FXUS66 KMTR 170746
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1246 AM PDT Wed Jun 17 2026

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

.KEY MESSAGES...
Updated at 1245 AM PDT Wed Jun 17 2026 

 - Minor coastal flooding due to higher than normal high tides
   anticipated across low-lying coastal areas.

 - Hazardous beach conditions through early Thursday morning with
   increased risk of sneaker waves and strong rip currents.

 - Minor HeatRisk through the end of the week with temperatures
   cooling to below normal.

&&

.SHORT TERM...
Issued at 1245 AM PDT Wed Jun 17 2026 
(Today and tonight)

A marine layer 1000-1500 feet deep will bring extensive cloud
cover to the coast and adjacent valleys this morning. Patchy
drizzle has been observed along the coast and will continue 
through the morning, especially over the higher terrain. By the 
afternoon, clouds should retreat back to the coastline with mostly
sunny skies. The marine influence combined with breezy onshore 
winds this afternoon will keep areas near the coast relatively 
cool, with highs mainly in the 60s to lower 70s. Overall, 
conditions will be very similar to Tuesday. Marine stratus will 
return tonight, along with patchy drizzle redeveloping along the 
coast.

High pressure over the area will start to weaken today, which 
will bring about 2-5 degrees of cooling inland. This will place
temperatures near normal for mid June with highs in the upper 70s
to lower 90s. Most areas will see Minor HeatRisk today with only 
isolated pockets in the interior of Moderate HeatRisk. Despite the
slight cooling, continue to practice smart heat safety 
(especially for those more sensitive to the heat) by limiting time
outdoors, taking frequent breaks in the shade (if outdoors), and 
staying hydrated.

Tidal flooding continues across low-lying coastal and Bayshore areas 
through Thursday morning as high astronomical tides combine with 
surge effects from wind, swell, and thermal expansion to bring us 
the highest tides of the summer season. High tides are expected to 
be 1.7 ft above normal (7.5 ft MLLW) at 12:56 AM early this
morning, and 1.2 ft above normal (7.1 ft MLLW) at 1:51 AM on 
Thursday. In addition, the long-period southerly swell continues, 
which increases the risk for sneaker waves and strong rip 
currents, with a Beach Hazards Statement out through Thursday 
morning. See the BEACHES section for more information, but the 
main takeaway is to never turn your back to the ocean!

&&

.LONG TERM...
Issued at 1245 AM PDT Wed Jun 17 2026 
(Thursday through Tuesday)

A trough off the coast will approach the area on Thursday and
further weaken the ridge. This will continue the cooling trend
across inland areas, with highs dropping by around 5 degrees. The
trough will begin to move onshore on Friday. Shower and 
thunderstorm potential associated with the trough will stay 
primarily over the higher terrain to the north and east of the 
area as a deep marine layer greatly inhibits any thunderstorm 
potential. However, there will be enough elevated instability for 
a 5% chance of thunderstorms across far northern Napa and Sonoma 
counties Thursday night and Friday with lower chances to the 
south.

The trough will help to deepen the marine layer Friday into the 
weekend with breezy onshore afternoon/evening winds. The inland 
cooling trend will continue with highs Friday and Saturday only 
reaching the 70s to low 80s at the warmest locations, or about 5 
to 15 degrees below normal. Coastal areas will remain relatively
cool due to the marine influence. Drizzle may also develop over 
the coastal waters and along the coast. Troughing will weaken by 
Sunday with ensembles in agreement that a ridge will rebuild 
across the West early next week. This will bring a warming trend, 
especially inland.

&&

.AVIATION...
(06Z TAFS)
Issued at 958 PM PDT Tue Jun 16 2026

MVFR-IFR stratus is expanding across the region and will impact most 
of the terminals tonight as breezy onshore winds continue to 
diminish overnight. Moderate to high confidence that LVK will remain 
VFR through the night, with some high resolution model output 
showing stratus impacts in the vicinity of the terminal. Stratus 
retreats back to the coast Wednesday morning, with the breezy 
onshore winds resuming in the afternoon, again with a southerly 
component as a mesoscale low develops off the North Bay coastline. 
At HAF, high confidence that ceilings continue through the TAF 
period. Stratus will begin to expand inland again by the end of the 
24-hour TAF period.

