FXUS66 KMTR 170705
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1205 AM PDT Mon Aug 17 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1201 AM PDT Mon Aug 17 2026
- Shallower marine layer through midweek
- Minor fluctuations in temperatures this week
&&
.SHORT TERM...
Issued at 1201 AM PDT Mon Aug 17 2026
(Today and tonight)
Quiet weather today with little to no impactful weather expected
through the next week. Temperatures today will be near or slightly
below normal for this time of year with slightly more mild overnight
lows to wake up to this morning than we've seen the last few days
due to mid/high level cloud cover insulating radiative cooling. The
mid to high level cloud cover will continue out ahead of a
persistent troughing pattern over the EPAC. The additional cloud
cover may impact daytime highs as well, limiting peak day heating
somewhat. Some patchy fog and drizzle may be possible as well,
especially right along the coastline.
&&
.LONG TERM...
Issued at 1201 AM PDT Mon Aug 17 2026
(Tuesday through Sunday)
Slight shifting in the persistent troughing over the EPAC and the
upper level ridging over the Four Corners region will result in
subtle warming Tuesday and Wednesday, as the upper ridge pushes
west slightly. The troughing pushes back to the east for the
remainder of the week, cooling temperatures a few degrees.
Overall, temperatures will be on the cooler side of normal for a
majority of forecast period. There is no clear signal for a
significant pattern change through the extended forecast.
&&
.AVIATION...
(06Z TAFS)
Issued at 1004 PM PDT Sun Aug 16 2026
IFR-LIFR stratus is being observed at coastal terminals, but the
spatial extent is unclear owing to widespread high clouds blocking
satellite observation. The overnight stratus forecast is moderate
confidence with the current forecast leaning towards IFR-LIFR
stratus expanding across the region and the inland valleys, before
stratus retreats back to the immediate coastal regions through
Monday morning. May need to monitor for the stratus not developing
to the previously forecast extent with high clouds preventing
radiational cooling overnight. Light winds prevail into Monday
morning before moderate onshore winds resume Monday afternoon.
Vicinity of SFO... VFR with high clouds at present. Moderate
confidence that IFR stratus returns within the next few hours with
low confidence on the exact timing, with high resolution model
output showing the stratus deck right at the edge of the terminal.
Stratus clears out late Monday morning with breezy onshore winds
resuming in the afternoon. Stratus returns Monday evening and
overnight with moderate confidence on the timing of the stratus.
SFO Bridge Approach... Similar to SFO.
Monterey Bay Terminals... IFR-LIFR conditions persist overnight with
stratus clearing at SNS late Monday morning, while confidence in a
scattering of the ceilings at MRY during the afternoon and evening
hours remains low to moderate. Stratus begins to expand again early
Monday evening, including over SNS. Light winds persist through
Monday morning before moderate onshore winds resume Monday
afternoon.
&&
.MARINE...
(Tonight through next Saturday)
Issued at 857 PM PDT Sun Aug 16 2026
Northwesterly gentle to moderate breezes persist with localized
fresh gusts across the inner coastal waters. Winds increase to
fresh to strong breezes late Monday and remain elevated through
the end of the forecast period. Seas of around 4 to 6 feet will
build to 7 to 8 feet by Tuesday and Wednesday. A long period
southerly swell around 14 to 16 seconds will continue to subside
through the early work week.
&&
.FIRE WEATHER...
Issued at 1205 AM PDT Mon Aug 17 2026
Nocturnal drying through at least mid-week as the marine layer
gradually compresses. Expect more widespread fair to moderate
recoveries developing over the higher elevations, especially in
and around the Timber Fire.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
SHORT TERM...JM
LONG TERM....JM
AVIATION...DialH
MARINE...DialH
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Prepared by Boulder-Creek.com Weather at: Mon Aug 17 02:30:03 PDT 2026
From the National Weather Service
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