FXUS66 KMTR 270459
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
959 PM PDT Tue May 26 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 1242 PM PDT Tue May 26 2026
- Strong northerly winds will bring widespread hazardous marine
and beach conditions through Wednesday morning
- Cooler, unsettled weather conditions remain possible through
Thursday
- Warming and drying trend Friday and beyond
&&
.UPDATE...
Issued at 916 PM PDT Tue May 26 2026
Showers and isolated thunderstorms that moved through Napa and
Contra County this afternoon and early evening have come to an end
with some locations like Brentwood receiving 0.40" and some
higher spots in Napa County getting around 0.25". Otherwise we'll
continue to remain on the backside of the upper level low that
will primarily stall through tonight and tomorrow. We will see a
notable easing in winds through the remainder of tonight into
Wednesday along the coast and the interior.
&&
.SHORT TERM...
Issued at 1242 PM PDT Tue May 26 2026
(This evening through Wednesday)
Cool conditions are forecast to prevail today in wake of the early
morning frontal passage. Temperatures this afternoon are forecast to
be in the middle-to-upper 50s to middle 60s near the coast with
middle 60s to lower 70s across the interior with amble amount of
sunshine. Speak of sunshine, there is also a chance of rain showers
over Napa County through this evening as the forecast calls for
generally 150-250 J/kg of most unstable CAPE. Some of these rain
showers (if they develop) may move across the interior East Bay this
evening before the loss of daytime heating reduces the instability
aloft. It will also remain breezy through the evening and into
tonight, especially near the coast and in the higher terrain
across the Bay Area and Central Coast. Onshore winds will continue
with gusts of 30-40 mph with isolated gusts up to 50 mph across
the North Bay Interior Mountains and East Bay Hills.
As the cut-off low pressure lingers over northern (today) and
central (tomorrow through Thursday), we are forecasting unsettled
weather conditions to prevail. However, wind speeds are forecast to
diminish slightly. With similar conditions expected on Wednesday, the
greatest potential to see more than 0.10" (15-25% probability) will
be across the interior Bay Area and Monterey/San Benito County.
There is also a chance of thunderstorms, yet they largely remain
less than 15%.
&&
.LONG TERM...
Issued at 1242 PM PDT Tue May 26 2026
(Wednesday night through next Monday)
On Thursday, there is a greater potential for rain showers across
the region with the mid/upper level cut-off low forecast to be just
off of the Bay Area/Central Coast coastline. Thus, PWAT values are
forecast to be around 1.00". However, the thunderstorm potential
will be less as the atmosphere becomes more stable. The NBM
probabilities of seeing greater than 0.25" remain around 10-25% from
11 PM Wednesday night - 11 PM Thursday morning. That said, the
probabilities from the convective-allowing ensemble guidance is
greater than 50% of reaching or exceeding 0.25" across places
outside of the North Bay. All that said, looking like a wide range
of possibilities with varying outcomes as far as rainfall amounts
go, yet widespread flooding concerns remains very low. Just expect
wet roadways across the region during periods of rainfall.
The low pressure system responsible for the unsettled weather early
this week will finally shift eastward with a shortwave ridge
building in to the Bay Area/Central Coast. However, more zonal flow
will bring a slight warming and drying trend to the region and is
forecast to prevail into early next week.
&&
.AVIATION...
(06Z TAFS)
Issued at 959 PM PDT Tue May 26 2026
Primarily VFR conditions tonight outside of coastal areas. Guidance
suggests some potential for MVFR CIGs to impact interior Bay Area
airports tonight but confidence is on the lower end. High resolution
guidance shows RH values around 80-90% in the lower levels of the
atmosphere. This supports at least few to scattered low level clouds
but not confident on BKN/OVC conditions. LAMP guidance shows a low
chance for MVFR CIGs and leans towards keeping into sites VFR
overnight. Winds are easing across the region but will remain
locally gusty overnight. The SFO-WMC gradient will be weaker on
Wednesday than it was on Tuesday but it will still be around -10 to -
12 mb at its afternoon peak. This supports another round of gusty
winds tomorrow although gusts peak around 20-25 knots instead of 30-
35 knots today. Widespread showers return towards the end of this
TAF period and continue into the rest of tomorrow night.
Vicinity of SFO...VFR through the TAF period. Not anticipating low
clouds to develop at SFO tonight with CIGs staying above 3000 ft.
Gusty westerly winds will diminish overnight before another round of
breezy winds tomorrow afternoon/evening. Tomorrow's winds will be
weaker with gusts peaking around 25 knots. Scattered showers
approach SFO after 06Z tomorrow with shower chances increasing
further around 12Z.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR CIGs continue through 17/19Z with VFR
the rest of the day. Westerly winds are diminishing at MRY and SNS
with winds to ease further overnight. Winds restrengthen during the
afternoon/evening when gusts to around 20 knots are expected.
Scattered showers are possible in the vicinity of MRY tonight with
shower chances becoming more widespread (impacting both MRY and SNS)
tomorrow night.
&&
.MARINE...
(Tonight through next Monday)
Issued at 916 PM PDT Tue May 26 2026
Fresh to strong northwest winds continue tonight with winds
gradually diminishing across the inner waters heading into
tomorrow. Occasional near gale to gale force gusts are possible
across the far outer waters through Wednesday afternoon. Rough
seas continue with wave heights between 12 to 16 feet through
Thursday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 9 AM PDT Wednesday for CAZ006-505-
509-529-530.
PZ...Small Craft Advisory until 3 AM PDT Wednesday for Mry Bay-Pigeon
Pt to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay
N of Bay Bridge.
Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt
Reyes 0-10 nm.
Gale Warning until 3 AM PDT Wednesday for Pt Pinos to Pt Piedras
Blancas 0-10 nm.
Small Craft Advisory until 3 PM PDT Thursday for Pt Arena to Pt
Reyes 10-60 NM.
Small Craft Advisory until 9 PM PDT Wednesday for Pigeon Pt to
Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Kennedy
MARINE...Kennedy
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Prepared by Boulder-Creek.com Weather at: Tue May 26 22:30:02 PDT 2026
From the National Weather Service
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