072
FXUS66 KMTR 281621
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
921 AM PDT Sat Jun 28 2025

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 257 AM PDT Sat Jun 28 2025

June Gloom continues with cloudy coastal conditions, sunny
afternoons, and returning cloud cover each evening. Temperatures
cool through the weekend as the marine layer deepens and reaches
farther inland. The day to day patterns hold fairly steady for the
next week.

&&

.UPDATE...
Issued at 920 AM PDT Sat Jun 28 2025

The Fort Ord Profiler shows the marine layer at a depth of about
1200-1500 ft with stratus blanketing the coastline. Skies remain
clear across the interior today while coastal regions remain
overcast to partly cloudy for much of the day. Weak upper level
troughing continues to develop over the Western US which will allow
the marine layer to deepen to around 2000 ft tonight. As a result,
overcast conditions will be much more widespread tonight/tomorrow
morning than they are today. Otherwise, the June Gloom pattern
continues for much of the next week as persistent troughing
lingers over the Western US.

&&

.SHORT TERM...
(Today and tonight)
Issued at 257 AM PDT Sat Jun 28 2025

This morning has a very similar coastal stratus pattern compared to
last night. The key difference is the slightly more compressed
marine layer offering lower level cloud cover and better chances of
coastal drizzle and fog. The feed of marine clouds to the immediate
coast looks to persist for most of the day with maybe a few passing
moments of clearing. Areas slightly inland will some late morning
clearing, with breezy conditions especially along the very edge of
cloud cover to the clearing areas. These are also the areas that are
the hardest to pin down the high temperatures for this afternoon as
the sooner a spot clears, the warmer it gets, but the next town over
may not clear at all. But this is just how the June Gloom pattern
works and this pattern holds strong for much of the forecast.

For the areas in the clouds today, expect highs to peak in the upper
50s and low 60s with drizzle and pockets of fog to both start and
end the day. Areas that see some clearing will be breezier and peak
around 70 degrees. Farther inland is where we begin to see the 80s
and 90s with the upper 90s to around 100 in the farthest of the far
interior.

Cloud cover will be quicker to move inland tonight. The deepening
and expansion of the marine layer will allow that cloud cover to
filter into the slightly more interior valleys and provide fairly
widespread coverage into the late night.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 257 AM PDT Sat Jun 28 2025

A weak trough and low pressure is building into the region which will
continue to deepen the marine layer and allow it to expand farther
inland. This trough and low combo will be very slow to move through
the region, and now the longer term models hint at further troughing
in its wake.

This will kick off a slight cooling trend for the more interior
areas in the early work week with that increasing marine influence
and onshore flow. Areas along the coast will see stable temperatures
as the cloud cover becomes very persistent. The slightly more inland
areas will see more pronounced cooling as the cloud cover begins to
last longer into the mornings and even into the afternoons. It will
be the matter of a few miles between a cloudy day with highs in the
60s and a sunny day with highs in the 70s and 80s. Very typical for
June Gloom!

And this is what our pattern looks like for much of the forecast
after the cooling plateaus in the early work week: Cloudy and foggy
mornings and early afternoons, breezy in the areas that see clearing
skies, warm and dry in the areas that stay clear, and repeat.

The very long term forecast shows zonal flow becomes favorable after
the troughing patterns exit. This hints as slight reductions in
marine influence, but not by much.

&&

.AVIATION...
(12Z TAFS)
Issued at 414 AM PDT Sat Jun 28 2025

VFR is expected to persist for the Bay Area terminals until late
tonight/early Sunday morning when stratus encroaches farther
inland than the previous couple of nights. Farther south for the
coastal terminals on Monterey Bay, IFR will persist through the
morning with some clearing likely this afternoon, with stratus
returning early this evening. Lower confidence for stratus
reaching North Bay sites with dry air persisting just above the
marine layer.

Vicinity of SFO...VFR is expected to prevail until late tonight
when stratus returns with a steady fetch of onshore flow.
Confidence is higher for the return of stratus tonight than
previous couple of nights. Surface winds may become N/NE for a
short time late this morning/early afternoon as a weak surface
low develops over the Bay Area, with onshore flow returning by
late afternoon.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals...IFR is expected to persist through the
morning under a compressed marine layer. Dry air just above the
marine layer will mix out the stratus for the afternoon with
IFR/LIFR cigs returning in the early evening hours.

&&

.MARINE...
(Today through Thursday)
Issued at 920 AM PDT Sat Jun 28 2025

Fresh to strong northwesterly breezes will continue over the
outer waters north of Point Reyes through Sunday, with southerly
winds developing along the coast south of Point Reyes today.
Moderate to rough seas continue through late this morning, with
significant wave heights gradually subsiding later tonight into
Sunday as winds ease. The next round of elevated wave heights,
strong northwesterly breezes, and moderate to rough seas begins
Tuesday and continues through late next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...JM
MARINE...Canepa

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