There's a couple of things you can do, open the Edit Template settings and look for Tubes, then Creation, in there you will find a box that switches between Following Normals and Following Path, try working with Following Path, just make sure you are in the perspective view and painting more upward as it will follow your stroke.
If your normals are pointed down, the easiest thing to do is flip your landscape over
Darkon
Red bellows of flame have blackened my stones
Convulsing my frame and cracking my bones
Hell's dragons of steel who roar in their chains
Crawl into my caves to suck out my veins.....
-The Mountain P.F.M.