495
FXUS66 KMTR 032116
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
216 PM PDT Tue Jun 3 2025

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

.SYNOPSIS...
Issued at 205 PM PDT Tue Jun 3 2025

Cloudy coastal mornings followed by breezy and clearing afternoons
will the prevailing pattern over the next few days. Coastal areas
look to peak into the 60s while more interior areas stick to the
80s. The overnights keep lows in the 50s. Expect a slight warming
and drying trend over the weekend and into the next work week.

&&

.SHORT TERM...
(This evening through Wednesday)
Issued at 205 PM PDT Tue Jun 3 2025

The more active weather affecting southern Monterey County has
calmed as the high-based convection subsided and the airmass has
moved into the marine environment.

The complex of eddies flowing due west of San Francisco have pulled
much of the low stratus out to the sea, allowing for earlier
clearing than yesterday and improved coastal warming. This has also
allowed for a break in the local pattern that helped pull some of
that smoke from the Canadian wildfires into the area over the last
few days, causing some improvements in the hazier conditions.


Cloudier conditions and pockets of fog look to make a stronger
comeback tonight, but the oscillations out to sea look to prevent
cloud cover from flowing into the souther SF Bay. So while cloudy
conditions are expected from much of the North Bay, Monterey Bay,
and along the coast, SFO and Oakland as well as the South Bay look
to stay mostly clear.

The afternoon forecast package ran through the potential for coastal
drizzle and mist with a fine-toothed comb, but the pattern seems
more favorable for patches of fog into early Wednesday, especially
in the favored North Bay vallies, coastal Sonoma, and the Northern
Monterey Bay.

Aside from some additional eddy activity off the coast, the region
begins to settle into a more typical early summer pattern for the
mid week. Cloudy coasts and bays in the mornings, with breezy
afternoons, and highs ranging from the 60s on the coast to the 80s
into the interior. Some of the more interior higher elevations,
such as the Gabilan Range, will begin to see improved overnight
humidity recoveries, offering some much needed relief from the dry
days followed by fairly dry night over the last few days.

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 205 PM PDT Tue Jun 3 2025


The upper-level pattern leans toward a weak ridging setup into
the weekend, causing some warming and drying, but nothing extreme.
A few of the interior valleys look to peak in the low 90s, but a
still intact, yet compressed marine layer looks to mitigate mush
additional warming for the more coastal areas. In fact, the
compressing of the marine layer may wring out some coastal drizzle
in the early mornings over the weekend and into the next work
week.


Into the longer term forecast, the upper level pattern goes back to
more of a neutral/zonal flow pattern into the next work week. This
will offer some cooling and get back to that summer in San Franciso
pattern. Deeper into the next work week, models hint at another low
pressure passage which could call for more cooler and windier
conditions, but there is still more polishing that needs to be done
in that portion of the forecast, so keep checking in!

&&

.AVIATION...
(18Z TAFS)
Issued at 1130 AM PDT Tue Jun 3 2025

VFR anticipated by 20 UTC with a low chance for MVFR cigs
lingering after this time. While the potential for VFR at KHAF is
~20%, trends in satellite support a few hours of VFR. Trends will
be monitored. VFR is anticipated through the entire period at KLVK
and KSJC. Largely diurnal breezes are anticipated, with medium
confidence in elevated winds this afternoon along the west Delta
and SF Bay, where winds may gust to around 25 knots at KAPC and
KOAK. Though KOAK tends to `overachieve` with respect to wind
gusts, probabilities 25+ knot gusts are less than 10%.

There may be just enough influence from a diffuse trough sliding
through the Great Basin to mitigate what would otherwise be a much
more prolonged poor ceiling/visibility event at TAFs on Wednesday
AM. The exception is at KHAF. Local effects at KSTS may still
dominate aviation weather conditions through at least sunrise. As
winds aloft become more northerly in response to the
aforementioned trough, MVFR ceilings/visibility will erode/lift
with VFR anticipated through the remainder of the TAF set. Because
the trough is very subtle in the guidance, there`s low to medium
confidence in the forecast. The current TAF set remains very
optimistic compared to some of the traditional guidance and if the
trough has less in the way of influence, noteworthy alterations
to the forecast will be needed. Otherwise, reductions in slant
visibility due to HZ are anticipated, however, impacts to
horizontal/runway visibility is expected to be limited.

Vicinity of SFO...VFR for a majority of the TAF set. Confidence
in MVFR stratus is low and guidance advertises a 20-30% chance for
cigs around FL015. If an upper trough to the north and east of
the region has less in the way of influence, then there will be an
opportunity for a longer duration ceiling event at SFO on
Wednesday morning. For now, a 2-4 hour window of ceilings around
FL015 has been advertised, though if winds aloft become northerly,
it`s possible that VFR prevails through the entire TAF cycle.
Otherwise, diurnal NW to WNW breezes are anticipated, with an
increase in the gust potential (around 25 knots) near/after 21 UTC
as winds funnel through the San Bruno Gap.

SFO Bridge Approach...HZ may result in slant visibility
reductions and despite the lack of cigs, occasional loss of VAPS
may result if HZ is sufficiently thick/dense.

Monterey Bay Terminals...VFR will prevail through late
afternoon/early evening, with an increased potential for MVFR/IFR
ceilings, especially by 06 UTC. The wind patterns are a little
atypical and this lowers confidence in the exact onset/timing of
ceilings at KMRY and KSNS. The model consensus and time of year,
however, does support a more prolonged periods of reduced
ceilings, especially at KMRY. The current KSNS TAF may be a little
too pessimistic on the back end of stratus and it`s conceivable
that VFR returns prior to 17 UTC Wednesday if a Monterey Bay eddy
develops and disrupts stratus intrusion into the Salinas Valley.

&&

.MARINE...
(Tonight through next Sunday)
Issued at 205 PM PDT Tue Jun 3 2025

Strong high pressure to the north and low pressure inland will
support near gale force wind gusts. The most likely areas for gale
force winds and hazardous seas will be over the outer waters
north of Point Reyes with strong gale force gusts. South of
Pigeon Point winds will be weaker and westerly to southerly. The
Delta breeze will also increase later this afternoon, resulting
in hazardous boating conditions for portions of the San Pablo Bay
and west Delta regions. Southerly coastal jets are forecast to
develop along the Pacific Coast near the Monterey Peninsula and
also along the Santa Cruz coastline. This may result in pockets of
rougher seas and stronger winds.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for SF Bay N of
     Bay Bridge.

     Gale Warning until 9 PM PDT Wednesday for Pt Arena to Pt Reyes
     10-60 NM.

&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...Bain
MARINE...Bain

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