FXUS66 KMTR 151932
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1232 PM PDT Fri May 15 2026
...New SHORT TERM, LONG TERM, BEACHES...
.KEY MESSAGES...
Updated at 1229 PM PDT Fri May 15 2026
- Breezy and gusty winds this afternoon into the weekend
- Hazardous marine conditions expected this afternoon into the
weekend
- Elevated fire weather conditions continue through Monday across
the interior with low humidities and strong gusts
- Blustery winds for all beaches into the weekend and hazardous
beach conditions for west facing beaches this afternoon through
Monday morning
&&
.SHORT TERM...
Issued at 1229 PM PDT Fri May 15 2026
(This evening through Monday)
Skies are generally clear across the Bay Area and Central Coast as
the fringes of an upper level ridge continue to impact the region.
Any stratus formation tonight should be limited in extent, possibly
confined to favored valley or mountaintop locations. High
temperatures today range from the upper 70s to the upper 80s
inland, the upper 60s to upper 70s along the bays and the upper
50s to middle 60s along the Pacific coast. Highs through the
weekend will dip into the 70s to the lower 80s inland, and the
upper 60s to middle 70s near the Bays.
The upper level pattern features a trough axis moving parallel to
the coast of British Columbia and a ridge stalled out over the
eastern Pacific. As that trough axis moves into the Pacific
Northwest through the day, the pressure gradient should increase and
lead to a strengthening of the wind gusts across the region. Wind
gusts will reach 35 to 45 mph today along the coast, through gaps
and passes, and across the ridgelines today, while gusts of 20 to 30
miles per hour are expected to develop elsewhere. Notably, unlike
the traditional diurnal wind patterns, winds will not diminish
overnight across the coast and at the higher elevations. Indeed, at
the higher elevations, the strongest winds may occur during the
nighttime as a decoupled atmosphere exposes these areas to strong
jets aloft.
Saturday and Sunday look to be the peak of this wind event as the
upper level trough continues to crawl into the northern Rockies
through Sunday, further tightening the pressure gradient across the
state, before dropping into the Great Basin on Sunday and setting
off the inside slider pattern. This is also the time that a strong
jet develops at and just off the coast south of Cape Mendocino and
especially to the south of Point Arena. Wind gusts along the coastal
regions inch up to around the 40 to 45 mph (locally up to 50 mph)
range, with gusts around 35 to 45 mph through the San Bruno gap and
the northern Salinas Valley, and 25 to 35 mph elsewhere. Winds will
peak Sunday night into Monday morning for the interior mountains of
the North and East Bay down into parts of the Santa Cruz Mountains,
as a jet of downsloping air comes down from the Klamath Mountains
and the northern Sierra Nevada and through the Sacramento Valley.
Gusts of 40 to 45 mph, locally up to 50 mph, are expected along the
ridgelines.
With the potential mixing down of the intense winds aloft down to
the surface I've considered issuing a Wind Advisory for the
immediate coast on Saturday. The latest guidance from the NAM
suggests a couple of timeframes, one on Saturday morning and another
Saturday evening into the overnight period, when 925 mb winds (that
is, winds around 2,500 ft above sea level) reach 40 to 55 knots
across the coastal regions. Should these winds mix down to the
surface, the coastal regions will reach Wind Advisory criteria
easily. The main source of uncertainty then is whether the winds
will mix down to the surface, and high resolution models are showing
some signs that it's possible at favored coastal locations -- think
Point Reyes, or Pillar Point near Half Moon Bay. What we haven't
seen is those wind gusts over a wide enough area to warrant a Wind
Advisory across the coastal zones. The night shift will re-evaluate
the situation and may issue a Wind Advisory if warranted.
Wind Advisory or not, the strong gusts will still result in
significant impacts to those impacted by them, including loose
branches, isolated downed trees resulting in potential power
outages, blowing sand across beaches, and difficult driving
conditions for high profile vehicles. Now is the time to bring in
loose items outdoors, while the winds are still relatively calm. In
addition, the strong northwest to north winds will result in large
and turbulent waves across the beaches, and dry to very dry
conditions in the interior which will elevate the fire weather
danger through Monday. Sunday and Monday looks to be the driest days
as the daytime relative humidities reach 10 to 25% across the
interior and within the higher elevations of the coastal ranges. See
the BEACHES and FIRE WEATHER sections for more details on these
threats.
&&
.LONG TERM...
