Technical NOAA Weather Discussion

FXUS66 KMTR 291759
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1059 AM PDT Wed Apr 29 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1257 AM PDT Wed Apr 29 2026

 - Overnight and early morning stratus returns to the forecast

 - Warming and drying trend continues into the late week for 
   areas away from the coast

 - Cooler conditions return this weekend with a chance of drizzle
   and/or light rain into early next week 

&&

.SHORT TERM...
Issued at 1257 AM PDT Wed Apr 29 2026
(Today and tonight)

Coastal Stratus is building along the SF Peninsula and around Point 
Reyes. This cloud cover will be spotty along the coast, will build 
further into the night, affecting the bays. This is a good indicator 
that the marine layer is becoming more stable, and looks to stay 
intact despite the ridging pattern to the north. A big player in 
retaining the marine layer is the cut off low to the south west 
which will prevent too much of a climb in pressure and keep the 
marine zones and immediate coast on the breezier side.

While the marine influence will keep coastal and slightly inland 
temperatures fairly stable over the next few days, areas further 
inland will continue the warming trend. Wednesday offers highs in 
the 60s along the coast, areas inland into the mid to upper 70s and 
a few spots breaking 80. This looks to be a slight decrease from 
previous model runs, as the ridge to the north seems to have 
slightly weekend in the forecast update. 

Overnight lows will also see the opportunity to warm, but strong 
humidity recoveries and increasing marine influence will make the 
overnight warming trend much more modest.

&&

.LONG TERM...
Issued at 1257 AM PDT Wed Apr 29 2026
(Thursday through Tuesday)

The warming trend continues Thursday and Friday. For areas in the 
North Bay and potions of the rest of the SF Bay will see fairly 
similar temperatures on both days with the warmest interior 
locations breaking into the lowers 80s. The bigger difference will 
be felt in the interior south bay and the more interior portions of 
Monterey and San Benito counties: going from the lower 80s on 
Thursday to the mid to upper 80s for Friday. 

The trend breaks on friday as the ridge pushes east and weakens. 
High-level clouds build through Saturday as a low pressure and 
trough builds along the Pacific coast. This low will also call for 
expanding the marine layer both in height and inland push, and along 
with increasing onshore flow,  will allow for a strong cooling trend 
through the weekend. 

Models are in better agreement for good rain chances, but not a lot 
in accumulation from this low pressure moving inland. Drizzly 
conditions look to start Sunday morning with the chances for passing 
light showers building into that night and lasting into the work 
week. Models still need to iron out the finer details of the exit of 
this low, but there is good agreement that rain conditions could 
last into next Tuesday, before another ridge and warming trend
begin.

&&

.AVIATION...
(18Z TAFS)
Issued at 1050 AM PDT Wed Apr 29 2026

The patchy fog has cleared and low clouds have pulled back to the 
coast. There's high confidence in VFR conditions across all 
terminals this afternoon, with the exception of HAF. While we expect 
several hours of VFR conditions there, the stratus deck is 
expected to hang around just off the coast and could make a surge 
at any time. Winds will increase to a moderate onshore breeze with
the arrival of the sea breeze this afternoon. Low clouds are 
likely to return overnight as the marine layer continues to become
better organized. While we expect a fully formed marine layer by 
Friday morning, we're still in the transition Thursday morning and
the impacts will be more scattered and temporary. As such, the 
forecast confidence is rather low through the second half of the 
TAF period.

Vicinity of SFO...VFR conditions through the afternoon and
evening. Winds will shift to westerly and increase to a strong 
breeze over the next few hours. There is a 50-70% chance of MVFR 
stratus impacts Thursday morning, with the highest likelihood 
around 15Z. The window of likely impacts is only around 4-6 hours,
however, and there's a chance the terminal dodges these ceilings.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...There's high confidence in VFR conditions
through the afternoon. The chance for MVFR impacts steadily
increases from 40% at 06Z to 80% by 14Z. If they form, there a 
50% chance these ceilings will drop into the IFR category, at
least temporarily.

&&

.MARINE...
(Today through Monday)
Issued at 1050 AM PDT Wed Apr 29 2026

NW winds will increase to a strong breeze this afternoon. These
winds will build rough seas of 8 to 12 feet. Similar conditions
will persist through Friday before winds start to decrease
Saturday and continue improving through the weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM 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 to 9 PM PDT Thursday for Pt Arena 
     to Pt Reyes 0-10 nm.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PDT 
     Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt 
     Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 PM PDT Thursday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...Flynn
MARINE...Flynn

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Prepared by Boulder-Creek.com Weather at: Wed Apr 29 12:30:02 PDT 2026
From the National Weather Service