Vicinity of SFO... VFR conditions at present with breezy west-
northwest winds diminishing through the early overnight hours. 
Moderate confidence in MVFR-IFR stratus timing at SFO, but ceilings 
are expected to develop by 10Z. Stratus will dissipate through 
Wednesday morning with breezy west winds returning to the terminal 
in the afternoon. Stratus will return to the terminal area late 
Wednesday night through early Thursday morning.

SFO Bridge Approach... Stratus may impact the approach path a 
little later than at the terminal tonight. Otherwise similar to SFO.

Vicinity of OAK and SJC... Stratus has taken hold at OAK with the 
breezy west winds diminishing through the evening. At SJC, there is 
low to moderate confidence on the timing of stratus impacts as 
radiational development is possible, but should no radiative stratus 
develop, MVFR ceilings should develop around 10-12Z. Stratus will 
dissipate in the afternoon with breezy northwest winds developing at 
OAK. Confidence in the wind direction and speed is lower at SJC for 
Wednesday afternoon as the terminal sits between a northwest flow 
from SF Bay and downsloping winds from the Santa Cruz Mountains. 
Have opted to lean more towards the climatological diurnal wind, but 
may need to carefully monitor observations and future TAF updates 
through the day. Stratus will return to OAK sometime late Wednesday 
night through Thursday morning.

Monterey Bay Terminals... MVFR-IFR stratus through the night into 
Wednesday morning as breezy winds continue to diminish through the 
evening and early overnight hours. Stratus should retreat to the 
immediate coast on Wednesday morning with the breezy onshore winds 
resuming in the afternoon, coming from the west at MRY and the 
northwest at SNS. Wednesday evening, stratus flow could impact SNS 
as early as 00-02Z, and MRY soon after.

&&

.MARINE...
(Tonight through next Monday)
Issued at 958 PM PDT Tue Jun 16 2026

Fresh to strong north winds across the northern outer waters
result in hazardous seas through tomorrow morning. However,
onshore pushes will bring moderate to fresh south to southwest
winds for the San Pablo and San Francisco Bays during the
afternoon and evening hours, as well as near the coast from Point
Sur north to Point Pinos and Pigeon Point to the Golden Gate.
Otherwise, generally light to gentle winds into the weekend. Seas
will remain slight to moderate into the weekend with a low south-
southwesterly swell across most of the coastal waters.

&&

.BEACHES...
Issued at 1245 AM PDT Wed Jun 17 2026 

Long period southerly swell at around 15 to 17 seconds will persist 
through early Thursday as energetic storms in the Southern 
Hemisphere continue to affect the California coast, especially for
south and southwest facing beaches. Hazardous beach conditions 
are advertised, specifically for moderate to steeply sloped 
beaches along the Pacific Coast of the North Bay, San Mateo, Santa
Cruz counties. A Beach Hazards Statement for Pacific Coast 
beaches continues through 5 AM Thursday morning. Be sure to check 
beach conditions before you head out. Sneaker waves will run up 
the beach much farther than other waves, potentially catching 
beachgoers by surprise and resulting in people being swept into 
the water. Rip currents are strong enough to pull the strongest 
swimmers away from shore. Swim near a lifeguard if possible. Stay 
back from the beach, and away from jetties, piers, beachside 
rocks, and other infrastructure near the water. Never turn your 
back to the ocean! 

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through late Wednesday night for CAZ006-
     505-509-529-530.

     Coastal Flood Advisory until 5 AM PDT Thursday for CAZ006-506-
     508.

     Coastal Flood Advisory until 5 AM PDT Wednesday for CAZ505-509-
     529-530.

PZ...Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Tangen
LONG TERM....Tangen
AVIATION...DialH 
MARINE...DialH

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Prepared by Boulder-Creek.com Weather at: Wed Jun 17 02:30:03 PDT 2026