[suavros (OP)]

Would it be possible, and I suppose cost effective in the long-term, to develop some type of helium filled tarp that would cover a high population density area, like Manhattan for instance, when it snows, in order to prevent snow plowing, roads being damages, car accidents, mess, etc. There would have to be some type of way where the snow would melt on contact and drain in holes/tubes. I feel like this would be a great idea, with many benefits, but would it be possible to create a 20 square mile 'helium tarp' in the case of Manhattan?

[Geezer]

There might be a couple of minor issues to contend with, like;

How would you prevent the helium from asphyxiating the entire population?

How would you get rid of all the soot, CO2, CO1 etc that would either poison or asphyxiate the population?

How would sunlight penetrate the barrier to alllow plants and trees to grow?

[Bored chemist]

Helium is expensive. You would have to use hydrogen. Remember to print "no smoking" on the tarp.
Also, this thing would have to hold up thousands of tons ( perhaps millions) of snow. How big a balloon would that take?