FXUS66 KMTR 170840
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
140 AM PDT Sun May 17 2026

...New KEY MESSAGES, SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 140 AM PDT Sat May 16 2026

 - Breezy to windy conditions, especially across the North, East,
   and South Bay Mountains along with the Santa Cruz Mountains
   through Monday

 - Hazardous beach conditions through Monday

 - Hazardous marine conditions expected through the weekend

 - Elevated fire weather concerns continue through Monday across 
   the interior with low humidities and strong gusts

&&

.SHORT TERM...
Issued at 140 AM PDT Sun May 17 2026 (Today and tonight)

Water vapor imagery shows a broad trough of low pressure over the
West this morning, with one disturbance currently moving across 
Nevada. In response to this system beginning to shift east, 
pressure gradients are starting to relax from their earlier peak. 
At this time, the SFO-ACV is down to -9.5 mbs, while the SFO- LAS 
is down to 12.6 mbs. Even though it is still breezy out there, 
gusts are mostly less than 40 mph along the coast. Therefore, have
canceled the Wind Advisory to better reflect the current
conditions. 

That being said, the winds will still be a concern over the next 
24 to 36 hours though, as another disturbance currently over 
Western Washington and Oregon dives into the Great Basin later 
today and tonight. This disturbances has a more traditional inside
slider trajectory. As a result, expect another round of dry and 
gusty winds to develop. This time though, it will be the offshore
pressure gradients that increase. North to northeast 925 mb and 
the 850 mb winds will increase to 40 kts over the North and East 
Bay after 06z Mon, before spreading south and west through the
night. Therefore, have issued a new Wind Advisory focusing on the
North, East, and South Bay Mountains as well as the Santa Cruz
Mountains for Sunday night through late Monday morning. At this 
point in time, expect the gusts to be in the 45 to 55 mph range, 
with local gusts above 60 mph at the favored locations like Mount 
Diablo. Very dry conditions will accompany these winds, and should
a fire start in dry grass areas, the fuels will carry that fire. 
Therefore, caution is encouraged if you have plans to be working 
outdoors. One less spark. 

&&

.LONG TERM...
Issued at 140 AM PDT Sun May 17 2026 (Monday through Saturday)

As this the broad trough starts to push east on Monday, high 
pressure will start to rebuild over California, and be the dominate 
weather feature through midweek. As a result, a gradual warming
trend will develop, especially across the inland areas. Expect 
some warming at the coast as well, but it will be more moderated,
especially once the marine layer re-estabilishes itself by
Wednesday. Models start to diverge towards the end of the week and
next weekend, with some clusters suggesting another trough forming
off the West Coast, while others suggest a flatter ridge, while 
others suggest the ridge persisting. Therefore, confidences is 
relatively low on what will actually happen. However, believe the
marine layer will likely continue to bring low clouds and fog to
the coastal areas. The question is just how far inland that
influence will go.  Palmer

&&

.AVIATION...
(06Z TAFS)
Issued at 924 PM PDT Sat May 16 2026

Currently VFR at all terminals with the exception of some haze being 
observed at HAF and SNS. High confidence in VFR through the TAF 
period; however, haze will reduce slant range visibilities. Strong 
and gusty onshore winds will relatively diminish overnight before 
veering and strengthening towards the end of the TAF period.

Vicinity of SFO...Currently VFR with gusty westerly flow. High 
confidence in VFR through the TAF period. Strong and gusty westerly 
winds with gusts up to 35 knots are expected through 07Z. Winds will 
veer tomorrow to become northwesterly by the afternoon and 
northerly by late tomorrow night with gusts up to 30 knots expected.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently MVFR with southerly flow at MRY 
and MVFR with gusty southwesterly flow at SNS. Both terminals are 
observing OVC020; however, a look outside the office which is 
located adjacent to MRY shows VFR. The ceilometer is likely 
observing the inversion with lofted sea spray trapped beneath it. 
Aside from that, high confidence in VFR through the TAF period. 
Gusty onshore winds are expected through the TAF period.

&&

.MARINE...
(Tonight through next Friday)
Issued at 924 PM PDT Sat May 16 2026

Widespread hazardous conditions are expected to continue through
the weekend. Near gale force to gale force northerly breezes with
widespread severe gale force gusts are expected through the
weekend. Storm force gusts are expected across the northern outer
waters and along the coastal jet region of Big Sur through
tonight. Rough to very rough seas have built as a result.
Conditions will slowly begin to improve Monday.

&&

.FIRE WEATHER...
Issued at 115 PM PDT Sat May 16 2026

Strong and gusty north to northwest winds continue to build through 
Saturday before becoming north to northeast by Sunday in the higher 
terrain. Expect peak gusts greater than 30 mph for most areas, with 
around 45 to 55 mph along the coast, through gaps and passes, and 
across the ridgelines. Daytime humidity retention will fall to 10-
25% across the interior regions and higher peaks, with limited 
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 early part of 
the week. 

RGass

&&

.BEACHES...
Issued at 140 AM PDT Sat May 16 2026

A Beach Hazards Statement remains in effect for west facing 
beaches along the Pacific Coast 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. 

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday morning for CAZ006-505-
     509-530.

     Wind Advisory from 11 PM this evening to 11 AM PDT Monday for 
     CAZ504-512-514-515.

     Coastal Flood Advisory until 3 AM PDT Tuesday for CAZ506.

PZ...Small Craft Advisory until 3 AM PDT early this morning for SF 
     Bay N of Bay Bridge.

     Gale Warning until 9 PM PDT this evening for Pt Pinos to Pt 
     Piedras Blancas 0-10 nm-SF Bay N of Bay Bridge.

     Gale Warning until 9 PM PDT this evening for Mry Bay-Pigeon Pt 
     to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes 
     to Pigeon Pt 0-10 nm.

     Storm Warning until 3 AM PDT early this morning for Pt Arena to 
     Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

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

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

&&

$$

SHORT TERM...Palmer
LONG TERM....Palmer
AVIATION...Sarment
MARINE...Sarment

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Prepared by Boulder-Creek.com Weather at: Sun May 17 04:30:04 PDT 2026