Issued at 1229 PM PDT Fri May 15 2026
(Monday night through next Thursday)
By Monday afternoon, the upper level low will weaken and pull away
into the northern Rockies, allowing the pressure gradient to slacken
and a developing upper level ridge over the eastern Pacific to begin
influencing the weather pattern. With California sitting between the
building ridge and the lingering trough, high temperatures across
the region are still a little uncertain. Continuing to see the
NBM output run a little warm for the next work week, so after
collaboration with our neighbors and national centers, the high
temperature forecast was tamped down by as much as 3 to 5 degrees,
especially along the coastal and valley regions. The general
pattern will be for highs in the 80s to the lower 90s inland, the
middle 70s to the middle 80s near the bays, and the 60s to lower
70s along the Pacific coast.
&&
.AVIATION...
(18Z TAFS)
Issued at 1025 AM PDT Fri May 15 2026
Currently VFR at all terminals with the exception of some mist and
haze being observed at HAF and SNS respectively. High confidence in
VFR through the TAF period; however, haze will reduce slant range
visibilities. Winds will strengthen through the morning, becoming
strong and gusty this afternoon and evening with widespread gusts of
25 to 35 knots expected.
Vicinity of SFO...Currently VFR with northwesterly flow. High
confidence in VFR through the TAF period. Winds will continue to
back and strengthen through the morning, becoming strong and gusty
this afternoon. Gusts up to 30 knots are likely this afternoon and
evening with isolated gusts up to 35 knots possible.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Currently VFR with northwesterly flow at
MRY and MVFR with westerly flow and haze at SNS. Aside from haze,
high confidence in VFR through the TAF period. Onshore winds will
continue to strengthen through the morning, becoming moderate and
gusty this afternoon and evening.
&&
.MARINE...
(Today through Wednesday)
Issued at 1025 AM PDT Fri May 15 2026
Widespread hazardous marine conditions are expected today and
through the weekend. Strong to near gale force northerly breezes
will increase through the weekend to become near gale force to
gale force with widespread severe gale force gusts. Isolated
storm force gusts are expected along the coastal jet region of
Big Sur. Rough to very rough seas will build as a result.
Conditions will slowly begin to improve Monday.
&&
.FIRE WEATHER...
Issued at 511 AM PDT Fri May 15 2026
Gusty offshore winds are building and strengthen through the
weekend, leading to elevated fire concerns. Peak gusts above 30 mph
for most areas are expected, with around 40 to 50 mph along the
coast, through gaps and passes, and across the ridgelines. Very low
daytime humidities of 15-25% will prevail across the interior
regions and higher peaks, with reduced overnight humidity
recoveries. Strong winds persist into the early part of Monday
before diminishing, but humidities will be slow to recover as a
modest offshore flow continues into the work week.
&&
.BEACHES...
Issued at 1229 PM PDT Fri May 15 2026
A Beach Hazards Statement will go into effect for west facing
beaches along the Pacific Coast from 3 PM today through 9 AM
Monday due to strong winds over the marine environment leading to
hazardously strong wind waves and overall rough seas. Dangerous
swimming, boating, and surfing conditions can be expected. Large
breaking waves can overpower swimmers resulting in significant
physical injury and increase the risk of drowning. Gusts will stay
strong along the immediate coast, causing blowing and drifting
sand and increased sea spray. Water rescue attempts may be
hampered by reduced visibilities from the sea spray. Remember,
NEVER turn your back on the ocean.
RGass/DialH
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday morning for CAZ006-505-
509-530.
Coastal Flood Advisory from 10 PM Saturday to 3 AM PDT Tuesday
for CAZ506.
PZ...Small Craft Advisory until 3 AM PDT Sunday for SF Bay N of Bay
Bridge.
Small Craft Advisory until 3 PM PDT this afternoon for Mry Bay.
Gale Warning until 9 PM PDT Sunday for Mry Bay.
Gale Warning until 9 PM PDT Sunday for Pigeon Pt to Pt Pinos 0-
10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-
10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-
10 nm.
Gale Warning until 9 AM PDT Saturday for Pt Pinos to Pt Piedras
Blancas 0-10 nm.
Storm Watch from Saturday morning through Sunday evening for Pt
Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Sarment
MARINE...Sarment
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Prepared by Boulder-Creek.com Weather at: Fri May 15 14:30:03 PDT 2026
From the National Weather Service
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