Technical NOAA Weather Discussion

FXUS66 KMTR 261119
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
419 AM PDT Sun Apr 26 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1031 PM PDT Sat Apr 25 2026

 - Drizzle and light rain continue into early Monday Morning.

 - Warming and drying into the work week.

 - Possible light rain next weekend.

&&

.SHORT TERM...
Issued at 1031 PM PDT Sat Apr 25 2026
(Tonight through Monday)

Most of the radar returns for rain have moved into the Central 
Valley, but some of the rain gauges are picking up a few hundredths 
of rain. This will likely be the theme for much of the night in the 
Bay Area and Central Coast: light rain and drizzle, barely showing 
up on radar. Shorter-term, high-res models agree on waves of light 
rain through the night with moments of drizzle possible in between. 

Rain chances reduce slightly into Sunday, but coastal drizzle and 
pockets of light rain will be possible with overcast skies.

This added moisture and lack of sunshine will make Sunday the 
coolest day of the forecast, with most populated area just barely 
breaking into the 60s and some of the interior mountains staying in 
the 40s.

Sunday night into Monday sees a slight increase in light rain and 
drizzle chances, but these chances look to erode and exit into late 
Monday morning. Overall accumulations from the weekend precipitation 
will stay on the light and non-impactful side. Cloud cover lingers 
through much of Monday, and along with good onshore flow, 
temperatures will stay on the cooler side. Highs on Monday look to 
be only a few degrees warmer than Sunday, and may arrive later in 
the day as cloud cover tries to thin before sunset. 

&&

.LONG TERM...
Issued at 1031 PM PDT Sat Apr 25 2026
(Monday night through next Saturday)

Skies look to clear in the early night on Monday, but some marine 
stratus looks to form into Tuesday morning, supported by a modest 
marine layer. 

From there, the overall pattern gets into an interesting mix. 
Ridging to the north, with a cutoff low to the south will lead to an 
active wind environment out to sea, but will greatly vary the 
weather overland. Coastal and slightly inland areas will see modest 
increases in temperature, but the reforming marine layer will 
provide cloud cover and more moisture in the air, preventing too 
much of a warm up. Areas outside of the marine layer will see more 
of the affects from the ridge, leading to much more notable warming. 
Highs look to climb into the 80s for the interior areas by the mid 
to late week, while the coast looks to peak in the 60s and the 
slightly inland areas build into the low 70s.

Longer term models hint at another trough digging into California 
coast next weekend. The increased onshore flow and cloud cover will 
call for cool conditions once again, along with some light rain. 
These chances for rain could be on the fragile side since the model 
guidance looks ..odd.. in the Pacific jetstream pattern. However, as 
odd-looking as the pattern looks, models are in ..oddly.. good 
agreement in the 200+ hour forecast. This'll be something to keep an 
eye on as the forecast develops, but maybe we're not done with rain 
just yet!

&&

.AVIATION...
(12Z TAFS)
Issued at 419 AM PDT Sun Apr 26 2026

Generally MVFR-low end VFR conditions prevail across the region, and 
will persist through the TAF period although ceilings are expected 
to lift slightly through the post-sunrise hours. Light showers will 
continue to move through the region through the morning, with low 
confidence of showers returning to the region this evening, but 
these showers should remain non-convective and not result in major 
impacts to the flight conditions. Breezy westerly winds will develop 
in the afternoon, diminishing overnight.

Vicinity of SFO... MVFR-low end VFR conditions through the TAF 
period. Winds will pick up from the west this afternoon before 
diminishing overnight. A low confidence and probability for showers 
will develop this evening into early Monday morning.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... MVFR-low end VFR conditions through the 
TAF period with westerly winds picking up in the afternoon. Showers 
will persist through the morning, with the chances dipping in the 
late afternoon and evening before a low confidence forecast for 
their return tonight through early Monday morning.

&&

.MARINE...
(Today through Friday)
Issued at 419 AM PDT Sun Apr 26 2026

Moderate west to northwest breezes persist through the middle of
next week before increasing to a fresh to strong northwest breeze.
These stronger winds will build rough seas of 8-12 feet in
exposed waters into the following weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...DialH
MARINE...DialH

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Prepared by Boulder-Creek.com Weather at: Sun Apr 26 06:30:03 PDT 2026
From the National Weather Service