FXUS66 KMTR 210352
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
852 PM PDT Sat Jun 20 2026
...New AVIATION, MARINE...
.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...
(06Z TAFS)
Issued at 852 PM PDT Sat Jun 20 2026
VFR conditions prevail due to carryover mixing within the boundary
layer from earlier in the day. A shallow cool front will move
southeastward along the CA coast, combining with post sunset
radiative cooling this will bring a return of stratus /MVFR-IFR/
tonight and Sunday morning. Thermal ridging will persist aloft
during the period. Patchy light coastal drizzle is possible
tonight and Sunday morning. Coastal stratus mixes out to MVFR-VFR
late Sunday morning and afternoon. Coastal stratus redevelops
Sunday night and Monday morning.
Vicinity of SFO...Stratus /MVFR/ is forecast to return to the
terminal. Stratus /MVFR/ and tempo light drizzle tonight and
Sunday morning. Conditions improve to VFR by 18z Sunday. Stratus
/MVFR/ returns by mid Sunday evening. West wind 11 to 18 knots
due to the incoming cool front tonight. West wind 15 to 25 knots
redeveloping by 21z Sunday afternoon, easing to near 10 knots mid
Sunday evening.
SFO Bridge Approach...Similar to SFO.
Vicinity of SJC and OAK...For SJC Airport VFR for the evening,
stratus /MVFR/ returns by 10z then mixes out to VFR by 18z Sunday.
Northwest wind 10 knots tonight becoming light southeasterly Sunday
morning. Northwest wind redeveloping Sunday afternoon. For OAK
Airport stratus /MVFR/ prevails tonight and Sunday morning, mixing
out to VFR by 18z. Also, tempo light drizzle 11z-15z Sunday. West
wind 5 to 15 knots.
Monterey Bay Terminals...Stratus /MVFR/ returns this evening,
stratus prevails with tempo light drizzle tonight and Sunday
morning. Conditions improving to VFR late Sunday morning and
afternoon. Stratus /MVFR-IFR/ returns Sunday evening and night.
Onshore winds 5 to 15 knots.
&&
.MARINE...
(Tonight through next Friday)
Issued at 843 PM PDT Sat Jun 20 2026
Fresh to strong winds in the northern outer waters now through
early Monday morning, leading to hazardous conditions for small
craft. Otherwise, across the inner and outer waters winds will
remain light to moderate. Long period southwest swell continues
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 until 3 AM PDT Monday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...MM
LONG TERM....MM
AVIATION...Canepa
MARINE...Malarkey
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Prepared by Boulder-Creek.com Weather at: Sun Jun 21 00:30:03 PDT 2026
From the National Weather Service
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