FXUS66 KMTR 202342
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
442 PM PDT Wed May 20 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 256 PM PDT Wed May 20 2026

 - Diurnally driven winds, with onshore winds during the 
   afternoon and early evening. 

 - Warm and dry weather through Thursday leads to elevated fire
   weather concerns for the interior Bay Area and Central Coast. 

 - Above normal temperatures continue through midweek with
   seasonal temperatures returning by the upcoming weekend.

&&

.SHORT TERM...
Issued at 256 PM PDT Wed May 20 2026
(This evening through Thursday)

A deeper marine layer, ~750 ft in depth, and stratus has resulted in 
cooler conditions near the coast so far this afternoon. Temperatures 
there are in the upper 50s to mid 60s. However, inland areas are 
well on their way to the upper 80s to lower 90s. Breezy onshore 
winds are likely to increase this afternoon and peak early in the 
evening with gusts up to 30 mph before easing overnight. With low 
clouds hovering near and along the coast, expecting a greater 
potential for stratus to spread inland through the Golden Gate and 
into the Salinas Valley tonight and into Thursday morning. 

For Thursday afternoon, expecting little change compared to today 
with mostly sunny sky conditions across the interior. The higher 
elevations above 1000 feet will remain critically dry (10-20%) with 
poor overnight (less than 30% in spots) humidity recoveries. 

&&

.LONG TERM...
Issued at 256 PM PDT Wed May 20 2026
(Thursday night through next Tuesday)

Temperatures on Friday will heavily depend on how deep the marine 
layer becomes as the Bay Area and Central Coast remains between the 
high pressure to the west and troughing to the east. The stronger 
the marine layer, the less time there is for daytime heating 
(especially where the stratus hangs around for much of the day). 
Temperatures gradually cool over the weekend as troughing develops 
to the north. 

Then, cooler and potentially unsettled weather returns for early 
next week as the aforementioned trough drops southward across the 
West Coast. As such, the 6-10 Day Temperature Outlook from the CPC 
indicates temperatures leaning below average with the same outlook 
for precipitation leaning above. Again, above average for this time 
of year may bring either drizzle and/or very light rain to the 
region as we go deeper into our "dry season". All that said, please 
keep up to date with the latest forecast information over the next 
few days. 

&&

.AVIATION...
(00Z TAFS)
Issued at 441 PM PDT Wed May 20 2026

Currently VFR at all terminals with the exception of IFR at HAF. 
Moderate to high confidence on IFR conditions at HAF, MRY, and SNS 
with VFR elsewhere tonight. Diurnal winds will prevail.

Vicinity of SFO...Currently MVFR with gusty northwesterly flow and 
haze. High confidence in VFR and diurnal winds prevailing through 
the TAF period; however, FEW/SCT IFR clouds will be possible on the 
north side of the terminal if stratus sneaks through the Golden Gate 
Gap.

SFO Bridge Approach...The San Mateo Bridge Approach has a lower 
probability of IFR conditions.

Monterey Bay Terminals...Currently VFR with northwesterly flow at 
MRY and MVFR with northwesterly flow and haze at SNS. Moderate 
confidence on IFR conditions developing at the terminals tonight. 
VFR is expected by late morning with IFR stratus sticking close to 
the coast during the day.

&&

.MARINE...
(Tonight through next Monday)
Issued at 441 PM PDT Wed May 20 2026

Hazardous conditions for small craft will continue through
Thursday  for the northern outers due to rough seas and strong
northerly  breezes. Elsewhere, moderate northwesterly breezes and
moderate seas  will prevail. Conditions improve into the weekend
as seas and  northwesterly breezes become moderate.

&&

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

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Sarment
MARINE...Sarment

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Prepared by Boulder-Creek.com Weather at: Wed May 20 18:30:03 PDT 2026