332
FXUS66 KMTR 261544
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
844 AM PDT Fri Jul 26 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 305 AM PDT Fri Jul 26 2024

Temperatures cool down more significantly beginning today with
below average temperatures to persist through mid next week. Some
potential for light drizzle along the coast Friday into Saturday
and Saturday into Sunday.

&&

.UPDATE...
Issued at 843 AM PDT Fri Jul 26 2024

The marine layer appears to be rapidly deepening this morning and is
expected to do so throughout the upcoming weekend. This will lead to
a cooling trend as onshore flow increases both today and more so
tomorrow. Look for stratus to peel back to the coast mid-to-late
morning with more widespread coverage tonight. The ongoing forecast
remains on track at this time with no updates anticipated this
morning.

&&

.SHORT TERM...
(Today and tonight)
Issued at 305 AM PDT Fri Jul 26 2024

Temperatures are expected to be significantly cooler today as an
upper level low moves inland and allows for upper level troughing to
deepen over the Western US. As a result, seasonal to below average
temperatures will persist through mid next week. Inland highs today
will primarily be in the 80s but favored hot spots across the North
and East Bay may see temperatures reach the low 90s. Closer to the
coast high temperatures will peak in the 60s directly along the
coastline and upper 60s to 70s slightly inland from the coast.
Interior Monterey and San Benito counties will continue to be warm
today with highs in the upper 90s to low 100s. Gusty onshore winds
between 20-35 mph are expected during the afternoon/evening as winds
funnel into the San Francisco Bay and through gaps and passes.

The Fort Ord Profiler shows a fairly compressed marine layer with a
depth of ~1000 ft. This will limit inland stratus coverage and keep
stratus confined closer to the coast. As upper level troughing
intensifies the marine layer will be able to deepen which, in
combination with stronger onshore flow, will allow for increased
moisture transport inland and more widespread stratus coverage. The
NBM and HRRR both show some potential for drizzle overnight Friday
into Saturday. Accumulations will generally be light with totals
ranging from a trace to a few hundredths of an inch directly along
the coast and along areas of elevated terrain where upslope ascent

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 305 AM PDT Fri Jul 26 2024

Temperatures continue to cool Saturday and Sunday with widespread
70s to 80s expected inland and 60s to 70s expected closer to the
coast. Upper level troughing will continue to deepen over the
weekend which will help to keep temperatures cooler and contribute
to some slight potential for light drizzle. Overnight Friday into
Saturday and Saturday into Sunday, decent low level moisture at
850mb and 700mb will support the development of light drizzle to
light rain along the coast and in areas where upslope ascent is
favored. Both the NBM and the HRRR pick up on light coastal drizzle
overnight this weekend with some potential for light showers over
the marine environment. The NBM is showing very light precipitation
totals along the coast and bay shoreline with totals ranging from a
trace to a few hundredths of an inch.

The upper level pattern will become more zonal by early next week
which will allow for temperatures to warm slightly. In general,
temperatures are expected to gradually increase a few degrees each
day beginning Monday but high temperatures will still remain below
average through mid-week. By mid to late next week, a little more
uncertainty enters the forecast in regards to how fast high
temperatures will warm up again. Ensemble guidance indicates ridging
will start to build over the Western US by mid to late next week but
cluster analysis indicates that it is less certain where exactly the
ridge will set up. Temperatures could be slightly warmer depending
on if the ridge is centered more directly over the West Coast vs
temperatures could be slightly cooler if the ridge is centered to
the east of the coast. Regardless, it is looking likely that above
average temperatures will return with the current forecast and the
CPC 8-14 day outlook both in support of slightly above average
temperatures returning by the first week of August.

&&

.AVIATION...
(12Z TAFS)
Issued at 430 AM PDT Fri Jul 26 2024

Compressed marine layer this morning with IFR/LIFR cigs along
isolated coastal areas. Expecting effective clearing this morning
by 16-17Z for terminals that do develop cigs. Highest confidence
is right along the coast and Monterey Bay terminals. Confidence is
lower around the North Bay and SF Bay Area where terminals may see
brief cigs around sunrise. VFR through the day thereafter. High
confidence in a deeper marine layer tonight with MVFR/IFR cigs
affecting most terminals.

Vicinity of SFO...Low confidence in cigs developing at the
terminal this morning, though there remains a non-zero chance of
occasional stratus around sunrise. VFR through the day thereafter
with typical NW winds, breezy in the afternoon. Medium-high
confidence in cigs developing tonight with a deeper marine layer,
though timing may need to be adjust later for start time.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR/LIFR this morning before sunrise
under a compressed marine layer. Expecting the cigs and FG to mix
out by mid-to-late morning, VFR into the afternoon. Stratus looks
to hang around the coast most of the day. High confidence in the
return of MVFR/IFR cigs this evening.

&&

.MARINE...
(Today through Wednesday)
Issued at 843 AM PDT Fri Jul 26 2024

Moderate to fresh northwesterly breezes with strong gusts will
prevail through the forecast period. Significant wave heights will
continue to abate through the forecast period.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT
     Saturday for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt
     Piedras Blancas 0-10 nm-SF Bay N of Bay Bridge.

     Small Craft Advisory from 3 PM Saturday to 3 AM PDT Sunday for
     Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory from 3 PM to 9 PM PDT Saturday for Pigeon
     Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory from 9 AM Saturday to 3 AM PDT Sunday for
     Pt Pinos to Pt Piedras Blancas 0-10 nm.

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

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

     Small Craft Advisory from 9 PM Saturday to 3 AM PDT Sunday for
     Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

UPDATE...RGass
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...Behringer
MARINE...Sarment

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