay       71 in 1955            74 in 1958
Oakland downtown    96 in 1981            87 in 2002
San Jose            98 in 1904           100 in 1926
Salinas Airport     92 in 1949            87 in 1949
King City          102 in 1981, 1957     105 in 1926

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 8 AM Tuesday to midnight PDT Thursday night
     for CAZ503-504-506-510-515.

     Heat Advisory from 8 AM Wednesday to midnight PDT Thursday night
     for CAZ513-514-518.

PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay-
     Pigeon Pt to Pt Pinos 0-10 nm-SF Bay N of Bay Bridge.

     Small Craft Advisory from 3 PM to 9 PM PDT Monday 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-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory from 3 PM Monday to 9 AM PDT Tuesday 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 from 3 PM Monday to 3 AM PDT Tuesday for
     Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 3 AM PDT Tuesday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Flynn
MARINE...Flynn

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