FXUS66 KMTR 180456
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
956 PM PDT Fri Jul 17 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1225 PM PDT Fri Jul 17 2026
- Cooler and more humid conditions through early next week
- The marine layer prevails through the weekend
&&
.SHORT TERM...
Issued at 1225 PM PDT Fri Jul 17 2026
(This evening through Saturday night)
A marine layer around 1,200 feet in depth resulted in inland
intrusion of stratus overnight. That said, current satellite
trends are show these clouds doing their typical afternoon retreat
to the coast. Afternoon temperatures will be as much as 10 deg F
below seasonal average, especially in the lower elevations.
Overnight, expecting stratus to return to the coast this evening
and penetrate into the inland valleys into early Saturday morning.
This is typical for the month of July. Once low clouds retreat
back to the coast by mid-to-late morning on Saturday, mostly sunny
skies are forecast for the afternoon highs again slightly below
average. Rise and repeat for Saturday night.
&&
.LONG TERM...
Issued at 1225 PM PDT Fri Jul 17 2026
(Sunday through next Thursday)
Still keeping an eye on conditions late this weekend into early
next week as there is some uncertainty with regards to the
placement of the ridge to the east and troughing to the west. The
location of these feature will ultimately drive how much mid-to-
upper level moisture we receive from the tropics and monsoon. We
will continue to monitor this moisture and Convection-Allowing
Models (CAMs) over the weekend to see if their are any singles for
convection. Be sure to check back for the latest forecast
information.
&&
.AVIATION...
(06Z TAFS)
Issued at 948 PM PDT Fri Jul 17 2026
MVFR-IFR conditions across the interior with the potential for fog
and LIFR conditions directly along the coast. Stratus is expected
to fill in across the region over the next 2-3 hours with patchy
stratus potentially reaching LVK during the early morning hours.
Highest confidence in MVFR CIGs across the region due to the
depth of the marine layer but models indicate IFR conditions may
be possible later tonight. Fog is possible along the coast with
the potential for dense fog to form. Expect interior clearing by
mid to late morning with clouds sticking around longer along the
coast. Diurnally breezy winds continue during the
afternoon/evening with lighter winds overnight.
Vicinity of SFO...MVFR-IFR conditions overnight. Stratus will
remain in place over SFO through mid to late morning with a low
potential for fog to develop during the early morning hours.
Breezy afternoon/evening winds before an early return of stratus
during the evening hours.
SFO Bridge Approach...Stratus is taking longer to fill in over the
bay than over OAK or SFO. Guidance indicates stratus should fill
in over the SFO bridge approach by the early morning hours then
clear by mid/late morning.
Monterey Bay Terminals...IFR-LIFR conditions possible overnight.
High resolution guidance highlights the potential for reduced
visibilities and fog tonight with fog more likely after 12Z. TAFs
are more optimistic with clearing between 18-20Z but there is some
uncertainty as to it MRY will clear. Breezy afternoon/evening
onshore winds continue before weakening overnight.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 948 PM PDT Fri Jul 17 2026
Winds have eased across the coastal waters with occasional fresh
to strong gusts possible across the far northern outer waters and
along the Big Sur coast through early Saturday. Moderate seas and
moderate winds continue through midweek. Southerly swell will
increase along the coast next week due to Tropical Storm Elida
moving northwards in the eastern Pacific.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Saturday for Pt Arena to Pt
Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Kennedy
MARINE...Kennedy
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Prepared by Boulder-Creek.com Weather at: Fri Jul 17 22:30:04 PDT 2026
From the National Weather Service
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