FXUS66 KMTR 131718
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
918 AM PST Tue Jan 13 2026
...New UPDATE, MARINE...
.KEY MESSAGES...
Updated at 125 AM PST Tue Jan 13 2026
- Chilly conditions this morning give way to warm daytime
temperatures through the week with light offshore winds
- Elevated risk of sneaker waves through Thursday
- Pattern change possible next week
&&
.UPDATE...
Issued at 858 AM PST Tue Jan 13 2026
Tranquil conditions continue for today, with largely mostly sunny
skies. A few high clouds may attempt to skirt around the eastern
periphery of our H5 ridge and graze far interior portions of the
East Bay and Central Coast. Total column moisture continues to
diminish with the 12Z OAK RAOB sampling a PWAT of near 0.25" this
morning. This is around 0.15" lower than 24 hours ago. This
should equate to a steeper diurnal temperature curve and thus
warmer conditions compared to Monday (yesterday). The current
forecast for today (Tuesday) seems reasonable for MaxT with
widespread 60s and low 70s. Believe it or not, "Minor" HeatRisk is
advertised across parts of the Central Coast. In fact, a handful
of the valleys across the Central Coast, could see (around a
15-20% chance) temperatures climb into the mid 70s, especially
across the SC Mountains. All in all, not anticipating widespread
heat impacts and the real "impactful" weather element will be a
continued risk for hazardous beach conditions through the end of
the week, possibly longer. Be sure to check the latest beach
forecast before heading out.
&&
.SHORT TERM...
Issued at 125 AM PST Tue Jan 13 2026
(Today and tonight)
Fog has developed tonight in parts of Sonoma County, namely the
Russian River Valley and the northern Santa Rosa Plain. It's a
little hard to pick out in the satellite imagery, but it is being
shown on local webcams and the observations from Sonoma County
Airport. Visibilities should improve after sunrise this morning.
Otherwise, skies remain clear across the Bay Area and Central Coast
with light winds enhancing the chances for radiational cooling
across the region. A Cold Weather Advisory is in effect across the
interior North Bay and East Bay valleys and the interior Central
Coast including the southern Salinas Valley through 9 AM as the lows
dip into the lower to middle 30s across the area. Elsewhere, low
temperatures reach the upper 30s to middle 40s in the lower
elevations and upper 40s to lower 50s in the higher elevations.
No significant weather concerns today as an upper level ridge
continues to dominate the weather pattern across the western United
States. Light offshore flow is expected to develop with wind gusts
topping out around the 15 to 20 mph range, and even then only during
the morning across favored regions near the Golden Gate and the
Pajaro Valley. High temperatures range from the upper 50s to lower
60s in the San Francisco area and the East Bay, and the middle 60s
to the lower 70s in the inland valleys.
&&
.LONG TERM...
Issued at 125 AM PST Tue Jan 13 2026
(Wednesday through Monday)
For the weekly forecast, it's wash, rinse, repeat. High pressure
stalls over the western United States, resulting in an extended
period of seasonally warm daytime highs, mild nighttime lows, and
light offshore winds. To give an idea of the regional warmth, high
temperatures through the upcoming weekend are around 5 degrees above
the seasonal average in downtown San Francisco, and around 8 to 15
degrees above the seasonal average across the rest of the Bay Area
and Central Coast.
Towards the early part of next week, just beyond the end of the 7-
day outlook, the upper level ridge begins to erode, allowing
temperatures to cool. Beyond that, the level of uncertainty over the
evolution of the weather pattern shoots upward. The previous
forecaster noted the split between those models that break down the
upper ridge more quickly into onshore flow and those that kept the
ridging in place a little longer. Looking at the latest ensemble
model cluster guidance, this still appears to be the case. By the
21st, the ensemble model clusters are split roughly half-to-half
between those with a more pronounced trough across the West Coast
and those that keep more zonal flow or even a residual ridge in
place. All together, it appears that a period of more active weather
may be in store as we head towards the end of the month.
&&
.AVIATION...
(12Z TAFS)
Issued at 333 AM PST Tue Jan 13 2026
Currently VFR at all terminals with the exception of STS. Low
visibility is expected through mid-morning at STS before giving
way to VFR. Winds will generally be light and offshore, with the
exception of moderate drainage winds down the Salinas Valley into
SNS during the overnight periods. Moderate to high confidence on
fog returning to STS tonight with VFR elsewhere.
Vicinity of SFO...Currently VFR and calm at the terminal.
Southeasterly winds this morning will back to become northeasterly
this afternoon. High confidence on sustained winds remaining below
10 knots through the TAF period.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Currently VFR with drainage flow at both
terminals. Winds will back to become northerly this afternoon with
drainage winds returning tonight.
&&
.MARINE...
(Today through Sunday)
Issued at 858 AM PST Tue Jan 13 2026
Gentle to moderate easterly to northeasterly winds continue today,
before northerly winds return on Wednesday. Offshore winds return
Thursday and Saturday before northerlies return over the weekend.
Moderate seas will prevail through the week with the exception of
the northwestern portion of the waters where rough seas will
briefly build in Wednesday into Thursday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
UPDATE...Bain
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...KR
MARINE...KR
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea
Prepared by Boulder-Creek.com Weather at: Tue Jan 13 10:30:02 PST 2026
From the National Weather Service
|