Technical NOAA Weather Discussion

FXUS66 KMTR 260453
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
953 PM PDT Thu Jun 25 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1233 PM PDT Thu Jun 25 2026

 - Gusty onshore winds today, increasing for Friday and Saturday
   with east-west mountain passes as high as 50+ mph and marine
   impacts through the weekend

 - An upper trough brings cooler temperatures, moisture, and a
   deeper marine layer with AM drizzle for Friday and Saturday 

 - Slow warming trend starting Sunday with near to slightly below 
   normal temperatures by early next week

&&

.SHORT TERM...
Issued at 1233 PM PDT Thu Jun 25 2026
(This evening through Friday night)

The marine layer mixed out a bit quicker today compared to 
yesterday, but satellite shows it stubbornly persisting across 
much of the north bay. Today is a transition period from the high 
pressure that brought above-normal temperatures earlier this week 
to a significant cool down that begins Friday with an approaching 
upper level low. Ahead of the system, a tighter gradient will 
increase winds across the region this afternoon with intermittent 
gusts up to 20-30 mph for many locations, higher in wind-prone 
passes. Temperatures will be similar to Wednesdays highs with 
coastal areas not warming much under a deeper marine layer and 
interior areas benefiting from slightly cooler 850mb temperatures 
as troughing returns. Heights continue to fall Friday with the 
marine layer deepening closer to 2000-2500 ft, significant enough 
for patchy drizzle Friday morning. Around the same time, winds 
will increase more substantially as the front moves through, and 
east- west passes could see gusts up to 50+ mph with many other 
locations gusting up to 25-35 mph. A much more significant 
cooldown is expected for Friday with temperatures falling 4-10 
degrees compared to Thursday for most locations outside of the 
immediate coast. Low clouds will likely struggle to clear out 
Friday afternoon with decent moisture in the lower levels and high
clouds will move in from north to south. 

The winds will increase not just for inland spots, but also for the 
coastal waters. More information can be found in the marine 
section below as well as the Small Craft Advisory that will be in 
effect for most zones through Friday evening. 

&&

.LONG TERM...
Issued at 1233 PM PDT Thu Jun 25 2026
(Saturday through next Wednesday)

Gusty onshore winds peak both Friday and Saturday as the low pushes 
down into Oregon, tightening the gradient further. Additional 
cooling is expected for Saturday with an even deeper marine layer
ushering in widespread coastal drizzle and pockets of light rain.
Saturday should be the coolest day of the forecast with clouds 
struggling to mix out in the afternoon and a slower trend to the 
movement of the low. While it meanders along the borders of 
CA/NV/OR, highs on Saturday should only reach the 50s and 60s for 
most spots, with low to mid 70s for interior areas, generally 
10-15 degrees below normal.

Things shift a bit Sunday as the aforementioned low starts to move 
up into Idaho and Montana and heights slowly increase. With this, 
the marine layer will begin to compress a bit each day into early 
next week, and temperatures will slowly warm back towards normal. 
General model trends are pushing temperatures higher for next week, 
but ensemble guidance continues to favor weak troughing prevailing 
which would keep us a bit cooler. Should the latter prevail, the 
coastal waters may continue to be impacted by gusty northwest winds 
through much of the week, with marine hazards potentially 
prevailing. 

&&

.AVIATION...
(06Z TAFS)
Issued at 910 PM PDT Thu Jun 25 2026

Stratus will continue to fill in across coastal and adjacent 
valley areas through the night. Mainly MVFR, locally IFR, 
conditions expected. Elevated onshore winds prevailing through the
night 15-25 kts at most terminals. Confidence increasing in BKN 
cigs remaining into Friday afternoon for some coastal TAF sates, 
including MRY and SFO, and potentially OAK. Similar bases Friday
night with increased chance for -DZ closer to the coast.

Vicinity of SFO...MVFR conditions prevailing. High confidence in 
winds gusting 15-25 kt through the night into early Friday 
afternoon (20-21z). Confidence increasing in MVFR conditions 
prevailing through Friday and night, including a chance of -DZ
after 06z Sat.

SFO Bridge Approach...Same general wind pattern as SFO, though 
moderate winds remain more NW-W with gusts up to 25kt. Similar
cloud pattern to SFO with increased chance of prevailing MVFR 
ceilings into the afternoon and evening on Friday. 

Vicinity of OAK and SJC...Moderate winds (10-15 kt) remaining 
from the west at OAK and NW at SJC, maintaining through the night
at OAK. MVFR ceilings at OAK...lower confidence in cigs reaching
SJC, most likely 12-18z Friday. Higher confidence of clearing at 
SJC late Friday morning; confidence increasing OAK stays MVFR
through Friday afternoon.

Monterey Bay Terminals...MVFR/IFR prevailing through the period. 
Ceilings will remain on the borderline of low end MVFR to high end
IFR and may jump between the two throughout the night. Moderate
confidence in scatter out at SNS; increasing confidence on MVFR 
cigs remaining through Friday afternoon at MRY. Chance for -DZ
late Friday night.


&&

.MARINE...
(Tonight through next Wednesday)
Issued at 848 PM PDT Thu Jun 25 2026

Fresh to strong breezes and rough seas will continue to develop
tonight and persist through the weekend. These strong winds and
rough seas will result in hazardous conditions for small craft
across most of the coastal waters at times through at least the
first half of next week. There is moderate confidence in at least
occasional gales developing across mainly the exposed coastal
waters over the weekend. Long period southwest swell will persist
through the extended forecast.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Saturday for Pt Arena to Pt 
     Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-SF Bay 
     N of Bay Bridge.

     Small Craft Advisory from 9 AM Friday to 3 AM PDT Saturday for 
     Mry Bay.

     Small Craft Advisory until 9 PM PDT Friday for Pt Reyes to 
     Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM to 9 PM PDT Friday for Pigeon Pt 
     to Pt Pinos 0-10 nm.

     Small Craft Advisory until 9 AM PDT Friday for Pigeon Pt to Pt 
     Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Zuber
LONG TERM....Zuber
AVIATION...APR
MARINE...Canepa

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea


  
Prepared by Boulder-Creek.com Weather at: Fri Jun 26 00:30:03 PDT 2026
From the National Weather Service