How well do buoy readings correlate with nearshore conditions?

I've been fishing the San Mateo coast, and buoy 46012 (http://www.ndbc.noaa.gov/station_page.php?station=46012) seems to track pretty closely with what I experience right next to shore. Given it is a ways offshore, how much can it differ, and in what way?

Cheers,
Krishna

Could be like night and day; or can be identical... being 25miles offshore can make a world of difference to what is happening at the beach. I use it as a gauge as what's to come in the coming hours.....

Better to get a local "beach" surf report to determine conditions, there's usually one close by most popular locations; or just glass from the shore...

this one has worked great for me:
http://www.windfinder.com/

You could use the Point and Click weather thing on the left side of  Coastside Fishing Club's site to see what they extrapolate the conditions to be near shore - they seem to be pretty close to what I see.  And get on Surfline and check the cams.

Ditto on the surf report.  A lot of factors can contribute to changing the conditions by the time it reaches you.

Not so much in San Mateo cause it's really exposed but some spots are naturally protected from wind and swell, Santa Cruz, HMB and Linda Mar come to mind. Localized wind patterns can rough up or knock down swell and wind.  Reefs and kelp can absorb energy and smoothen things out....or roughen it up if it's big. 

If you really want to see how conditions correlate to your favorite spots, visit them when you're not fishing.  Go for a drive and compare them to the bouy report.

It depends on the bottom contours of where you're fishing.  Swell feels the bottom and refracts depending on the period.  Some spots will channel long-period swell into large surf, while others are small or even flat in long-period swells but begin to light up in shorter-period energy.  Ocean Beach (SF) is an example of the former; at 20 seconds, OB will have breaking waves around triple the swell height.

Surfline has done a series on swell refraction - you should search for it and take a look at all the examples, whether or not they're specific to the San Mateo coast.

Thanks for the answers, everyone. Regarding the focusing of long-period swell, I remember from my surfing days how Ocean Beach would usually light up with the greatest predicted wave height. Glad I'm not trying to kayak there.

I suggest looking at swellwatch. They give a visual representation of what the swell will be in different areas of the coast. The one for Monterey is a pretty good example, as it shows why SWS is always calm.