It's similar to Chicago in weather, if you live in the USA. I intend to use a steel mesh net to protect against large diameter hale (very rare, but very large), and for snow I have to either wait for the sun to shine long enough to melt the snow (remember that the cells absorb photon energy, even visible rays have a heating effect) or use a flipping mount which can rotate to dust off the snow from time to time.
It's probably not a good idea to put a mesh over them full time. It will definitely reduce your output by shading the cells. Any crystalline module (the ones most commonly available) will have greatly reduced output with only part of one cell shaded. It has to do with the way each cell works and the fact that they are connected in series. I would suggest that you only cover them when absolutely necessary. Most name-brand glass-faced panels are rated for hailstones up to 1 inch diameter. I don't know what size hail you get there, but if it's larger than that and relatively infrequent, covering them only when there's a chance of hail will get you better ROI than having a mesh over them.
As for snow, it's much easier to use a snow rake than to tip panels around when they're covered in heavy snow. Also more cost effective than buying movable mounts.
See here for a low cost snow rake:
http://www.youtube.com/watch?v=iG0ipbXxfZs