FXUS66 KMTR 121212
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
503 AM PDT Fri Jun 12 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1215 AM PDT Fri Jun 12 2026
- Hot and dry through today for interior locations with a
moderate risk of heat-related illnesses
- Minor coastal flooding due to higher than normal high tides
anticipated across coastal regions of the San Francisco Bay
Area
- Increased risk of sneaker waves and strong rip currents along
south- and southwest-facing beaches this weekend
&&
.SHORT TERM...
Issued at 1215 AM PDT Fri Jun 12 2026
(Today and tonight)
GOES-West nighttime microphysics imagery reveals a much-welcomed
surge of stratus returning to Pacific coastal locations since the
evening hours. This has resulted in broken/overcast skies to
communities such as Monterey, Salinas, Santa Cruz, and Half Moon
Bay, as well as the western half of San Francisco. Areas of fog
have also been reported. Some locations in the Santa Cruz
Mountains are running 10-15 deg F cooler compared to 24 hours
ago. Following a hot day for interior areas, temperatures have
been running generally a few to several degrees warmer.
Upper-level ridge remains the dominate synoptic feature over the
eastern Pacific. For Friday, areas covered in Moderate HeatRisk
will be primarily reduced to interior locations of the East Bay
and South Bay. For these locations, the Heat Advisory continues
through Friday evening. Temperatures will continue to moderate
region-wide on Saturday.
High tide flooding will occur nightly along the Bayshore through
the middle of next week. The combination of an upcoming new moon
and lunar perigee on Sunday, and about 7 inches of additional
tidal anomaly from a combination of storm surge, thermal expansion
of the Eastern Pacific, and about 2 inches inches of Sea Level
Rise since the vertical datums were established in the 80s and 90s
will add up to bring tides up to 1.8 feet above normal through
the weekend. While lower than the historic tidal flooding in
January (peaked at 2.6 ft) the tides this weekend could end up
being the highest observed in the Summer, beating the current
record of 1.7 ft from July 2022.
&&
.LONG TERM...
Issued at 1215 AM PDT Fri Jun 12 2026
(Saturday through Thursday)
A short-wave trough will cut along the outer periphery of the
eastern Pacific ridge over the weekend. This will promote further
cooling for interior locations into the second half of the
weekend. Coastal locations can expect the usual June stratus.
While temperatures will return closer to middle-June climatology,
the main hazards will be the southerly swell along the coast, plus
the coastal flooding associated with the high tides
&&
.AVIATION...
(12Z TAFS)
Issued at 503 AM PDT Fri Jun 12 2026
Coastal stratus and fog /IFR-VLIFR/ stretches from coastal Sonoma
County southward along the Big Sur Coast. Stratus and fog are
reaching in through the Golden Gate to the East Bay. Stratus and
fog also stretches into the Salinas Vally. Elsewhere inland it's
VFR. Radiative cooling until daybreak will likely result in patchy
morning valley stratus and fog /IFR-LIFR/. The marine layer depth
is ~ 1300 feet. Within the marine layer temperature inversion it
is still warm at this hour with 70s to lower 80s. Diurnal surface
warming and vertical mixing will improve ceilings and visibilities
to MVFR-VFR back near the coastline today. High resolution model
output shows coastal stratus and fog /IFR-LIFR/ redevelop tonight
and Saturday morning. Winds will be primarily onshore during the
12z TAFs.
Vicinity of SFO...Low to moderate confidence VFR through daybreak.
A greater amount of water vapor per higher surface dew point temps
have arrived while surface temperatures have trended cooler. This
combining with radiative cooling may result in a patch or two of
low stratus and/or fog until about daybreak. The 12z SFO TAF for
the time being advertises VFR, will amend as needed. VFR for late
morning, afternoon and evening. Stratus /IFR/ is forecast for
tonight and Saturday morning. West to northwest wind 5 to 12
knots.
SFO Bridge Approach...Similar to SFO.
Vicinity of SJC and OAK...Residual southerly winds from yesterday's
robust southerly surge of wind and stratus is still going at KSJC.
5 am pressure gradient SNS-SJC was 1.7 mb. It may take time i.e.
until late morning or perhaps early afternoon for a wind shift to
northwesterly at SJC today. The temp/dew point temp difference is
still fairly large at this hour, likely enough to get through
daybreak without patchy stratus and/or fog to form, however will
monitor and amend TAF as needed. For OAK Airport, stratus and/or
fog is nearby; tempo group indicated for morning stratus /LIFR/
until 16z. Otherwise VFR today, then stratus /IFR/ redevelops
tonight and Saturday morning. Northwest wind 5 to 10 knots.
Monterey Bay Terminals...Stratus and/or fog /IFR-VLIFR/ through
much of the morning, improving conditions to MVFR-VFR during the
afternoon. Stratus and/or fog /IFR-LIFR/ redevelop and move inland
tonight and Saturday morning. Mainly onshore winds 5 to 15 knots.
&&
.MARINE...
(Today through Wednesday)
Issued at 412 AM PDT Fri Jun 12 2026
Small craft advisory conditions linger in the northern outer
waters while winds overall will diminish to moderate to gentle
breezes through the weekend and early next week. Seas will subside
through early next week.
&&
.BEACHES...
Issued at 1241 PM PDT Thu Jun 11 2026
Long period southerly swell will continue through the weekend,
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. Be sure 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...Coastal Flood Advisory until 3 AM PDT Wednesday for CAZ006-506-
508.
Heat Advisory until 7 PM PDT this evening for CAZ510-513>515.
PZ...Small Craft Advisory until 3 AM PDT Saturday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Rowe
LONG TERM....Rowe
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Fri Jun 12 06:30:03 PDT 2026
From the National Weather Service
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