FXUS66 KMTR 081845
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1145 AM PDT Wed Jul 8 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 1229 AM PDT Wed Jul 8 2026
- A warming trend today through the weekend
- Long period southwest swell causes an increased risk of sneaker
waves and strong rip currents through Friday
- Coastal Flood Advisory for up to 1.7 feet of inundation above
ground level is possible in low-lying areas near shorelines and
tidal waterways
- Potential for thunderstorms and elevated fire weather concerns
late this weekend into early next week
&&
.UPDATE...
Issued at 923 AM PDT Wed Jul 8 2026
Stratus coverage is dissipating across the region at a much faster
pace than yesterday. Temperatures remain seasonal to seasonally
cool today with interior highs in the 80s and coastal/bay
shoreline highs in the 60s to 70s. The interior Central Coast
remains seasonally warm with highs in the 80s to 90s today. A
warming trend remains on track for tomorrow with interior high
temperatures in the upper 80s to 90s expected. Portions of the
interior Central Coast will be in the upper 90s to low 100s. We
continue to monitor the potential for thunderstorms late this
weekend into early next week.
&&
.SHORT TERM...
Issued at 1229 AM PDT Wed Jul 8 2026
(Today and tonight)
A 500 mb high pressure system centered over the southwestern
states is forecast to continue shifting essentially westward to
southern California and northern Mexico over the next 24 hours. A
500 mb trough of low pressure is over the eastern Pacific. Onshore
winds will continue to usher stratus inland through morning, with
diurnal surface warming mixing out much of the stratus by late
morning and afternoon. Daytime highs will be in the 60s coastside,
60s/70s bayside to the 80s/90s inland.
Stratus returns tonight. Lows will be in the 50s except lower to
mid 60s at higher elevations tonight.
&&
.LONG TERM...
Issued at 1229 AM PDT Wed Jul 8 2026
(Thursday through Tuesday)
The aforementioned high pressure system will be nearly stationary
on Thursday then it'll shift northeastward Friday through early
next week. Daytime highs will be coolest along the coast with 60s,
60s/70s bayside and in the 80s/90s inland to the lower 100s far
inland mainly over the southern interior. Night-time lows will
cool to the 50s/60s.
Southerly winds aloft on the periphery of the high will rather
quickly transport mid-level sub-tropical/tropical moisture to our
forecast area beginning Saturday evening and night. There are
hints in the GFS for example that a mid level moisture gradient
to our southwest will straddle the coastal waters and offshore
waters late Saturday/Sunday then again Tuesday. The intrusion of
dry air above lifting moist air parcels/layers tilt the lapse rates
much more steeply leading to convection. There may be a temporary
increase in mid level instability traversing our forecast area
early in the week. A sign for minimal potential, at this time at
least GFS forecast soundings are indicating essentially no
convective potential (mucape) over our forecast area.
&&
.AVIATION...
(18Z TAFS)
Issued at 1140 AM PDT Wed Jul 8 2026
Satellite is currently showing stratus clearing from most terminals.
Widespread VFR conditions are expected by 19-20Z today, except at
HAF where it will remain IFR-MVFR throughout the TAF period. A
northwest to west wind flow will persist at sites south of the
Golden Gate, meanwhile North Bay terminals experience southwest to
southerly winds. Fresh to moderate breezes are forecast between 10-
15 kt across our area. The marine layer returns again this evening
after 02-03Z Thursday with more borderline MVFR-IFR ceilings at most
terminals. Low to medium confidence (30-40% chance) on whether LVK
and SJC will develop MVFR ceilings as it is dependent on if the
marine layer deepens beyond 1000 feet.
Vicinity of SFO...MVFR ceilings are still hovering around the
terminal, but VFR conditions are expected to prevail after 19Z
today. Moderate breezes with embedded gusts increase through the
afternoon. MVFR ceilings begin to fill in around 05Z Thursday
followed by IFR ceilings around 08Z, which persist through 19Z
Thursday. Medium confidence on the arrival and scattering of the
stratus.
