-- Discussion containing changed information from previous version are highlighted. --
659
FXUS66 KMTR 222005
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
105 PM PDT Sat Jun 22 2024

...New SYNOPSIS, SHORT TERM, LONG TERM...

.SYNOPSIS...
-- Changed Discussion --
Issued at 105 PM PDT Sat Jun 22 2024

Hot temperatures peak this afternoon with a Heat Advisory in effect
through the evening for the interior regions with a moderate risk of
heat-related illnesses. Temperatures moderate through the early part
of next week, but remain warm across the interior.
-- End Changed Discussion --

&&

.SHORT TERM...
-- Changed Discussion --
(This evening through Sunday)
Issued at 105 PM PDT Sat Jun 22 2024

A Heat Advisory remains in effect until 10 PM across the interior
where temperatures are forecast to reach into the mid 90`s to near
105 degrees this afternoon. This will result in Moderate HeatRisk
across these areas with temperatures gradually cooling this evening.
This means that there is a risk of heat-related illnesses for most
people sensitive to heat, including children, the elderly, pregnant
women, those working or living outside, and those with certain
medical conditions. Here are heat safety tips:

* Stay hydrated and drink plenty of water.
* 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.

Tonight, temperatures will generally cool into the mid-to-upper 50`s
for most locations away from the immediate coast with some upper
40`s in those locations. However, warm temperatures will persist
across the higher elevations where temperatures will only dip into
the upper 60`s to upper 70`s. Low clouds and/or fog will also return
to the region this evening, yet will penetrate less inland overnight
as high pressure continues to compresses the marine layer.

Temperatures on Sunday begin to cool slightly (especially across the
interior) as onshore flow increases and the marine layer deepens.
Thus, afternoon maximum temperatures on Sunday are expected to range
from the upper 80`s to mid 90`s across the interior with only
isolated pockets warming into the upper 90`s to near 100 degrees.
Cooler conditions will prevail near the coast with upper 50`s to
upper 60`s, 70`s just inland away from the immediate coastline, and
low-to-mid 70`s to low 80`s around the bayshore.
-- End Changed Discussion --

&&

.LONG TERM...
-- Changed Discussion --
(Sunday night through next Friday)
Issued at 105 PM PDT Sat Jun 22 2024

An area of mid-to-upper level moisture will move northward into the
region on Tuesday resulting in increased mid/upper level clouds. We
will need to watch this for any potential for high-based convection,
yet the treat remains very low as this time. By late week,
temperatures trend cooler across the interior in response to an
upper level trough impacting the region with increased onshore flow.

The latest CPC outlook continues to suggest temperatures near or
above seasonal averages, and precipitation at or below seasonal
averages (noting that at this point in the year, seasonal average
precipitation is very low) continue into the first days of July.
-- End Changed Discussion --

&&

.AVIATION...
(18Z TAFS)
Issued at 1055 AM PDT Sat Jun 22 2024

VFR across the board with stratus and MVFR-LIFR conditions returning
across portions of the Bay Area and Central Coast tonight. Moderate
confidence that stratus will reach OAK, SFO, MRY, and SNS but not
extend into STS, LVK, or SJC. Low to moderate confidence that
stratus will reach APC. For now, expecting similar stratus coverage
at APC tomorrow as seen today with NBM and HREF showing stratus
moving up the delta and reaching APC around 11/12Z. Breezy onshore
flow will return this afternoon before light northwest to, at times,
variable winds return overnight.

Vicinity of SFO...VFR becoming MVFR-IFR overnight. Stratus is
currently expected to reach SFO overnight but confidence is
currently moderate, bordering low to moderate. The main uncertainty
comes from the depth of the marine layer which is expected to
compress further tonight. Currently, the top of the marine layer is
around 1000 ft which allowed stratus to reach SFO this morning. If
the marine layer compresses closer to a depth of 500 ft, as
currently forecast, stratus coverage may be confined closer to the
coast/potentially not reach SFO. Weak northerly to northeasterly
winds will continue through the remainder of the morning before
moderate westerly to northwesterly return early this afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR becoming MVFR-LIFR overnight. Moderate
to high confidence that stratus will return overnight with low to
moderate confidence on timing. Stratus looks to return by late this
evening at MRY and during the early morning at SNS. For MRY, models
indicated cloud coverage may fluctuate between few/scattered and
broken/overcast roughly between 03-10Z with confidence increasing in
overcast conditions from 10Z onwards. Currently leaning towards
broken/overcast conditions prevailing from 03-10Z but cannot rule
out cloud coverage temporarily becoming more scattered. Onshore flow
continues with moderate afternoon winds becoming light and variable
overnight.

&&

.MARINE...
(Today through Thursday)
Issued at 851 AM PDT Sat Jun 22 2024

Strong, northwest winds with near gale force gusts possible
continue into the work week over the northern outer coastal
waters. Fresh to the occasional strong gusts remain possible over
the southern outer coastal waters and portions of the northern
interior coastal waters. Elevated wave heights between 10 to 12
feet continue over the northern outer waters with significant wave
heights expected to diminish below 10 feet by the middle of the
work week. Conditions hazardous to small crafts will remain
possible through the middle of the work week across the northern
outer coastal waters. Light southerly swell continues to move
through the waters, accompanied by moderate NW swell through the
beginning of next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 10 PM PDT this evening for CAZ504-510-
     513>518.

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

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
     to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass/DialH
AVIATION...Kennedy
MARINE...Kennedy

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