It's simpler and a great deal less expensive to use some kind of artificial snow.There are plastic surfaces that might simulate snow. Magnets are a great deal of trouble.

i will agree with you sand that snow might be cheaper but with magnets there is no friction and if you were going up hill it would be much easier with magnets

If you discount the expensive technology you might have a point. I frankly doubt permanent magnets have sufficient power to support the weight of a rider without very powerful electric driven magnets in the ground. There is also the problem of no directional stability as the board goes as easily side wise as forward but maybe that is true for snowboarding as well. Since I have no experience in the sport my comments may be way off base.

skateboards and snowboards require friction to steer.

toastydeath that could be overcome very easily buy a simple bicycle like pedalsthat power a fan at the back with a small rudder behind it like a motor less hovercraft

also toastydeath you could also ride it like skateboard but u put your feet down to steer haven't u ever used a skateboard

Definitely possible. Although I think impractical, given the alternatives.

But Mag-Lev trains do this right now.

A big problem would be that the board would want to turn over all the time. The top of the board would be attracted to the floor, which causes it to flip over. After it flips, it will stick to the floor with great force. Try floating a magnet over a bed of magnets and you will see the problem.

This might be fixable using a gyroscope, but it would complicate the design considerably and I'm not sure it would work well anyway.

or we could figure out how to get superconductors to work at room temperature and float on earths magnetic field!!!

Halbach array.