FXUS66 KMTR 111122
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
422 AM PDT Tue Aug 11 2026

...New AVIATION, MARINE...

.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...
(12Z TAFS)
Issued at 422 AM PDT Tue Aug 11 2026

Satellite shows stratus and fog /MVFR-IFR-LIFR/ developing and 
moving inland on onshore winds; winds supported by 1.8 mb SFO-SAC
pressure gradient. Otherwise it's VFR. The marine layer depth 
remains approximately 1300 to 1800 feet. Stratus and fog will mix 
out by late morning with VFR prevailing through the afternoon. 
Stratus, fog and patchy light drizzle /MVFR-IFR-LIFR/ develop and 
move inland tonight and Wednesday morning.

Vicinity of SFO...Stratus /MVFR/ developing this morning, it may
temporarily lower to IFR. VFR is forecast to return 18z today. West
to northwest wind 5 to 15 knots except 15 to 25 knots in the 
afternoon and evening. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus and fog /IFR-LIFR/ will mix out 
to VFR late morning to early afternoon with VFR continuing through
the afternoon. Stratus, fog and patchy light drizzle /IFR-LIFR/ 
develop and move inland tonight and Wednesday morning. West to 
northwest winds 5 to 15 knots.

&&

.MARINE...
(Today through Sunday)
Issued at 404 AM PDT Tue Aug 11 2026

Fresh to strong northwest winds will continue to produce rough
seas 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 17 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...Canepa
MARINE...Canepa

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Prepared by Boulder-Creek.com Weather at: Tue Aug 11 04:30:03 PDT 2026