FXUS66 KMTR 222347
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
447 PM PDT Tue Sep 22 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1232 PM PDT Tue Sep 22 2026

 - Warming trend continues through Thursday

 - Cooler conditions Friday into the weekend

&&

.SHORT TERM...
Issued at 1232 PM PDT Tue Sep 22 2026
(This evening through Wednesday night)

An upper level trough is moving across Nevada this afternoon and 
will continue to shift into the Great Basin on Wednesday. As such, 
temperatures this afternoon are forecast to warm into the 60s near 
the coast, upper 60s to low 70s around the bayshore, and mid 70s to 
mid 80s across the interior with mostly sunny sky conditions across 
the interior. Breezy onshore flow will develop in the afternoon and 
evening hours with gusts of 20 to 30 mph near the coast, in the 
favored gaps and passes, and down the Salinas Valley. 

As the marine layer gradually compresses to around 1,500 feet 
tonight, we are expecting less of an inland intrusion of stratus. As 
such, temperatures are expected to cool into the 50s for much of the 
region overnight. More of a zonal flow is forecast on Wednesday 
which will lead to a warming trend. Temperatures Wednesday afternoon 
are forecast to reach into the upper 60s to mid 70s near the coast, 
upper 70s to mid 80s around the bayshore, and mid 80s to low 90s 
across the interior. The warmest interior portions of the Central 
Coast look to warm into low-to-upper 90s. This will result in 
pockets of moderate HeatRisk across the interior. As a result, drier 
conditions are forecast in elevations above the marine influences.

Tomorrow night, look for again less inland extent of stratus and the 
warming trend to continue. Overnight temperatures are forecast to be 
in the mid 50s near the coast to lower 60s across the interior. 
However, the warming air mass aloft will result in the higher 
terrain only cooling into the 70s. 

&&

.LONG TERM...
Issued at 1232 PM PDT Tue Sep 22 2026
(Thursday through next Monday)

Thursday looks to be the warmest across the interior with similar 
temperatures to Wednesday elsewhere. On Friday, a developing trough 
off of the West Coast will return resulting in a cooling trend and  
deepening of the marine layer. The coolest conditions are expected
Saturday and Sunday as a reinforcing trough deepens off of the 
California coast with temperatures up to 10-15 deg F below 
seasonal averages. Temperatures appear to rebound closer to normal
for this time of year early next week as the trough flattens and 
the 500 mb height clusters point to a building ridge over the 
western United States. 

&&

.AVIATION...
(00Z TAFS)
Issued at 412 PM PDT Tue Sep 22 2026

VFR conditions are expected to prevail through the forecast period
for majority of the terminals with low confidence of MVFR/IFR 
ceilings possible for KAPC and KOAK in the overnight hours as the
marine layer compresses somewhat and becomes less organized than 
the previous couple of nights.

Vicinity of SFO...VFR is expected to prevail for KSFO with the
marine layer getting compressed and less organized. There is a
chance of MVFR/IFR ceilings at KOAK developing after midnight and
persisting into the mid-morning with relatively light but steady 
fetch of onshore flow through Golden Gate.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR/IFR ceilings have settled. Normal 
diurnal trend of IFR/LIFR ceilings with VFR expected by early 
afternoon Wednesday, maybe sooner if less organized marine layer 
manifests this far south. Otherwise, VFR for Wednesday afternoon 
through the remainder of the TAF period.

&&

.MARINE...
(Tonight through next Sunday)
Issued at 412 PM PDT Tue Sep 22 2026

Northwest moderate to fresh breezes with strong gusts steadily
diminish across the southern coastal waters while remaining
elevated  to the north on Wednesday. Rough northwest seas continue
into  Wednesday before gradually subsiding to moderate for a brief
period  on Thursday. By Friday, northwest winds increase again
with building  rough seas.

&&

.FIRE WEATHER...
Issued at 434 AM PDT Tue Sep 22 2026

Solid marine layer coverage along the coast and Salinas Valley
overnight. Sounding and profilers put the depth of the marine
layer around the 2,000-2,500 foot range. Definitely some
compression on the marine layer leading to drizzlefest around the
area. Seeing some reduced vsby too, which may lead to patchy fog
early this morning for crews departing ICP for Timber/Plaskett.
Above the marine layer moderate to excellent humidity recovery 
for the most part with the driest conditions above 3,000 feet. 
Otherwise, still valid for a warming and drying trend kicking off 
Tuesday with temperatures up to 10 degrees above normal and areas 
of moderate HeatRisk Wednesday and Thursday. The marine layer will
compress below 1,000 feet during this warm-up with nocturnal 
drying expected above it.

MM

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 5 AM PDT Wednesday for Pigeon Pt to 
     Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt 
     to Pt Pinos 0-10 nm.

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

     Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...JM
MARINE...Navarrete

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 Sep 22 20:30:03 PDT 2026