FXUS66 KMTR 120052
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
552 PM PDT Sat Jul 11 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1253 PM PDT Sat Jul 11 2026
- Warmer and drier conditions continue into early in the week
with Moderate HeatRisk returning
- 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
tonight through Monday
&&
.SHORT TERM...
Issued at 1253 PM PDT Sat Jul 11 2026
(This evening through Sunday night)
Not much change to the forecast over the past 24 hours. Seeing
high clouds advect northward across the region early this
afternoon, evident of the monsoonal moisture advancing northward.
Given the marine layer compressing to around 500 feet, stratus has
quickly retreated to the coast and even clearing in spots over
the Pacific. This will give way to more sunshine (minus the high
clouds) and allow temperatures to warm into the 60s to lower 70s
near the coast, lower-to-upper 70s just inland, with 80s to lower
90s across the interior. Some of the warmest interior areas will
reach into the mid- to-upper 90s.
For tonight, mid/upper level moisture will continue to increase
with Precipitable Water (PW) values reaching between 1.00-1.25"
across the Bay Area and Central Coast as the high pressure aloft
gradually shifts towards the Intermountain West. Thus, cannot rule
out some high-based rain showers, sprinkles, or virga
(precipitation not reaching the surface) given the dry layer
between the marine layer and about 10,000 feet.
On Sunday, temperatures will be similar to those this afternoon.
By Sunday night, PWs will increase further to between 1.10-1.30"
with minimal MUCAPE expected by most forecast models. However,
still looks like a marginal case for dry lightning (generally less
than 5-10%) given the lack of mid/upper level instability.
&&
.LONG TERM...
Issued at 1253 PM PDT Sat Jul 11 2026
(Monday through next Friday)
We continue to see the mid/upper level moisture and marginal
instability over the Bay Area and Central Coast. However, the
moisture profile aloft will deepen potentially resulting in
wetting (>0.10") rainfall. As we move toward the middle part of
the week, the moisture aloft is forecast to exit eastward as the
ridge aloft shift toward the Midwest.
As far as temperatures go, we are expecting a warming trend in
overnight minimum temperatures into early next week as a result of
the increased monsoonal moisture surge. This will result in
increased mid-to-high level clouds that will reduce the amount of
radiational cooling. This brings more widespread Moderate HeatRisk
to the region Monday and Tuesday before cooling of overnight
temperatures begin Tuesday night into Wednesday. Toward the latter
half of the week, troughing off of the Pacific Northwest coast
becomes the dominate feature allowing for a gradual cooling trend.
&&
.AVIATION...
(00Z TAFS)
Issued at 552 PM PDT Sat Jul 11 2026
Mid to high clouds including wispy cirrus, virga i.e. a few
isolated high based showers and a few areas of coastal stratus
and fog are seen based on satellite (and radar) and NWS spotter
observations. The marine layer depth varies from 500 to 1000 feet
late this afternoon. Southerly winds aloft will continue to
transport mid to high clouds along with occasional mid level
instability during the 00z TAFs. Increasing cloud cover will slow
radiative cooling and redevelopment of stratus and fog tonight and
generally result in a hazy, partly cloudy sky Sunday. Overall
conditions favor VFR with occasional LIFR-IFR possible mainly
along the immediate coastline.
Vicinity of SFO...VFR. Northwest to west wind 20 knots diminishing
to 10 knots tonight and Sunday morning, then increasing to near 15
knots Sunday afternoon and early evening.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Winds varying from northwest to
southwest 5 to 15 knots.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 449 PM PDT Sat Jul 11 2026
Locally hazardous conditions persist over the outer waters north
of the Golden Gate thanks to moderate to fresh northerly winds.
Elsewhere light to moderate northerly winds prevail. A moderate
northwesterly swell will remain as well. Winds and seas build by
the middle of next week.
&&
.FIRE WEATHER...
Issued at 1253 PM PDT Sat Jul 11 2026
Warm and dry conditions persist through much of the upcoming
week, especially away from the coastal marine influences which are
forecast to persist. This will increase fire weather concerns as
fuels rapidly dry out due to low humidities. Fire weather concerns
further increase late this weekend into early in the upcoming
week as a surge of monsoonal moisture advects northward around the
western periphery of the high pressure over the Desert Southwest
and Intermountain West. 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.
RGass
&&
.BEACHES...
Issued at 453 AM PDT Sat Jul 11 2026
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...Coastal Flood Advisory until 4 AM PDT Thursday for CAZ006-506-
508.
Coastal Flood Advisory from 8 PM this evening to 4 AM PDT
Wednesday for CAZ505-509-529-530.
PZ...Small Craft Advisory until 3 PM PDT Tuesday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Canepa
MARINE...MM
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Prepared by Boulder-Creek.com Weather at: Sat Jul 11 18:30:04 PDT 2026
From the National Weather Service
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