Technical NOAA Weather Discussion

FXUS66 KMTR 291943
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1243 PM PDT Sat Aug 29 2026

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

.KEY MESSAGES...
Updated at 1240 PM PDT Sat Aug 29 2026

 - Cooling trend continues through at least midweek

&&

.SHORT TERM...
Issued at 1240 PM PDT Sat Aug 29 2026
(This evening through Sunday night)

Mostly sunny sky conditions have return to the region this 
afternoon. This will lead to warmer conditions today over the North 
Bay with the lack of mid/upper level high clouds. However, 
temperatures across the region with be a few to several degrees 
below normal as an mid/upper level low pressure system moves into 
the Pacific Northwest and British Columbia. 

The marine layer is forecast to deepen through the weekend. However, 
with clearing skies off of the North Bay coast this afternoon, less 
confidence for a return of stratus/fog overnight and into Sunday 
morning. Still anticipate at least a patchwork of stratus/fog to 
develop late this evening and moreso into Sunday morning along the 
coast and into the adjacent valleys. For Sunday, expecting more of 
the same as troughing persist along the West Coast. 

&&

.LONG TERM...
Issued at 1240 PM PDT Sat Aug 29 2026
(Monday through next Friday)

A reinforcing trough develops and begins to deepen off of the 
Pacific Northwest coast through the middle of the upcoming week. As 
a result, afternoon temperatures will be some 5 to 15 degrees below 
normal for this time of year. This will system will likely bring 
rainfall to the Pacific Northwest. By late week, the NBM is 
suggesting a better chance of rain/rain showers as the trough off of 
the West Coast continues to deepen and potential drags a weak 
frontal boundary across the region. There is still low to 
moderate confidence of this occuring. 

&&

.AVIATION...
(18Z TAFS)
Issued at 1151 AM PDT Sat Aug 29 2026

VFR prevails this afternoon as moderate onshore winds increase with 
a few sites experiencing strong gusts around 20 kt in the late 
afternoon. Onshore winds become gentle through the evening into the 
overnight hours. The OAK 12Z sounding from this morning measured the 
marine layer at a depth of ~1400 ft. An upper level low situated 
over our area is expected to deepen the marine layer further. A mix 
of IFR to low-end MVFR ceilings return tonight across the terminals 
with medium confidence on arrival times and ceiling heights.

Vicinity of SFO...Northwest to westerly moderate winds prevail into 
the evening with frequent strong gusts around 20 to 25 kt at SFO.
OAK may experience occasional 20 kt gusts during the afternoon. 
Winds ease after sunset into the overnight hours. Relied on 
persistence from last night on stratus arrival with medium 
confidence for MVFR ceilings. Some model guidance hinted at the 
possibility for IFR ceilings similar to last night, but given the 
expected deepening of the marine layer, the TAF advertises low-end
MVFR.

SFO Bridge Approach...Occasional strong gusts through the afternoon. 
Cloud cover may be patchy overnight, depending on how well organized 
the marine layer becomes. Otherwise, similar to SFO.

Monterey Bay Terminals...VFR through the afternoon with an early 
arrival of IFR ceilings around sunset for MRY and after sunset for 
SNS. Moderate onshore winds prevail through the day and diminish to 
gentle overnight. 

&&

.MARINE...
(Today through Thursday)
Issued at 914 AM PDT Sat Aug 29 2026

Northwest winds remain fresh with strong to near gale force gusts
today into Sunday night. In response, wind driven seas build to 
rough this afternoon and steadily subside to moderate through next
week. A long period southerly swell also peaks today around 17 to
18 seconds and gradually diminishes by Sunday night.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for Mry Bay-Pigeon Pt 
     to Pt Pinos 0-10 nm.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt 
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory until 9 PM PDT Sunday for Pigeon Pt to Pt 
     Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Navarrete
MARINE...Navarrete

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Prepared by Boulder-Creek.com Weather at: Sat Aug 29 14:30:02 PDT 2026
From the National Weather Service