Technical NOAA Weather Discussion

FXUS66 KMTR 290454
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
954 PM PDT Tue Apr 28 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1222 PM PDT Tue Apr 28 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 1222 PM PDT Tue Apr 28 2026
(This evening through Wednesday)

Temperatures this afternoon will warm into the upper 50s to mid 60s 
near the coast and the interior reaching into the mid 60s to lower 
70s under mostly sunny sky conditions. These temperatures are 
slightly below seasonal averages, generally up to 5 deg F cooler and 
up to 15 deg F cooler in the higher terrain. This is as a short-wave 
trough lingers over the Bay Area and northern Central Coast. 

Expecting low clouds to return to the coast and locally inland into 
the coastal adjacent valleys overnight tonight and more so into 
Wednesday morning. There is a greater probability of this to occur as 
the marine layer is forecast to deepen overnight to around 1,000 
feet. 

On Wednesday, as low clouds gradually retreat to the coast, 
temperatures rebound to near or slightly above (up to 5 deg F) 
seasonal averages. However, cooler temperatures will persist in the 
higher elevations. This is as high pressure begins to build eastward 
from the eastern Pacific. 

&&

.LONG TERM...
Issued at 1222 PM PDT Tue Apr 28 2026
(Wednesday night through next Monday)

The warming trend will continue into late week with interior 
temperatures up to 10 deg F above normal by Friday as the 
aforementioned ridge builds overhead. Friday is when we have the 
greatest probability of reaching or exceeding 85 deg F across the 
interior, with the warmest being across the interior Central Coast 
(greater than 50%). However, the marine layer will remain in place 
and keep temperatures cooler near the coast. This is as the ebb and 
flow of late evening and overnight stratus returns to the coast and 
coastal adjacent valleys each day. 

A slight cooling trend is forecast to return on Saturday as a 
mid/upper level low drops southward out of the Gulf of Alaska. This 
low pressure system will eventually become a cut-off low with high 
pressure building across British Columbia late in the upcoming 
weekend setting up a Rex block. This would bring drizzle and/or 
light rain to the coastal waters Saturday night and into Sunday. 
Then, as the mid/upper level low shifts inland Monday and Tuesday, 
it will bring increasing chances for drizzle and/or light rain to 
the Bay Area and Central Coast. Rainfall amounts from this system 
are expected to remain light, however they will make for wet 
roadways across the region. 

&&

.AVIATION...
(06Z TAFS)
Issued at 1000 PM PDT Tue Apr 28 2026

Starting to see some patchy stratus develop near HAF and Monterey
Bay as of the 06Z. Elsewhere VFR with no notable clouds. Winds
continue to ease and will do so through the night. Still 
expecting some patchy stratus to impact terminals Wednesday AM. 
That being said, if a trend is your friend the 00Z models have 
trended slightly drier across the N and E Bay for cloud 
development. Not enough of a trend to remove CIGs, but conf is 
less. VFR most areas Wednesday afternoon except KHAF.

Vicinity of SFO...No big change from 00Z tafs. MVFR CIGs 
developing early Wednesday. Lower conf for sure as cigs will be 
drifting in from the N and barely hitting the terminal. 

SFO Bridge Approach...VFR for most of tonight. Less clouds for
Wednesday AM. CIGs more likely north of the approach for AM rush.

Monterey Bay Terminals...CIGs knocking on MRY's doorstep. SNS CIGs develop
later tonight. Both terminals then clear during Wednesday mid 
morning.


&&

.MARINE...
(Tonight through next Monday)
Issued at 938 PM PDT Tue Apr 28 2026

Northerly flow will increase as high pressure builds to the
north. Fresh to strong breezes will result in locally hazardous
conditions to small craft, especially the outer waters north of
Point Reyes. The stronger winds will also produce a fresh swell of
8 to 12 feet through Friday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM Wednesday 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 Wednesday to 3 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 3 PM PDT Thursday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...MM
MARINE...MM

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Prepared by Boulder-Creek.com Weather at: Tue Apr 28 22:30:03 PDT 2026
From the National Weather Service