FXUS66 KMTR 110745
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1245 AM PDT Tue Aug 11 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1245 AM PDT Tue Aug 11 2026
- Up to a 15% chance for elevated rain showers/thunderstorms
Wednesday across the Central Coast
- Cooling trend through Thursday, gradual warming trend Friday
through the weekend will bring well below normal temperatures
- Minor coastal flooding for bayshore locations along the San Francisco
Bay, San Pablo Bay, and Monterey Bay through Thursday morning
&&
.SHORT TERM...
Issued at 1245 AM PDT Tue Aug 11 2026
(Today and tonight)
Cooling trend continues today as upper-level shortwave troughing
deepens off the West Coast. The associated lift will deepen the
marine layer and bring a chance for drizzle to coastal areas. The
Timber Fire in Big Sur will continue to bring smoke and haze to the
Central Coast via light southwesterly transport winds from the
aforementioned troughing. Ample moisture and sufficient instability
will bring up to a 10% chance for elevated rain showers tomorrow.
The relatively greatest chances are across the Interior Mountains of
Monterey and San Benito Counties. The primary hazard would be
erratic/gusty outflow winds with dry low levels and DCAPE near 1000
J/kg. Minor coastal flooding is expected during the highest high
tide (evening/overnight) for bayshore locations along the San
Francisco Bay, San Pablo Bay, and Monterey Bay through Thursday
morning.
&&
.LONG TERM...
Issued at 1245 AM PDT Tue Aug 11 2026
(Wednesday through Monday)
A reinforcing trough Wednesday will bring widespread below normal
temperatures, deepen the marine layer further, and bring chances for
coastal drizzle through Thursday. It may also act as the trigger for
elevated rain showers/thunderstorms as it overlaps with an influx of
monsoonal/sub-tropical moisture and sufficient instability. The best
chances are across the Central Coast on Wednesday, more specifically
the southern and eastern portions. While confidence is low, this
would be a high-impact scenario with erratic/gusty outflow winds and
the potential for new fire starts. A gradual warming trend is
expected Friday through the weekend as upper-level ridging builds in
from the southeast; however, temperatures will still remain well
below normal.
&&
.AVIATION...
(06Z TAFS)
Issued at 935 PM PDT Mon Aug 10 2026
VFR across all terminals except Monterey Bay sites and KHAF. The
marine layer will continue to gradually increase through the
forecast period with increased coverage expected than what was
seen last night into this morning. Local offshore eddys will
complicate timing once again, especially for the Bay Area.
Vicinity of SFO...VFR with until after midnight with local
offshore eddys continuing to complicate exact timing of stratus.
The marine layer is expected to progress farther inland tonight.
KOAK may not see MVFR/IFR ceilings until the predawn hours with
KSFO potentially not being impacted despite more extensive
coverage of stratus due to the eddys.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR/IFR ceilings will persist through
the remainder of the overnight with a slight chance of continuing
through the entire forecast period as the marine layer gradually
increases through the day tomorrow with steady onshore flow,
breezy at times in the afternoon.
&&
.MARINE...
(Tonight through next Sunday)
Issued at 935 PM PDT Mon Aug 10 2026
Fresh to strong northwest winds will continue to produce rough
seas up to 13 feet across the northern outer waters through
Thursday. Long period southerly swell will gradually increase from
15 seconds through the middle of the week, up to 19 seconds by
Friday into Saturday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 2 AM PDT Thursday for CAZ006-506-
508-529-530.
PZ...Small Craft Advisory until 9 AM PDT Thursday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...JM
MARINE...JM
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Prepared by Boulder-Creek.com Weather at: Tue Aug 11 02:30:02 PDT 2026
From the National Weather Service
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