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NWS Technical
Weather Discussion |
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FXUS66 KMTR 091959
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1259 PM PDT Thu Jul 9 2026
...New SHORT TERM, LONG TERM, FIRE WEATHER...
.KEY MESSAGES...
Updated at 1256 PM PDT Thu Jul 9 2026
- Warmer temperatures persist through early next week
- 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
&&
.SHORT TERM...
Issued at 1256 PM PDT Thu Jul 9 2026
(This evening through Friday night)
High pressure strengthening across southern California will build
northeastward over the Desert Southwest over the weekend. As such, a
gradual warming and drying trend is forecast through the weekend and
into early next week. 850 mb temperatures look to reach between 23-
25 degrees C during this timeframe. However, generally Minor
HeatRisk are expected with pockets of Moderate HeatRisk across the
far interior areas through the weekend. Thus, afternoon maximum
forecast temperatures today will be in the 60s near the coast,
60s/70s around the bays, and 80s to middle 90s inland. Meanwhile,
the warmest interior locations of the Monterey County have a greater
than 60% probability of reaching 100 degrees F.
Tonight, expecting mist/light drizzle to impact the coast at times
with low clouds forecast to push locally inland into the valleys.
However, widespread rainfall is highly unlikely. That said, not
expecting as widespread coverage as this morning with the marine
layer forecast to compress. Temperatures for Friday will be similar
to those this afternoon. Friday night looks to be more of the same,
low clouds near the coast will return back inland with temperatures
generally in the 50s across the lower elevations. However, the
building high pressure over the Desert Southwest will result in
warmer temperatures in the higher elevations where 60s to lower 70s
are expected.
&&
.LONG TERM...
Issued at 1256 PM PDT Thu Jul 9 2026
(Saturday through next Wednesday)
We are still expecting mid/upper level moisture to be advected
northward as southerly winds aloft on the periphery of the high
pressure over the Desert Southwest. This will be most notable Sunday
into Monday and potentially lasting through Tuesday night. However,
the limiting factor remains instability at those levels with MUCAPE
forecast to remain less than 500 J/kg based off of the latest CAMs.
That said, the GFS has little to no CAPE across our region, yet the
mid/upper level moisture looks highly likely. So the threat for high
based convection still appears to be low at this time. We'll
continue to monitor the higher resolution models with each
subsequent model run(s) for the potential high based convective.
By Monday and Tuesday we begin to see more Moderate HeatRisk across
the interior. This is as overnight lows are forecast to increase as
a result of the building high pressure early next week. That said,
mid/upper level cloud cover (as a result of the mid-level sub-
tropical/tropical moisture) may limit surface heating. However,
onshore winds and a shallow marine layer will remain present,
keeping conditions cooler near the coast. In the extended, high
pressure is forecast to remain parked over the Desert Southwest with
troughing off of the Pacific Northwest coast.
&&
.AVIATION...
(18Z TAFS) Issued at 1155 AM PDT Thu Jul 9 2026
W-NW flow brought stratus overnight but the vast majority has
since mixed out leaving VFR for all terminals except MRY and HAF.
The W-NW flow will likely be stronger today as the pressure
gradient tightens over the coastal waters resulting in wind
speeds higher than yesterday at most terminals. Stratus will
return overnight as the onshore flow persists with IFR to LIFR
conditions likely at most terminals into Friday morning.
Vicinity of SFO...Skies have cleared as SFO and VFR should persist
through the remainder of the day. W-NW winds gusting over 20 mph
can be expected this afternoon. MVFR or IFR ceilings will return
once again soon after sunset.
SFO Bridge Approach...Skies will remain clear today with a return
of MVFR/IFR ceilings overnight.
Monterey Bay Terminals...LIFR ceilings continue at MRY with an
eddy spinning over the bay pushing stratus toward the coast.
There is a 50/50 chance of a short window of VFR by mid-
afternoon, then IFR/LIFR returns after sunset through the
remainder of the forecast period. SNS has cleared and will see
several hours of VFR today followed by a return of IFR ceilings in
the evening.
&&
.MARINE...
(Today through Tuesday)
Issued at 425 AM PDT Thu Jul 9 2026
Fresh to strong northwest winds continue, increasing to near gale
force heading into the weekend. Wind driven rough seas (9-11 ft)
will persist into the weekend along with a long period southerly
swell.
&&
.FIRE WEATHER...
Issued at 1256 PM PDT Thu Jul 9 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.
&&
.BEACHES...
Issued at 425 AM PDT Thu Jul 9 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 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 this afternoon 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 3 PM PDT Sunday for Pt Arena to Pt
Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 3 AM PDT Friday for Pt Reyes to
Pigeon Pt 0-10 nm.
Small Craft Advisory until 9 PM PDT Friday 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.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...RA
MARINE...Navarrete
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Prepared by Boulder-Creek.com Weather at: Thu Jul 9 14:30:04 PDT 2026
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From the National Weather
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reserved Boulder-Creek.com. |
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Revised:
29 Mar 2008 09:53 -0800 GMT
(Pacific) |
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