556
FXUS66 KMTR 081803
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1103 AM PDT Sat Jun 8 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 242 AM PDT Sat Jun 8 2024

Cooler temperatures and breezy afternoon onshore winds last
through the weekend. Another warm up is expected towards the
beginning of next week.

&&

.SHORT TERM...
(Today and Sunday) Issued at 242 AM PDT Sat Jun 8 2024

Temperatures at this time of night are running anywhere
from 5 to 10 degrees cooler than this same time yesterday for inland
regions, with areas closest to the coast and covered by stratus
running about 1 to 2 degrees warmer than yesterday. Looking at
current air temperatures across the CWA, the spread between the
coast and inland areas is very little, with largely uniform
temperatures in the mid 50s. That being said, the cool off continues
today as a weak trough moves through. High temperatures generally
reach into the low to mid 80s for most inland locations today,
perhaps a few upper 80s in the favored warm spots in the far
southern Salinas Valley, and northern Sonoma and Napa counties. High
temperatures at the coast will reach into the upper 50s and low 60s.
Breezier onshore winds will return this afternoon, with gusts
nearing the 25 mph range in the East Bay and Delta region, but will
ease into the nighttime as the gradient eases. Largely a rinse and
repeat for Sunday.

One thing worth noting for today`s forecast is the inclusion of haze
in the forecast for select locations. With recent ridging and
compression of the atmosphere, particulate matter including smog,
smoke, dust, and sea salt (the latter being lofted up by winds) have
largely been confined close to the surface with nowhere to go. A
look at area METAR reports the past few days shows reduced
visibilities in the early evenings and reports of haze. Therefore
have included the potential for haze in today`s forecast. However,
expectations are that as the weak trough moves through later today,
this allowance for rising air and breezier onshore flow should help
to move particulate matter out of the region, therefore decreasing
the appearance of hazy skies into Sunday.

&&

.LONG TERM...
(Monday through Friday) Issued at 242 AM PDT Sat Jun 8 2024

Starting Monday, another warm up begins as slight ridging
develops once more. High temperatures reach into the high 80s and
lower 90s for inland regions, with the warmest spots achieving
temperatures in the mid 90s. Tuesday, temperatures increase a few
degrees more with mid to upper 90s expected for the warmest spots.
A few spots reaching into the low 100s namely in the eastern most
portion of our CWA are not out of the question. Meanwhile,
temperatures at the coast will maintain in the mid 60s. Warm
temperatures persist into Wednesday, but begin to drop by a few
degrees.

Despite the warmer temperatures, NWS HeatRisk is currently largely
only in the minor category, impacting those extremely sensitive to
heat (ill, elderly, pregnant, or young children) as overnight low
temperatures in the mid 50s will provide good overnight relief for
all. Small pockets of moderate heat risk are possible in the warmest
areas nearest to the Central Valley. Nonetheless, its never a bad
idea to make sure you are staying adequately hydrated during times
of warmer temperatures, taking breaks in the shade if working
outdoors, and to check in on loved ones who perhaps fall into the
demographics of those most sensitive to heat. Additionally, if
planning to visit the coast or a body of water to cool off, make
sure you wear a life jacket, swim ideally near a lifeguard, and
be aware of the risks of cold water shock.

Towards Thursday of the week next week, high temperatures take a dip
and begin to cool off as troughing resumes. A cutoff low hanging off
the coast of southern California will lift out to our northeast,
inducing the cool-off. All for now, but stay tuned for updates as we
near the warming event. Have not issued any heat-related products at
this time.

&&

.AVIATION...
(18Z TAFS)
Issued at 1032 AM PDT Sat Jun 8 2024

Coastal stratus is eroding and VFR conditions will prevail through
the remainder of the day. Moderate SW winds will prevail in the
North Bay, with NW winds at SJC and westerly winds elsewhere.
MVFR-IFR stratus will return to most terminals overnight.

Vicinity of SFO...VFR under high clouds. WNW winds will be
moderate to strong this afternoon, and will remain fairly
consistent once they get started. The big question at SFO is if
ceilings will return overnight. The TAF keeps it clear for now,
but there is a 20-30% chance of a low MVFR ceiling in the early
morning hours Saturday, similar to what was observed this morning.
OAK has a better chance, and MVRF ceilings were included in the
TAF from 13-17Z Sunday.

SFO Bridge Approach...The bridge approach will likely stay clear
of low clouds, even if SFO and OAK develop ceilings Sun morning.

Monterey Bay Terminals...MVFR ceilings are lingering, but the
visible satellite loop shows they will soon break at both MRY and
SNS. VFR conditions are likely for about 9-12 hours before the
stratus returns this evening. GFSLAMP shows a 15% chance of LIFR
ceilings developing around 12Z at MRY, and with subtle
compression expected in the marine layer, the ceilings may drop
lower than they were this morning (OVC006). Otherwise, moderate
onshore winds will persist through the TAF period.

&&

.MARINE...
(Today through Thursday)
Issued at 1032 AM PDT Sat Jun 8 2024

The gradient between subtropical high pressure and lower pressure
over the SW US is supporting a moderate to fresh NW breeze. As the
high pressure slowly encroaches towards the coast, the pressure
gradient will tighten, causing the wind speed to increase through
the weekend. A fresh to strong NW breeze will persist through
next week with the potential for gale force winds by next weekend.
Significant wave heights will mostly be dominated by wind driven
waves, though there is a moderate NW swell and a low SW swell
mixed in.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for SF Bay N of Bay
     Bridge.

     Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

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

     Small Craft Advisory from 3 PM Sunday to 3 AM PDT Monday for Pt
     Pinos to Pt Piedras Blancas 0-10 nm.

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

&&

$$

SHORT TERM...AC
LONG TERM....AC
AVIATION...Flynn
MARINE...Flynn

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