FXUS66 KMTR 250837
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
137 AM PDT Mon May 25 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 135 AM PDT Mon May 25 2026

 - Below normal temperatures with coastal and higher terrain
   drizzle today

 - Upper-level troughing will bring strong northerly winds Tuesday
   and kickoff a gradual warming and drying trend Wednesday

&&

.SHORT TERM...
Issued at 135 AM PDT Mon May 25 2026
(Today and tonight)

The unofficial start of summer sure won't feel like it. Temperatures 
will remain well below normal with the help of a 2,500 feet deep 
marine layer. Stratus will retreat to the coast by late morning with 
a mix of sun and clouds expected for the interior tomorrow 
afternoon. Surface troughing and an approaching cold front will even 
allow for some precipitation - the coast and higher terrain will 
have the greatest chances with the help of orographic lift. It'll 
likely be more in the way of drizzle than light rain; nonetheless, a 
few hundredths is expected at most.

&&

.LONG TERM...
Issued at 135 AM PDT Mon May 25 2026
(Tuesday through Sunday)

Upper-level troughing arrives tomorrow, making it the coolest day of 
the week. Of more impact will be the northerly (drying) winds. Wind 
gusts of 30-40 mph are expected along the coast, across ridgelines, 
and through gaps and passes. Widespread hazardous conditions for 
small craft will result. As the trough digs into the state 
Wednesday, it is expected to become a cutoff low that remains near-
stationary through Thursday. This will support a gradual warming and 
drying trend as northerly winds remain in place. Of more interest 
and potential impact is the thunderstorm threat. Chances are low 
(10% or less) with the relatively best chances for the far interior. 
The three necessary ingredients of lift, instability, and moisture 
will be present. Conditionally unstable lapse rates (~7 degrees 
C/km) will yield low CAPE (~500 J/kg); with most of it presenting as 
surface based CAPE, sufficient daytime heating will be needed. The 
limiting factor will likely be moisture with PWAT values near 
average. New wildfire starts will be a potential hazard due to fuels 
being about a month ahead of schedule. The low is expected to fill 
and become an open wave by Friday, leaving the area under zonal flow 
with onshore flow over the weekend.

&&

.AVIATION...
(06Z TAFS)
Issued at 919 PM PDT Sun May 24 2026

Stratus has begun to build along the coast and move farther inland
over the North Bay. Expect widespread MVFR cigs at all terminals
soon after midnight with a robust marine layer and steady onshore
flow. Monday lifting of MVFR cigs to VFR will coincide with a
notable increase of onshore winds especially for the Bay Area and
South Bay terminals out ahead of a developing cold front. Expect
breezy to gusty winds Monday afternoon and evening. 

Vicinity of SFO...VFR is expected until midnight with MVFR cigs
through the overnight hours into early afternoon, then VFR with 
increasing onshore winds, gusty at times through Monday evening.
Winds out ahead of the advancing cold front offshore are not
expected to reach AWW thresholds.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR cigs will persist overnight with
higher confidence that KMRY will persist into the early afternoon,
when onshore winds increase becoming breezy through the afternoon
through sunset out ahead of the advancing cold front to the north
with lesser influence this far south.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 919 PM PDT Sun May 24 2026

Light west/southwest breezes continue tonight through Monday, then
begin to strengthen Monday night into gusty northwest winds for
Tuesday into early Wednesday. Expect building rough seas on
Tuesday that persist through the end of the work week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM to 9 PM PDT Tuesday for Mry Bay-
     Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 
     NM.

     Small Craft Advisory from 3 AM to 9 PM PDT Tuesday for Pt Arena 
     to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos 
     to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...JM
MARINE...JM

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Prepared by Boulder-Creek.com Weather at: Mon May 25 02:30:02 PDT 2026