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 02:30:02 PDT 2026
From the National Weather Service
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