I know offshore winds are preferable, but at what wind speed do onshore winds = bad conditions? Obviously a gale force 30 knot onshore wind is going to kill everything, but what if it was 5-10 knots? Would it still be bad and disorganized? What about cross-on-shore?
the answer isn't quite as simple as you have posed it, so I have to give me little more descriptive answer. All wind in the ocean that is blowing in the direction of the beaches you surf, will generate waves towards those beaches. When there is wind that is blowing, close to the coast and onshore, this creates small little tiny, unorganized waves that generate "choppy conditions". So, when there is no wind at all at the coast or nearby offshore, then this allow for the swells to approach the coast smoothly and without impediment from the nearshore environment. When you have offshore winds, the generated waves move away from the coast, which also doesn't impeded on the approaching swells. So, to get back to your questions, generally the lighter the onshore wind the better, but it really comes down to what are the winds doing in the entire nearshore environment (say 30 mile radius or so). Generally speaking tho, a 5-10 mph onshore will not be so bad, but will depend on more factors than just that.
"Generally speaking tho, a 5-10 mph onshore will not be so bad, but will depend on more factors than just that. " Thanks you for the detailed explanation. I can just look at the nws for nearshore winds forecast. That's easy. So, what are the other factors?
just look at the Swellinfo nearshore wind maps, that is your best bet. Other factors include the exact direction of the wind in relation to the coastline. Also, if there is any land masses or other features blocking the wind or wind chop, such as headlands or jetties, etc.
I didn't even realized you had those maps. Just found them. Thanks. oh and I'm guessing then if you have a bay beach break and wind is cross-shore then it won't mess it up at all since there is protection(ie land mass to side of the beach)