SFO Bridge Approach...Similar general pattern to SFO. Winds ease
slightly earlier and MVFR/IFR ceilings arrive shortly after SFO.
Ceilings are expected to scatter out before SFO Thursday morning
as well.
Monterey Bay Terminals...Stratus has cleared at MRY and SNS with VFR
expected to continue through this afternoon. Guidance is in
agreement that stratus will return early this evening (approx. 00-
03Z) and remain through late tomorrow morning. The marine layer will
lower to 1200-1000 ft tonight which may result in the marine layer
lowering to IFR overnight. LAMP guidance suggests LIFR conditions
and reductions in visibility are possible early tomorrow morning but
confidence is low to moderate. Breezy onshore winds are expected
this afternoon/evening before winds ease overnight.
&&
.MARINE...
(Today through Monday)
Issued at 923 AM PDT Wed Jul 8 2026
Rough seas with heights between 8-12 ft continue to build into the
weekend across the waters accompanied with a long period southerly
swell. Northwest fresh to strong breezes with near gale force
gusts persist into the weekend. Seas are expected to subside
slightly (8- 10 ft) next week.
&&
.FIRE WEATHER...
Issued at 430 AM PDT Wed Jul 8 2026
Warmer and drier conditions return Thursday and continue into this
weekend. This will increase fire weather concerns slightly as
fuels rapidly dry across the interior. Fire weather concerns
further increase late this weekend into early next week as a surge
of monsoonal moisture from the Gulf of California brings the
potential for high based convection to the region. If
thunderstorms are able to develop, dry lightning and gusty,
erratic outflow winds would be the main hazards. The current
pattern looks conducive for thunderstorms to develop but this may
change as the event gets closer in time. Given the combination of
potential for dry lightning and dry fuels, it is important to stay
up to date on the forecast for the latest information.
&&
.BEACHES...
Issued at 430 AM PDT Wed Jul 8 2026
A Beach Hazards Statement remains in effect for Pacific coast
beaches through Friday afternoon. Long period southwesterly swell
will create an increased risk of sneaker waves and strong rip
currents, as well as breaking waves up to 10 feet. This will be
especially true for south and southwest facing beaches with
moderate to steep slopes along the North Bay, San Francisco
Peninsula, and Santa Cruz coasts. Sneaker waves can sweep across
the shoreline without warning, pulling people into the sea from
rocks, jetties and beaches. Dangerous swimming and surfing
conditions and localized beach erosion can be expected. Stay off
of jetties, piers, rocks, and other waterside infrastructure.
Remain out of the water to avoid hazardous surf and NEVER turn
your back on the ocean. Monitor local weather, surf and tide
forecasts at www.weather.gov/mtr.
A Coastal Flood Advisory is in effect for minor high tide
flooding from Thursday July 9th through Thursday July 16th. The
combination of a perigean spring tide (lunar perigee on 7/13 and
new moon on 7/14) enhanced by 3-6 inches of additional water from
thermal expansion and accumulated sea level rise since the tidal
datum was established (1983-2001) will bring high tides up to 1.7
feet above normal. This will lead to minor flooding of parking
lots, parks and roads with isolated closures expected. For
context, in June we reached 2.0 feet above normal.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Friday afternoon for CAZ006-505-
509-529-530.
Coastal Flood Advisory from 4 PM to 4 AM PDT Thursday for CAZ006-
506-508.
Coastal Flood Advisory from 8 PM Saturday to 4 AM PDT Wednesday
for CAZ505-509-529-530.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.
Small Craft Advisory until 9 AM PDT Saturday for Pt Arena to Pt
Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt
Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 AM PDT Saturday for Pigeon Pt to Pt
Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...Navarrete
MARINE...Navarrete
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Prepared by Boulder-Creek.com Weather at: Wed Jul 8 14:30:03 PDT 2026
From the National Weather Service
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