Having trouble with curve direction

Hi all, 

I'm having trouble controlling the direction of a series of surface contour curves.

I've used the flip command before but since this involves several hundred curves that are randomly oriented, I'm not sure how to isolate only those in a certain direction. 

I'm guessing the guide curve would be useful but I can't find any indication of how the guide curve works or what its physical relation to the curves needing to be flipped is. 

Ideas?

Thanks much.