FXUS66 KMTR 160603
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1103 PM PDT Sat Aug 15 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 1102 PM PDT Sat Aug 15 2026

 - Gradual warming and drying trend into next week

&&

.SHORT TERM...
Issued at 1102 PM PDT Sat Aug 15 2026
(Tonight through Monday)

Heights will begin to rise Sunday as upper-level ridging nudges in 
from the east. We're already seeing an effect of this with a 
compressing marine layer bringing lower clouds and less inland 
extent. Sunday morning will offer another chance for drizzle along 
the coast and in the higher terrain. Temperatures will remain below 
normal under the marine layer influence with inland and higher 
elevation locations warming to near normal. Diurnal winds will keep 
smoke from the Timber Fire out to sea with downsloping (easterly) 
winds in the morning and onshore (northwesterly) winds in the 
afternoon.

&&

.LONG TERM...
Issued at 1102 PM PDT Sat Aug 15 2026
(Monday night through next Saturday)

Global ensemble clusters are in agreement that upper-level ridging 
will nose, and ultimately build, into the Intermountain West through 
Thursday. Sensible weather wise, locations inland from and above the 
compressed marine layer (~1,000 feet) will moderate to near to 
slightly above normal. Along the coast, temperatures will remain 
below normal with evening/morning clouds. To put this event into 
context, 850 mb temperatures will increase to the 75th-90th 
percentile; even so, no records are forecast. Even with the warming 
and drying trend, heat and fire weather impacts are expected to 
remain minor. Fire weather wise, seasonably elevated conditions with 
rapid rates of spread on any wind-and-terrain aligned starts in 
receptive vegetation will be possible in higher terrain, 
specifically with the diurnal sea breeze in the
afternoons/evenings.

&&

.AVIATION...
(06Z TAFS)
Issued at 1000 PM PDT Sat Aug 15 2026

Mostly IFR-LIFR stratus is expanding through the Petaluma Gap, into 
the SF Bay region, and across the southern Monterey Bay. Stratus is 
expected to continue developing through the night with clearing 
expected in the late morning hours on Sunday. Lingering onshore 
breezes will diminish to a light wind overnight. Moderate onshore 
winds will resume Sunday afternoon and evening, with a compressing 
marine layer resulting in lower ceilings and limited development 
inland, especially in the interior East Bay, as the marine layer 
clouds return Sunday night. 

Vicinity of SFO... IFR stratus through the night will clear out late 
Sunday morning with moderate and potentially gusty west-northwest 
winds resuming in the afternoon. Low confidence in the timing of IFR-
LIFR stratus return Sunday evening and overnight with high 
resolution model output showing the stratus deck developing right at 
the edge of the terminal. 

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... MVFR-IFR stratus with light winds 
continues overnight. Stratus will mix out late Sunday morning and 
early afternoon (moderate confidence at MRY, high confidence at 
SNS), with breezy northwest winds expected in the afternoon and 
evening hours. Expect stratus to return rather early Sunday evening 
with IFR-LIFR ceilings expected.

&&

.MARINE...
(Tonight through next Friday)
Issued at 1000 PM PDT Sat Aug 15 2026

A gentle to moderate northwesterly breeze persists through Sunday
with localized fresh gusts possible across the interior waters. A
long period southerly swell of about 15 to 17 seconds will linger
through Sunday. Winds increase to fresh to strong beginning
Monday and remain elevated through the end of the forecast period.
Seas of around 4 to 5 feet will build to 7 to 9 feet mid week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...DialH
MARINE...DialH

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Prepared by Boulder-Creek.com Weather at: Sun Aug 16 04:30:03 PDT 2026