FXUS66 KMTR 180648
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1148 PM PDT Sun May 17 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 1147 PM PDT Sun May 17 2026

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

 - Hazardous beach conditions through Monday

 - Hazardous marine conditions expected through Monday

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

&&

.SHORT TERM...
Issued at 1147 PM PDT Sun May 17 2026
(Tonight through Monday)

An upper level low pressure system digs into the tri-state area of 
CO, UT, and WY by late Monday morning. We remain under the influence 
of the broader trough associated with it, leading to breezy offshore 
flow. North to northeast winds pick up tonight across the Santa Cruz 
Mountains, the interior North Bay Mountains, and the Eastern Santa 
Clara and East Bay Hills. Sustained wind speeds of 15 to 30 mph 
along with gusts up to 50 mph, though localized gusts up to 60 mph 
are expected for favored ridges, gaps, and passes. These winds will 
usher in drier air to the region as well, keeping the fire weather 
threat elevated for interior Bay Area and Central Coast locations. 
In terms of more every day hazards from the winds, impacts include, 
but are not limited to difficult driving, especially for high profile 
vehicles, downed tree limbs, the potential for power outages, and 
the possibility of loose or unsecured items being blown around. 

Winds begin to ease late Monday morning into the afternoon and will 
continue to decrease into the evening and overnight hours. Offshore 
winds should bring some warmer temperatures to the region, the 90s 
for the interior Bay Area valleys, the 60s to low 70s along the 
coast, and the mid 70s to low 80s for the Central Coast Valleys. 


&&

.LONG TERM...
Issued at 1147 PM PDT Sun May 17 2026
(Tuesday through next Sunday)

Upper level troughing looks to hold just west of the Desert 
Southwest and into southern CA Tuesday into Wednesday, leaving us 
with teetering between quasi-zonal and barely trough-y. Weak 
offshore lingers at least over the interior mountain ranges through 
Tuesday into Wednesday, with onshore flow trying to make a diurnally 
driven push each afternoon/evening. During this time high pressure 
just to the west of us (over the eastern Pacific) builds, pushing 
towards the coast mid week. The upper level trough begins to meander 
south to southwest of southern California late week. This should 
bring a return of onshore flow to the region and perhaps the marine 
layer. Current guidance suggests we could see a 500ft marine layer 
return by Wednesday, with a 1000-1200ft marine layer by Thursday and 
Friday. Will need to keep an eye on this as it will affect how 
temperatures pan out.

&&

.AVIATION...
(06Z TAFS)
Issued at 936 PM PDT Sun May 17 2026

Currently VFR at all terminals with the exception of haze being 
observed at HAF. High confidence in VFR through the TAF period; 
however, haze will reduce slant range visibilities. Strong and gusty 
northerly/offshore winds will prevail tonight with onshore flow 
returning tomorrow afternoon. Low level wind shear (LLWS) is 
expected through tomorrow morning. The 18Z end time is pessimistic 
with most LLWS activity expected to occur when the atmosphere is 
decoupled overnight until it recouples tomorrow morning, probably 
closer to 15Z. LLWS is primarily expected between FL015 and FL020 
with speeds of 35-45 knots out of the north/northeast.

Vicinity of SFO...Currently VFR with gusty northerly flow. High 
confidence in VFR through the TAF period. Strong and gusty northerly 
winds are expected through the morning before backing to 
become onshore tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with southerly flow at MRY 
and VFR with northwesterly flow at SNS. High confidence in VFR 
through the TAF period. Diurnal winds are expected through the TAF 
period.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 936 PM PDT Sun May 17 2026

Hazardous conditions are expected tonight before improving
tomorrow. Strong northerly breezes with widespread gale force
gusts and rough to very rough seas are expected tonight.
Conditions will slowly begin to improve tomorrow as winds diminish
and seas abate. Conditions will remain hazardous to small craft
throughout the week, especially for the northern outer waters.

&&

.FIRE WEATHER...
Issued at 443 AM PDT Sun May 17 2026

Strong and gusty north to northwest winds continue to affect the 
region, shifting slightly into Sunday afternoon, and becoming 
north to northeast. Expect peak gusts greater than 30 mph for most
areas, with around 45 to 55 mph along through gaps and passes, 
and across higher terrain. Daytime humidity retentions loos to 
stay around 10- 25% across the interior regions and higher peaks, 
with limited overnight humidity recoveries. Strong winds persist 
into the early Monday before diminishing. Humidities will be slow 
to recover into the work week as a light offshore flow will 
continue to affect the district.

&&

.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 until 9 AM PDT Monday for CAZ006-505-509-
     530.

     Wind Advisory until 11 AM PDT Monday for CAZ504-512-514-515.

     Coastal Flood Advisory until 3 AM PDT Tuesday for CAZ506.

PZ...Gale Warning until 3 AM PDT Monday 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 Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to 
     Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.

     Small Craft Advisory until 9 PM PDT Monday for Mry Bay.

     Gale Warning until 9 AM PDT Monday for Pt Arena to Pt Reyes 10-
     60 NM.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Sarment
MARINE...Sarment

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Prepared by Boulder-Creek.com Weather at: Mon May 18 00:30:03 PDT 2026