146
FXUS66 KMTR 080946
AFDMTR

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

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

&&

.UPDATE...
Issued at 853 PM PDT Fri Jun 7 2024

The short term forecast is in good shape with just some minor
tweaks to overnight wind grids for some of the East Bay
Hills/Mountains, as well as across coastal waters (including the
northern part of the San Francisco/San Pablo Bay areas).

Flow this evening along the shoreline remained quite brisk,
especially along the Marin Headlands up toward Bodega Bay. In
fact, the Bodega Bay Profiler indicates around 35 knots of flow
around 1km. Whether or not this momentum mixes down to the surface
is a little uncertain, however, some of the short-term guidance
(e.g., HRRR) suggests this is a possibility. Winds across some of
the coastal waters---from Bodega Bay down through the Golden Gate
Gap were adjusted upward to the 75th NBM percentile. Winds appear
that they`ll channel through the Golden Gate Gap and accelerate
through portions of the SF and San Pablo Bays, as well as the west
Delta. East Bay Hills and Mountains may also be recipients of
this accelerated flow. The 75th percentile NBM numbers translate
to 20 to 30 mph wind gusts later tonight into the pre-dawn hours
on Saturday morning. The impact will be rough boating conditions
for small craft as well as an increased potential for any loose
outdoor articles (trash cans, lawn furniture) to be blown about in
the wind.

The rest of the forecast remains in good shape and updated
products have been transmitted.

&&

.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...
(06Z TAFS)
Issued at 1127 PM PDT Fri Jun 7 2024

MVFR and IFR CIGs are moving inland affecting most of the TAF
sites overnight and into Saturday morning with some areas along
the coast and in the Monterey seeing CIGs into Saturday afternoon.
Pockets of haze look to continue to affect the region through much
of Saturday in spite of moderate to breezy winds through the
afternoon and evening. Winds reduce into Saturday night as stratus
moves slightly inland once again.

Vicinity of SFO...MVFR lasts through the late morning. Winds stay
moderate through the night and begin to increase into Saturday
afternoon as CIGs dissipate, with gusts peaking around 25 kts.
Portions of the SF Bay may still be affected my reduced
visibility from haze, but it becomes less likely into the
afternoon. Expect winds to reduce in the late evening, but stay
moderate through Saturday night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR-LIFR CIGS are expected through he
late morning before CIGs lift to MVFR levels into the afternoon
before dissipating. Winds stay light to moderate overnight with
some pockets of mist and drizzle affecting the terminals. Winds
increase in the mid afternoon as VFR returns, but haze could still
affect local visibility. Weaker winds and lower clouds return
Saturday evening.

&&

.MARINE...
(Today through Thursday)
Issued at 242 AM PDT Sat Jun 8 2024

Chances for patchy fog and light drizzle continue through  the
morning, within the Monterey Bay and along the Big Sur
Coast.Breezy to gusty northwesterly winds will develop over the
waters through the weekend. Significant wave heights build
throughout the weekend with wave heights peaking between 12 to 14
feet. Elevated wave heights and gusty conditions will create
hazardous conditions for small crafts that will continue through
the weekend and into the following work week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM this morning to 3 AM PDT Sunday
     for SF Bay N of Bay Bridge.

     Small Craft Advisory from 9 AM this morning to 3 AM PDT Monday
     for Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt
     Reyes 10-60 NM-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 3 AM PDT Monday
     for Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...AC
LONG TERM....AC
AVIATION...Murdock
MARINE...Murdock

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