FXUS66 KMTR 202043
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
143 PM PDT Sat Jun 20 2026

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

.KEY MESSAGES...
Updated at 1245 AM PDT Sat Jun 20 2026

 - Hazardous beach conditions with increased risk of sneaker waves
   and strong rip currents continue through the extended forecast

 - Minor HeatRisk with below normal temperatures through the 
   weekend

 - Warmer temperatures and Moderate HeatRisk concerns return by 
   midweek across the interior

&&

.SHORT TERM...
Issued at 109 PM PDT Sat Jun 20 2026
(This evening through Sunday)

What a difference 24 hr makes, warmer conditions and increased 
sunshine. Afternoon visible satellite shows a well defined 
circulation spinning off the Central Coast. The nearby 
circulation, weaker marine layer inversion, and departing upper 
level trough led to increased sunshine along the coast and earlier
clearing of AM clouds.

The rest of the weekend will feature rather nice sensible weather.
Not a bad Father's Day weather wise. A weak shortwave upper level
ridge will nose in late tonight and Sunday. The marine layer won't
completely go away tonight, but it will be slightly more
compressed due to building 500mb heights. Even with it being more
compressed we will still a solid inland intrusion with clouds
covering much of the inland valleys. Morning marine layer will
roll back to the coast mid-morning, but coastal areas may struggle
to get any clearing tomorrow. Away from the coast temps will climb
a few more degrees with highs in the 70s to mid 80s. 


&&

.LONG TERM...
Issued at 109 PM PDT Sat Jun 20 2026
(Sunday night through next Friday)

Long range forecast remains on track with the evolution of the
longwave pattern. The large upper level area of high pressure over
the Desert SW/N Mexico will strengthen and nudge northward. The
building high will continue to compress the marine layer and
continue the warming and drying trend. At this point the two 
warmest days appear to be Tuesday/Wednesday with highs 60s/70s 
coast/bays and 80s/upper 90s interior. The warming trend will also
cause an uptick in HeatRisk back into Moderate category. Coverage
of Moderate HeatRisk does not seem widespread enough to warrant a
Heat Advisory at this point, but we'll be messaging heat impacts 
regardless. To round out the rest of the work week temperatures 
begin to moderate and then cool. 

Previous discussions mentioned low chance high impact thunderstorm
scenario next week, but latest model trends show this being less
likely. Longer range guidance still shows a surge of higher PWATs
moving north along Baja, but instead of continuing north they
drift more NE. We'll still monitor, but chance for thunder is
looking less.

&&

.AVIATION...
(18Z TAFS)
Issued at 1139 AM PDT Sat Jun 20 2026

Widespread VFR conditions except for HAF where it will remain MVFR 
no later than 21Z today. Thereafter, VFR at all terminals through 
the afternoon as onshore moderate winds increase to around 12-15kt. 
The marine layer will return tonight after 04-06Z Sunday bringing 
low-end MVFR ceilings (BKN011-015) to most terminals. Low confidence 
on whether cloud bases will dip below 1000 feet, though the marine 
layer will be compressed tonight (between 1000-1500 feet) compared 
to previous nights. The stratus is expected to scatter out by 16-18Z 
Sunday.

Vicinity of SFO...VFR with gentle SW breezes through the late 
morning. Westerly winds increase to moderate breezes by 21Z and 
continue into evening hours. Medium confidence on timing of stratus 
tonight as it may arrive some time between 06-08Z. Onshore winds 
also ease with the arrival of the marine layer.

SFO Bridge Approach...Moderate winds around 12-14 kt will remain 
more W to NW through the afternoon with gusts up to 20 kt. These 
winds ease by 06Z Sunday. MVFR stratus is expected to arrive roughly 
an hour later than SFO (07Z Sunday) and scatter out at the same time 
(17Z Sunday).

Vicinity of OAK and SJC...VFR as west to northwest winds increase to 
around 14 kt by 21Z today. Higher chance for SJC to experience some 
gusts up to 20 kt this afternoon. The marine layer will impact both 
terminals tonight as early as 06Z at OAK and 10Z at SJC with 
ceilings around 1200-1500 feet. Onshore winds ease overnight and 
increase by Sunday late morning. SJC is expected to have their MVFR 
ceilings scatter out as early as 16Z followed by OAK at 18Z.

Monterey Bay Terminals...Onshore winds increase this afternoon with 
SNS experiencing moderate breezes around 14 kt and MRY remaining 
gentle (~10 kt). The coastal stratus deck will impact both terminals 
by 08Z Sunday, though there is medium confidence on the exact timing 
as they may roll in as early as 06Z. Ceilings will be lower than 
last night due to a compressed marine layer. Low confidence on 
whether they will dip into IFR status, but most likely will be on 
the borderline. 

&&

.MARINE...
(Today through Thursday)
Issued at 858 AM PDT Sat Jun 20 2026

Light winds today will increase across the northern outer waters
later tonight and persist through early Monday morning, leading to
hazardous conditions for small craft. Elsewhere across the inner
and outer waters winds will remain light to moderate. Long period
southwest swell is likely to continue through the forecast period.

&&

.BEACHES...
Issued at 308 AM PDT Sat Jun 20 2026

Long period southerly swell at around 15 to 17 seconds will
persist for the remainder of the weekend, and increase to 17 to 
19 seconds by the middle of the upcoming work week 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 Wednesday
afternoon. 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 Wednesday afternoon for CAZ006-
     505-509-529-530.

PZ...Small Craft Advisory from 9 PM this evening to 3 AM PDT Monday 
     for Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...Navarrete
MARINE...DM

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Prepared by Boulder-Creek.com Weather at: Sat Jun 20 14:30:02 PDT 2026