FXUS66 KMTR 132308
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
408 PM PDT Tue Oct 13 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 221 PM PDT Tue Oct 13 2026
- Warming trend will continue through the work week, with above
normal temperatures
- Coastal flooding during high tides through midweek
- Elevated fire weather conditions and offshore flow across the
higher elevations peaking mid to late week
&&
.SHORT TERM...
Issued at 320 PM PDT Tue Oct 13 2026
(This evening through Wednesday night)
Water vapor imagery shows the upper level low over the Great
Basin starting to move east this afternoon, with high pressure
remaining over the Pacific. As a result, Northern California
remains situated between the two, with dry northerly flow aloft.
Despite the cooler start to the day, temperatures have warmed
nicely today, with sunny skies prevailing. In fact, temperatures
are running 3 to 6 degrees warmer than this time yesterday for
most locations, with up to 10 degree warmer for North Bay areas,
thanks to some light offshore flow. These warmer conditions will
make for a pleasant evening across the region.
Expect one more cool fall like night tonight, as clear skies, dry
conditions, and light winds aid in the radiative cooling. Most
locations will fall into the 40s to lower 50s tonight, with fewer
spots dipping into the 30s. That said, we will have some light
offshore winds once again across the interior North Bay Mountains
tonight. With weak offshore gradients and marginal upper level
support (10-15 kts at 925 and 850 mbs), think gusts will mostly
stay around 30 mph tonight. Some of the favored ridges, gaps or
passes could be higher though.
Our warming trend will continue into Wednesday, as high pressure
rebuilds into the region. Expect daytime temperatures to increase
another 3 to 7 degrees tomorrow, with the greatest warming
occuring across the inland areas. Also expect another round of
offshore winds for Wednesday night to develop across the interior
North Bay Mountains. There is a little better support this
evening, as offshore gradients into to around 7 mbs, and 925 mb winds
increase to 15 to 25 kts. Therefore, expect gusty conditions to
develop once again across the favored exposed ridges, passes, and
gaps. Palmer
&&
.LONG TERM...
Issued at 320 PM PDT Tue Oct 13 2026
(Thursday through next Monday)
High pressure will continue to strength across the region, with
our warming trend continuing through Friday. Daytime temperatures
will warm a few degrees each day, with Friday likely being the
peak of this heat event. While the warmest spots will stay in the
90s this time around, we will see a Moderate Heat Risk for some of
our inland areas, thanks to the overnight temperatures will also
warming a bit each night. We are also expecting one last push of
offshore winds Thursday night into Friday. These push looks
stronger than the previous two nights, with ever so slightly
better upper level support. For now, think the winds will once
again be limited to the exposed ridges, gaps, and passes, with
gusts up to 40 mph possible. Some of the favored spots may see
higher gusts, but those stronger gusts will be isolated at best.
Our ridge will start to flatten this weekend, with Saturday being
the start of our cool down. It will still be warm through the
weekend across the inland areas, just not as warmer as Friday.
The flattening of the ridge over the weekend opens the door for a
trough to dig south from the Gulf of Alaska for early next week.
At this point in time, the ensembles are in very good agreement
with this trough digging along the West Coast, and bringing
another round of cooler air to the region. The uncertainty comes
with the strength and timing. For now, it does look strong enough
to be us some gusty onshore winds and our first decent chance of
widespread rain. While it doesn't look like much rain, there is a
10-30 percent chance of rain for Monday and Tuesday. Needless to
say, this will bear watching. Palmer
&&
.AVIATION...
(00Z TAFS)
Issued at 408 PM PDT Tue Oct 13 2026
Generally VFR conditions prevail through the TAF period, with some
high resolution models depicting patchy coastal stratus towards the
end of the TAF period. Gentle to moderate northwest to north flow
persists into the evening hours, with light winds overnight before
the onshore winds resume Wednesday afternoon
Vicinity of SFO... VFR at the terminal through the TAF period.
Gentle to moderate northwest flow will continue into the evening,
with light offshore flow developing overnight into Wednesday morning
before moderate northwest winds resume in the afternoon.
SFO Bridge Approach... Similar to SFO.
Monterey Bay Terminals... Moderate to high confidence of VFR through
the TAF period. Gentle to moderate northwest winds prevail through
the evening hours, with light drainage winds overnight before gentle
to moderate northwest winds resume Wednesday afternoon.
&&
.MARINE...
(Tonight through next Sunday)
Issued at 408 PM PDT Tue Oct 13 2026
Strong northwesterly gusts are expected nearshore from Pigeon
Point to Point Pinos and the Monterey Bay through this evening.
Otherwise, gentle to fresh northerly breezes will continue through
the remainder of the week with an improving seas state through
Wednesday. Long period southerly swell will also continue through
midweek with some gradual easing by the end of the week.
&&
.FIRE WEATHER...
Issued at 320 PM PDT Tue Oct 13 2026
Periods of gusty offshore winds will develop the overnight and
into the early morning hours the next several nights. At this
point in time, the upper level support is marginal at best, but it
is there. Therefore, expect primary gusts of 25 to 35 mph possible
across the interior North Bay Mountains. Some of the favored
exposed ridges, gaps, and passes could see some locally higher
gusts up to 40 mph. With each burst of offshore winds, overnight
humidity recoveries will become more poor, with widespread poor
to moderate recoveries possible. Therefore, elevated fire weather
conditions will be a concern the next several days. Remember, be one
less spark if you are needing to do outside work.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 4 PM PDT Wednesday for CAZ506.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay-
Pigeon Pt to Pt Pinos 0-10 nm.
&&
$$
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...DialH
MARINE...RGass
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Prepared by Boulder-Creek.com Weather at: Tue Oct 13 16:30:03 PDT 2026
From the National Weather Service
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