FXUS66 KMTR 122019
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
119 PM PDT Mon Oct 12 2026
...New SHORT TERM, LONG TERM, FIRE WEATHER...
.KEY MESSAGES...
Updated at 118 PM PDT Mon Oct 12 2026
- Cooler weather through tomorrow; warming trend and above normal
temperatures starting mid to late week
- Coastal flooding during high tides through midweek
- Hazardous beach conditions through this evening due to sneaker
waves, rip currents, and breaking waves
- Elevated fire weather conditions mid to late week for higher
elevations
&&
.SHORT TERM...
Issued at 118 PM PDT Mon Oct 12 2026
(This evening through Tuesday night)
An upper level trough dominates much of the West Coast's weather
this afternoon as the closed low sits over the PacNW and broad
troughing extends southward through California. To it's west, over
the eastern Pacific, high pressure is being observed. Satellite
imagery shows these too features quite well, with visible satellite
showing the base of the trough over Central and Southern California.
Most of our skies this afternoon remain clear; however, if you're in
the interior Central Coast region, you may see some small puffs of
cumulus clouds building over the ridges. So far there hasn't been
any measurable rain reported or observed, likely due to the dry air
in place and limited cloud growth.
Tonight, look for skies to clear and for another chilly fall night.
Temperatures should generally similar to or a few degrees higher
than last night. Tuesday's forecast will be similar to today, though
skies across the region should be mostly clear with high
temperatures being a few degrees warmer than today.
&&
.LONG TERM...
Issued at 118 PM PDT Mon Oct 12 2026
(Wednesday through next Sunday)
An upper level high pressure system over the eastern Pacific will
continue to build and expand eastward towards the West Coast. This
will help push the upper level trough out of the region late Tuesday
into Wednesday. During this time frame we will see a period of
offshore flow during the overnight hours. As the high continues to
build and the low moves east, each night will bring a renewed chance
of these offshore winds. Especially late in the week, as the upper
level trough elongates and then splits. When this occurs, the trough
situates over the Desert Southwest and around southern California.
Ridging remains over the northern half of the state which should lead
to an increase of offshore flow and our warming trend. Ensembles and
models then show signals of quasi-zonal flow and weak ridging for
the weekend. Temperatures should decrease in response to the pattern
change. For fire weather concerns, please see the fire weather
discussion below.
&&
.AVIATION...
(18Z TAFS)
Issued at 1030 AM PDT Mon Oct 12 2026
VFR conditions prevail through the period for most terminals due
to drier airmass. Clear skies tonight will lead to some
radiational cooling and possible fog (30-40%) for KSTS.
Vicinity of SFO...VFR. Diurnal wind pattern.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Diurnal wind pattern.
&&
.MARINE...
(Today through Saturday)
Issued at 1030 AM PDT Mon Oct 12 2026
Improving conditions over the coastal waters today as winds
continue to ease and overall seas state relaxes. However, fresh to
strong breezes and elevated swell will bring hazardous conditions
to smaller crafter over the outer waters.
&&
.FIRE WEATHER...
Issued at 118 PM PDT Mon Oct 12 2026
There will be a few bursts of offshore winds this week, generally
during the overnight hours. The first burst looks to occur tonight,
particularly highlight the interior North Bay Mountains, where we
could see gusts range from 20-35 mph, perhaps even up to 40 mph for
the exposed ridges and the higher elevations. After that, the next
area of concern we are monitoring is Wednesday night into Thursday
morning, where the pressure gradient should be a bit more tight due
to upper level wind patterns. Majority of the area should see
offshore flow, in the north to northeast component , with gusts
closer to 25-35 mph, locally higher perhaps up to 45 mph for exposed
ridges, gaps, and passes. Warm and dry weather will be on tap as
well, which will lead to an elevated threat for the higher terrain
areas. Another round of offshore winds is expected Thursday night
into Friday, but appears to be weaker than the previous two.
&&
.BEACHES...
Issued at 1031 AM PDT Mon Oct 12 2026
Compare to the last few days conditions along the coast are
gradually improving as longer period swell trains are decreasing.
However, buoy reports Monday morning continue to advertise
moderate to longer period swells (albeit smaller heights)
entering the coastal waters. As such, elevated surf zone
conditions lingering. Additionally, moderate period west-northwest
swell will arrive Monday afternoon lingering into Monday evening.
As such, Beach Hazard Statement remains in effect through this
evening. The large tidal swings will also result in coastal
erosion as water and waves are brought farther up the beach than
normal, especially during high tide. Remain off jetties, piers,
rocks, and other waterside infrastructure as waves can sweep
across the shoreline without warning, pulling people into the sea.
Never turn your back on the ocean!
MM
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 10 PM PDT this evening for CAZ006-
505-509-529-530.
Coastal Flood Advisory until 3 PM PDT Tuesday for CAZ006-508-529-
530.
Coastal Flood Advisory until 4 PM PDT Wednesday for CAZ506.
PZ...Small Craft Advisory until 3 AM PDT Tuesday for Pt Arena to Pt
Reyes 10-60 NM.
Small Craft Advisory until 3 PM PDT this afternoon for Pigeon Pt
to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...KR
LONG TERM....KR
AVIATION...MM
MARINE...MM
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Prepared by Boulder-Creek.com Weather at: Mon Oct 12 14:30:02 PDT 2026
From the National Weather Service
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