359
FXUS66 KMTR 150342
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
842 PM PDT Wed May 14 2025

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 1229 PM PDT Wed May 14 2025

Gradual warming trend into Friday before a slight cooldown over the
weekend. Gusty winds will develop late Friday into Sunday. Warming
trend resumes early next week.

&&

.UPDATE...
Issued at 842 PM PDT Wed May 14 2025

After a few active evenings weather wise, tonight is a tad more
mellow with lighter winds and a few high clouds passing overhead.
Why the change? High pressure nosing in from the west and
northwest is leading this change in the sensible weather.
Temperatures along the coast were similar to the last few days,
but once you moved away from any marine influence temperatures
climbed into the 70s and near 80 degrees. While these temperatures
are still below seasonable averages they were still 5 to 10
degrees warmer than Tuesday.

For the rest of tonight - a marine layer will form again, but it
won`t be like a June Gloom marine layer covering the coast and
inland valleys. Coverage for Thursday morning will likely be
patchy along the coast and locally inland.

As noted below pretty quiet weather through the short term.

Here a few weather impacts will be focusing on the next seven days
and beyond

--Subtle warming trend to finish the work week
--Much stronger northerly winds kicks in for the weekend. Wind
 advisories may be needed Saturday into Sunday with the strongest
 winds over the coastal waters, coastal areas, and higher peaks.
--burst of northerly/offshore flow Sunday night in Monday
--Solid warm up the middle of next week with far interior
 locations hitting moderate HeatRisk
--8 to 14 CPC shows a warming and drying trend
--CPC highlights portions of CA with a slight and moderate risk
 for Excessive Heat May 22 through May 28

MM

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 1229 PM PDT Wed May 14 2025

An upper level ridge over the eastern Pacific extends itself over
the West Coast, resulting in benign weather for the next couple of
days. Satellite imagery shows thin high clouds entering the North
Bay, lingering stratus at the immediate coast of the San Mateo
Peninsula, and fair weather cumulus popping up in the eastern Santa
Clara Hills and the mountains of interior Monterey and San Benito
Counties. Overall conditions remain dry and seasonably warm
throughout the region with highs ranging from the lower to middle
70s inland and the middle 60s to lower 70s along the Bayshore, while
onshore flow keeps the coastal regions cool with highs in the upper
50s to lower 60s. Inland temperatures warm slightly tomorrow with
the interior valleys reaching the middle 70s to the lower 80s, but
otherwise the forecast is similar to today`s weather with coastal
stratus south of the Golden Gate that moves down the Salinas Valley
and into the Morgan Hill-Hollister area.

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 1229 PM PDT Wed May 14 2025

Seasonably warm conditions continue on Friday with the inland
valleys remaining near the middle 70s to lower 80s, while the
Bayshore sees highs in the upper 60s to middle 70s. Highs along the
coastal regions remain relatively constant and cool, owing to the
sea breeze influence.

Later on Friday through Saturday, an upper level trough will develop
off the Pacific Northwest and deepen into a cutoff low in the Great
Basin, causing a dip in temperatures for the upcoming weekend.
Saturday`s high temperatures will dip by around 10 degrees in the
interior valleys, to around the middle 60s to lower 70s, while the
Bayshore drops into the lower to middle 60s. Although the cutoff low
will continue to move eastwards, leaving a classic "inside slider"
scenario less likely, the pressure gradient between the cutoff low
and a ridge in the eastern Pacific will still result in gusty winds
across the region later on Friday into Sunday. The current forecast
continues to show wind gusts reaching 25 to 30 mph across the region
with gusts up to 45 mph possible at the ridgelines, along the coast,
and through favored gaps and passes.

Warming temperature will return for the early part of next week with
high temperatures rising to the lower 80s to lower 90s inland, or
around 5 to 10 degrees above seasonal averages. On the backside of
the cutoff low, northerly winds could develop in the interior
regions, especially in Napa County and the interior East Bay,
helping to reinforce the warmer and drier conditions in those areas.

&&

.AVIATION...
(00Z TAFS)
Issued at 455 PM PDT Wed May 14 2025

Satellite shows patchy stratus developing along the Monterey Bay
Shoreline and high level clouds building in over the Bay Area. The
marine layer is expected to compress overnight which will help to
limit stratus to coastal airports and along the Bay Shoreline
tonight. MVFR-IFR CIGs will filter in to HAF, MRY, SNS, and OAK
overnight with highest confidence in IFR CIGs at HAF and MRY.
Elsewhere, patchy low level clouds may develop but confidence is low
that a BKN/OVC layer will develop. Low confidence that fog/stratus
will reach STS and APC overnight but probabilistic guidance
indicates some potential for lowered VIS/CIGs to develop between 12Z-
16Z tomorrow morning. Onshore winds will ease and shift offshore
through the overnight hours before moderate onshore winds, between
10-15 knots for most sites, returns during the day tomorrow.

Vicinity of SFO...CIGs look to stay VFR through the TAF period but
NBM guidance suggests a period of MVFR CIGs are possible in the 09Z-
18Z timeframe. High resolution HRRR guidance keeps stratus on the
eastern side of the bay (reaching OAK) but does not show it filling
in over the SF Bay. Currently leaning more towards HRRR guidance
with low confidence that CIGs will fill in over the SF Bay tonight.
Breezy northwest winds will ease overnight before strengthening
again tomorrow afternoon through the end of the TAF period.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus is building in along the Monterey
Bay coastline so bumped up stratus arrival at MRY by an hour. Low to
moderate confidence that stratus will reach MRY prior to 02Z due to
the offshore stratus bank starting to intrude inland. CIGs generally
remain MVFR at SNS tonight but will drop into the IFR category at
MRY late tonight through early tomorrow morning. CIGs look to
improve mid to late morning with VFR conditions expected through the
end of the TAF period. Moderate onshore winds will ease overnight
before moderate northwest winds (10-15 kt) return tomorrow afternoon.

&&

.MARINE...
(Today through Monday)
Issued at 835 PM PDT Wed May 14 2025

Strong, gale force northwesterly winds continue across the outer
coastal waters while fresh to strong northwesterly winds continue
across the inner coastal waters. Moderate seas bringing steep, fresh
swell will continue through Saturday with significant wave heights
between 10 to 12 feet expected across the outer waters. Sunday into
next week, gale force to near gale force winds will become more
widespread over the coastal waters and seas will become rough.
Hazardous conditions will continue through the end of the forecast
period.

&&

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

     Small Craft Advisory from 3 PM to 9 PM PDT Thursday for Mry Bay.

     Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 0-
     10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt
     Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory from 3 PM Thursday to 3 AM PDT Friday for
     Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

     Gale Warning until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 10-
     60 NM-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Kennedy
MARINE...Kennedy

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
X.com/nwsbayarea
www.youtube.com/nwsbayarea