FXUS66 KMTR 291201
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
501 AM PDT Tue Sep 29 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 135 AM PDT Tue Sep 29 2026

 - Elevated fire weather conditions across the higher terrain
   through Wednesday

 - Areas of moderate HeatRisk across the interior Wednesday
   through Monday

 - Minor coastal flooding for bayshore locations along the San Francisco,
   San Pablo, and Monterey Bays Monday through Thursday

&&

.SHORT TERM...
Issued at 135 AM PDT Tue Sep 29 2026
(Today and Wednesday)

The warming and drying trend kicks off today as upper-level ridging 
noses in from the Eastern Pacific Ocean behind the departing upper-
level low. This pattern will tighten and support a 
northerly/offshore pressure gradient that will bring elevated fire 
weather conditions to the higher terrain through Wednesday. 
Northerly/Offshore flow will be strongest overnight and in the 
higher terrain with speeds of 15-25 mph and gusts up to 35 mph. 
Sensible weather wise, temperatures will be near to 10 degrees above 
normal with areas of moderate HeatRisk. If the marine layer is able 
to survive, expect it to remain confined to the immediate coast and 
result in reduced visibility. Minor coastal flooding will continue 
during the highest high tide through Thursday for bayshore locations 
along the San Francisco Bay, San Pablo Bay, and Monterey Bay.

&&

.LONG TERM...
Issued at 135 AM PDT Tue Sep 29 2026
(Thursday through Monday)

Global ensemble clusters are in relatively good agreement that 
anomalously high heights will persist through Monday. The heat peaks 
over the weekend as upper-level longwave ridging moves in from the 
Eastern Pacific Ocean. Still, temperatures will remain 10 to 15 
degrees above normal with moderate HeatRisk away from the compressed 
marine layer at the coast. No records are in jeopardy.

&&

.AVIATION...
(12Z TAFS)
Issued at 501 AM PDT Tue Sep 29 2026

Satellite shows mainly clear skies across the region, with stratus 
being confined along the Central Coast and in the Salinas Valley. 
As a result, VFR conditions will prevail over much of the TAF cycle. 
Some models try to hint at stratus development along the coast 
towards 12Z Wed. Confidence was to low to hint at it in any of the 
coastal TAF sites. 


Vicinity of SFO...Clear skies and VFR conditions will prevail around 
SFO today. Onshore winds should pick up this afternoon and into the 
evening where we could see gusts up to 20-23kt. Winds begin to ease 
after sunset, falling to less than 10kt shortly around or after 
sunset. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...This is one of the few areas the marine 
layer holds its influence still, as stratus formed and has slinked 
into the Salinas Valley. IFR cigs have come with it, along with 
brief reductions in visibility. With the marine layer being 
compressed to around 500ft, this should erode within a couple of 
hours of sunrise. VFR conditions will then prevail, with the stratus 
trying to make a return again tonight. Models show a similar onset 
time, sometime between 7-10Z.

&&

.MARINE...
(Today through Sunday)
Issued at 253 AM PDT Tue Sep 29 2026

Hazardous conditions over the coastal waters are expected due to
strong to very strong northerly breezes. Frequent gale force gusts
are  expected across the northern waters through Wednesday
morning.  Conditions will begin to improve Wednesday night as
northerly  breezes diminish to become gentle to moderate, with
locally  hazardous conditions across the northern outer waters
likely to  continue. Rough to very rough seas through Wednesday
will subside  to become moderate to rough.

&&

.FIRE WEATHER...
Issued at 515 AM PDT Mon Sep 28 2026

The marine layer persists this morning, around 1500-2000ft, but
should gradually compress to around 500ft throughout the day.
Today will be coolest day of the week, though it is also the start
of a warming trend. Offshore flow gradually works its way into the
region today, which will lead to breezy winds each morning from through
Wednesday. The strongest winds are expected on Tuesday morning in
the interior mountains of the North and East Bays, where wind 
gusts could reach 30-35 mph. These offshore winds should 
contribute to poor overnight humidity recoveries, with overnight 
relative humidities as low as 20-40% above the marine layer.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 5 PM PDT Thursday for CAZ006-506-
     508-529-530.

PZ...Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena 
     to Pt Reyes 0-10 nm.

     Gale Warning from 3 PM this afternoon to 9 PM PDT this evening 
     for Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 3 AM PDT 
     Wednesday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes to 
     Pigeon Pt 0-10 nm.

     Small Craft Advisory until 3 AM PDT Wednesday for Pt Pinos to Pt 
     Piedras Blancas 0-10 nm.

     Gale Warning until 9 AM PDT Wednesday for Pt Arena to Pt Reyes 
     10-60 NM.

     Small Craft Advisory until 3 PM PDT Wednesday for Pigeon Pt to 
     Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...KR
MARINE...KR

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Prepared by Boulder-Creek.com Weather at: Tue Sep 29 08:30:03 PDT 2026