FXUS66 KMTR 250352
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
852 PM PDT Thu Sep 24 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 920 AM PDT Thu Sep 24 2026
- Warming trend persists today bringing pockets of moderate
HeatRisk across parts of the Bay Area and Central Coast.
- Cooler conditions arrive Friday into the weekend.
- Near seasonal temperatures early next week.
&&
.SHORT TERM...Issued at 358 PM PDT Thu Sep 24 2026
(This evening through Friday night)
The lack of marine layer development last night (aka our natural air
conditioning) allowed temperatures to reach well into the mid 80s to
90s across the interior mountains and valleys of the
North/East/South Bay and Bay shoreline, with temperatures closer to
the mid 90s across the interior Central Coast. The Pacific coastline
remains under the marine influence, therefore temperatures were
observed in the mid 60s to 70s.
Overnight, the anticipated cold front pushes through our forecast
area. This will bring some relief Friday morning with a thick post-
frontal stratus deck and a prominent onshore push of cool, albeit
dry, air. Despite the frontal passage, dry air aloft will mix out
the majority of low clouds allowing high clouds to dominate the
skies through the afternoon into the evening. Because the main core
of the 500 mb trough remains far north of our area, no significant
impacts are expected with this system. The main impact associated
with the post-frontal environment are strong gusts around 20 to 25
mph along the coast into the SF Peninsula.
&&
.LONG TERM...
Issued at 358 PM PDT Thu Sep 24 2026
(Saturday through next Wednesday)
This weekend, the troughing pattern persists, thereby allowing for
cold air advection to gradually fill into the region. There is
potential for the 500 mb trough to dig more southward over the Bay
Area and Central Coast Sunday into Monday, eventually becoming a cut-
off low southeast of our forecast area. In response, building high
pressure behind the trough may induce a push of weak offshore flow
across the higher terrain in the North and East Bay, initiating
another warming period early next week.
&&
.AVIATION...
(06Z TAFS)
Issued at 850 PM PDT Thu Sep 24 2026
VFR is expected to prevail through the forecast period for a
majority of the terminals. Higher confidence in Monterey Bay sites
developing MVFR/IFR ceilings late in the overnight hours to near
sunrise, with lower confidence for the North Bay and Bay Area sites
around the same time.
Vicinity of SFO...VFR with gusty onshore winds persisting through a
majority of the forecast period. A slight chance of MVFR ceilings
developing around sunrise with low confidence in the extent and
timing due to a relatively weak marine layer that mostly confined
to the coast.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR with higher confidence in MVFR/IFR
ceilings developing late in the overnight hours to near sunrise
Friday morning, with VFR expected by mid-morning due to the weak
and compressed marine layer.
&&
.MARINE...
(Tonight through next Wednesday)
Issued at 850 PM PDT Thu Sep 24 2026
Expect fresh to strong northerly breezes to continue through the
weekend behind a cold front that pushes through overnight. Near
gale force winds are possible across Monterey Bay south to Big Sur
Sunday afternoon and evening. Tropical storm activity producing
long period southerly swell begins to increase for the beginning
of next week.
&&
.FIRE WEATHER...
Issued at 450 AM PDT Thu Sep 24 2026
Marine layer is pretty much non-existent overnight. That led much
less RH recovery across the district at both lower and higher
elevations. NGFS gave us a hit earlier in the night as the Timber
Fire had an northern perimeter flare up. Even FireGuard showed the
heat as well. Not completely surprised given temps in the 70s and
RH recovery around 30 pct near Timber. Otherwise, notes for today
will be another mild and dry day across the district. Hottest and
driest across the interior portions. Do expect an uptick with
winds late tonight and Friday as a dry front moves through. Cooler
and wetter for Friday and over the weekend.
MM
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt
Reyes 10-60 NM.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM to 9 PM PDT Friday for Mry Bay.
Small Craft Advisory from 9 AM Friday to 9 AM PDT Saturday for
Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-
Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 PM PDT Saturday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Small Craft Advisory from 9 AM Friday to 3 PM PDT Sunday for Pt
Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 9 AM Friday to 3 PM PDT Saturday for
Pigeon Pt to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...Navarrete
LONG TERM....Navarrete
AVIATION...JM
MARINE...JM
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Prepared by Boulder-Creek.com Weather at: Thu Sep 24 22:30:03 PDT 2026
From the National Weather Service
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