FXUS66 KMTR 101154
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
454 AM PDT Fri Jul 10 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1200 AM PDT Fri Jul 10 2026
- Warmer temperatures continue into next week with Moderate
HeatRisk early next week
- Long period southwest swell causes an increased risk of sneaker
waves and strong rip currents through this evening
- 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
&&
.SHORT TERM...
Issued at 1200 AM PDT Fri Jul 10 2026
(Today and tonight)
Stratus returns tonight with satellite imagery showing it already
extending into the SF Bay shoreline and along most of the
coastline/Monterey Bay region. The overall stratus footprint is more
compressed tonight compared to last night. This is a result of
building high pressure over southern California compressing the
marine layer (and limiting stratus' inland progression). Yesterday
the marine layer was closer to 1500 feet while tonight it is closer
to 1000 ft. What does that mean for you? Coastal residents may see
patchy drizzle and foggy conditions early this morning before
conditions improve heading into the afternoon. For interior
residents, stratus coverage will continue to expand overnight but it
is not forecast to be as expansive in nature as it was the previous
few nights.
Temperatures stay fairly seasonal across the interior today with
highs in the 80s to low 90s in the hottest locations. For coastal
areas, temperatures continue to run cooler than normal with highs in
the upper 50s to 60s and in the 70s along the SF Bay shoreline. The
interior Central Coast remains the hottest portion of our CWA with
highs in the upper 90s to low 100s expected. Minor HeatRisk
continues across the interior with Moderate HeatRisk forecast across
the higher elevations of the interior Central Coast.
&&
.LONG TERM...
Issued at 1200 AM PDT Fri Jul 10 2026
(Saturday through Thursday)
A warming trend continues this weekend into next week as high
pressure builds across the western United States. Upper level high
pressure will gradually strengthen and shift northeastward from
southern California towards the Intermountain West Saturday into
Sunday. Building high pressure aloft will keep the marine layer
compressed to around 1000 ft for much of the extended forecast and
bring a return of seasonally warm temperatures across the interior.
Coastal areas, however, will stay seasonal to seasonally cool thanks
to the marine layer not entirely mixing out/remaining compressed
along the coastline. Interior high temperatures will be in the 80s
to 90s this week with the interior Central Coast and far interior
East Bay reaching the low 100s. Coastal areas will stay in the 60s
to 70s. Tuesday and Wednesday look to be the warmest days of the
week next week as upper level ridging strengthens over the central
United States. Given the strength of the upper level ridge,
temperatures may be adjusted upwards by a few degrees as we get
closer in time. Moderate HeatRisk becomes more widespread Monday
through Wednesday across both the higher elevations and more urban
areas. Heat products may necessary for portions of the interior
early next week. As temperatures heat up, remember to take breaks in
the shade and stay hydrated if spending prolonged periods of time
outdoors.
Thunderstorms remain possible Sunday into Monday but confidence in
their development continues to be low. The monsoonal moisture
remains on track to arrive overnight Sunday into Monday with
instability continuing to be the limiting factor for storm
development. Model guidance shows the best 700-500 mb lapse rates (7-
8C/km) Sunday afternoon while the bulk of the monsoonal moisture
does not arrive until Monday. Model guidance continues to show
minimal MUCAPE across the Central Coast and portions of the Bay Area
during this period. The lack of instability would cap storm
development and keeps the likelihood of thunderstorms low. That
being said, this is considered a low probability, high impact
scenario where if a thunderstorm is able to develop, the fire
weather threat is high. High resolution models will get within range
of this event starting Friday. It will be interesting to see how
they are modeling instability with this event and how that
influences the thunderstorm potential. Recent ensemble guidance
suggests that light rain may be possible with any storms that are
able to develop. This is mainly limited to the ECMWF with the GFS
ensemble members still showing almost no rainfall.
&&
.AVIATION...
(12Z TAFS)
Issued at 434 AM PDT Fri Jul 10 2026
The marine layer has continued to be gradually compressed by
building high pressure, so not as widespread with lower ceilings
and less predictable than the past few mornings with lighter
winds. Most terminals should continue to hover around their
current flight category before clearing out by late morning but
some amendments are likely.
Vicinity of SFO...Stratus has shifted just W/NW of the terminal
with clear conditions along the southern Bayshore. A TEMPO group
is in the TAF through 16z for MVFR/IFR ceilings. Clearing is
expected by mid morning with VFR until late tonight.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...IFR/LIFR ceilings are expected to persist
through late morning at least for both terminals and possibly into
early afternoon for KMRY. Expect MVFR/IFR ceilings to return by
sunset with occasionally breezy onshore winds this afternoon.
&&
.MARINE...
(Today through Wednesday)
Issued at 434 AM PDT Fri Jul 10 2026
Northwest seas will be rough (9-11 ft) through the weekend and
begin to subside to moderate (6-8 ft) by the beginning of next
week. Strong northwesterly, near gale at times, will begin to
diminish tonight with fresh breezes and strong gusts returning
Sunday.
&&
.FIRE WEATHER...
Issued at 450 AM PDT Thu Jul 10 2026
Warmer and drier conditions continue through early next week. This
increases fire weather concerns slightly as fuels are forecast to
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 limiting factor is the lack of instability
over our region those days. Thus, we will continue to closely
monitor these conditions through the weekend. Given the
combination of the potential for dry lightning and rapidly drying
fuels, it is important to stay up to date on the forecast as it
evolves. This is a low confidence, low probability but
potentially high impact scenario.
&&
.BEACHES...
Issued at 450 AM PDT Thu Jul 10 2026
A Beach Hazards Statement remains in effect for Pacific coast
beaches through this 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 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 and in January we reached 2.5 feet
above normal.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through this afternoon for CAZ006-505-
509-529-530.
Coastal Flood Advisory until 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 Sunday for Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
to Pt Pinos 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.
Small Craft Advisory until 3 PM PDT Monday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...JM
MARINE...JM
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Prepared by Boulder-Creek.com Weather at: Fri Jul 10 06:30:03 PDT 2026
From the National Weather Service
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