FXUS66 KMTR 171203
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
403 AM PST Sat Jan 17 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1205 AM PST Sat Jan 17 2026
- Dry weather, cool mornings, and warm afternoons continue
&&
.SHORT TERM...
Issued at 1205 AM PST Sat Jan 17 2026
(Today and tonight)
Conditions are similar to last night, with a few subtle changes.
First, the marine stratus has peeled off the coast. This is thanks
to robust offshore flow. The SFO-WMC gradient is -12.3 mb, quite a
bit stronger than most models have it analyzed. Mt. St. Helena is
reporting ENE winds gusting as high as 47 mph tonight. This and
several other mountain stations would actually be in Red Flag
Criteria if the annual grasses were cured. This offshore gradient
will weaken over the next 36 hours as both the strong surface high
over the Rockies and the trough over California weaken. The other
difference tonight is high clouds moving in from the south. These
will help moderate both the min and max temperature by a degree or
two and bring some color to the sunrise and sunset today. Otherwise
it will feel very similar to yesterday.
&&
.LONG TERM...
Issued at 1205 AM PST Sat Jan 17 2026
(Sunday through Friday)
Sunday will be a rinse and repeat of Saturday. Expect a chilly
morning, warm afternoon and some high clouds through the day. This
pattern will stick around as the strong ridging that extends all the
way to the jet stream will continue through the week. There is a
chance for a short wave trough at 500 mb to bring some very light
rain Thu-Fri, but it's looking more and more like that will just
be a cloud maker. That little trough is important though. It's
the first domino to fall in the gradual pattern change. The 500 mb
flow will likely become more zonal by next weekend. There's
significant disagreement in the ensemble clusters after next
weekend, but some solutions bring a legitimate troughing pattern
and possible wet weather back for the last week of January. The
00Z ECMWF ensemble IQR has between 1.0-2.5" of rain from the 27th
to the 31st at SFO.
&&
.AVIATION...
(12Z TAFS)
Issued at 403 AM PST Sat Jan 17 2026
VFR continues for most TAF sites through the TAF period. The
exceptions will be STS and APC which will see fog this morning and
again tonight. Winds will mostly say light through the TAF period
with directions being mostly variable, although some localized
effects will determine the wind directions at a few of the TAF
sites.
Vicinity of SFO...VFR through the TAF period. Expect mostly light
and variable winds through much of the day before winds turn
northeasterly in the late afternoon, but become variable again into
the night.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR through the TAF period. East to
southeast winds last through into the afternoon before winds more
variable. Winds turn easterly and southeasterly again into the night.
&&
.MARINE...
(Today through Thursday)
Issued at 403 AM PST Sat Jan 17 2026
Expect moderate to breezy winds across the San Pablo Bay, the
delta, and through the Golden Gate through the weekend while
light northeasterly to northerly winds persist across the rest of
the waters. Light seas continue into early next week before the
next round of long period swell arrives and brings light to
moderate seas in the mid week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Murdock
MARINE...Murdock
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Prepared by Boulder-Creek.com Weather at: Sat Jan 17 06:30:03 PST 2026
From the National Weather Service
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