How to call model.find method synchronously in node / loopback?

I am using a custom model and trying to filter it in a loop using find method. e.g. given below

for i = 0 to n
{
var u = User.find( where { name: 'john'});
}

It doesn't work.

Also, if I use the following

for i = 0 to n
{
User.find( where { name: 'john'}, function(u) {... } );

// How do I call the code for further processing? 
}

Is there a way to call find method synchronously ? Please help.

Thanks