FXUS66 KMTR 151821
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1121 AM PDT Wed Apr 15 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1214 AM PDT Wed Apr 15 2026

 - Near normal temperatures continue today and Thursday before
   temperatures warm Friday into the weekend

 - Periods of gusty offshore winds, especially at higher
   elevations, Wednesday afternoon through early Friday morning
 
 - Increasing confidence for widespread beneficial rain beginning Sunday
   into the beginning of next week

&&

.SHORT TERM...
Issued at 1214 AM PDT Wed Apr 15 2026
(Today and tonight)

A weak fetch of onshore flow at the surface is struggling to 
maintain patches of low stratus along the SF Peninsula and the 
Salinas Valley late tonight. Progressive ridging aloft has resulted 
in very dry air in the mid/upper levels, that will persist into the 
early afternoon. A sharpening trough to our north will reach the 
North Bay tonight behind the exiting ridge, with a weak associated 
moisture gradient out ahead. However, increasing low and mid-level 
onshore flow will result in a moderate increase in cloud cover this 
afternoon. Breezy west winds out ahead of the dry surface boundary 
will eventually become northerly overnight as the upper trough 
pivots east and south. Temperatures today will be similar to 
yesterday, maybe a few degrees warmer inland where less cloud cover 
is expected. Temperatures tonight will still be on the cool side 
across the North Bay and higher elevations across the East Bay Hills 
with weak cool advection behind the dry surface boundary late 
tonight.

&&

.LONG TERM...
Issued at 1214 AM PDT Wed Apr 15 2026
(Thursday through Tuesday)

Gusty offshore flow will gradually spread south across our area 
after sunrise Thursday. The strongest winds will be at higher 
elevations, especially in the North Bay and East Bay Hills, but not 
expected to exceed 40mph. Temperatures on Thursday will be similar 
to Wednesday, right around normal in the 60s to low 70s. 
Temperatures overnight Thursday into Friday will be chilly once 
again with cooler air aloft lingering behind the exiting trough and 
surface wind fields easing simultaneously under clear skies leading 
to efficient radiational cooling. Thursday night should be an 
excellent night for star gazing. Progressive, yet high amplitude 
ridging bumps temperatures up Friday and Saturday, before the next 
trough arrives from the Pacific Northwest on Sunday. Consensus 
diverged in deterministic guidance from this time last night, thus 
confidence in timing, location and intensity of rainfall is still 
low. However, it still looks most of our area will see at least some 
light rain Sunday through Tuesday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1059 AM PDT Wed Apr 15 2026

AM clouds/fog have given way to mostly VFR for 18Z tafs. Some
coastal strato-cu will occasionally impacts HAF and MRY. A weak
boundary will sweep through this evening/early tonight bring a 
return of brief MVFR CIGS from approx 03Z-08Z depending on 
terminal. Behind the boundary offshore flow and drier air rush in 
kicking LL moisture out with VFR returning. Moderate wind speeds 
are expected at all TAF sites mentioned above throughout the day 
and night with some experiencing strong gusts. Winds are expected 
to decrease slightly by tomorrow morning before increasing again.


Vicinity of SFO...VFR with a few CU hugging the hills to the 
west. Probabilistic guidance brings frontal CIGS to the San Bruno 
gap close to 03Z and then over the terminal by 05-06Z. Once the 
boundary goes through drier air erodes MVFR cigs by 09-10Z

SFO Bridge Approach...CIGS arrival and clear tonight will be 30-60
min after terminal.

Monterey Bay Terminals... Around 03-04z tonight, lower CIGs will  
make their way through MRY, and SNS resulting in MVFR conditions. 
These low clouds will eventually dissipate out by early to mid-
morning tomorrow and conditions will shift back to VFR, except at 
MRY where they will stick around through the end of the TAF 
period.

&&

.MARINE...
(Today through Monday)
Issued at 353 AM PDT Wed Apr 15 2026

Fresh northwest breezes and moderate seas will continue over the
coastal waters through today. A mostly dry cold front will push
through tonight followed by gusty northwesterly winds Thursday.
These winds will build rough seas of 10-12 feet across the exposed
coastal waters. Winds will ease back to moderate northwest breezes
Friday through Saturday, allowing seas to gradually subside.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PDT Thursday for Mry Bay.

     Small Craft Advisory from 9 PM this evening to 9 PM PDT Thursday 
     for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 
     nm.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PDT 
     Thursday for Pt Reyes to Pigeon Pt 0-10 nm.

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

     Small Craft Advisory from 9 PM this evening to 3 AM PDT Friday 
     for Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory from 3 AM Thursday to 3 AM PDT Friday for 
     Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...MM/AN
MARINE...Canepa

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Prepared by Boulder-Creek.com Weather at: Wed Apr 15 12:30:03 PDT 2026