Introduction[]
Self-Explained. The problem was the fact that the height of snow storm was over-exaggerated, as well as the fact that the staff stated that the density of snow was over-exaggerated as well. I am going to try and fix that.
Calculation[]
I'm going to make this really quick, and with changed results.
Diameter of Earth = 12472000 meters = 916 px.
Pixel Scaling = 12472000/916 = 13615.72052402 m/px.
Radius of snow = 199 px = 2709528.4 meters.

Height of snow = 27 px = 367624.4541485 meters.
Storm is originally cylindrical in the page, if you consider the height the snow took. In addition, i see no way of measuring it other than that.
Volume = 8.478942307629e18 m^3.
Now, for the density of snow. It was really tricky, but to be accurate and frank, i think that it will be New Snow, since the snow was apparent on the ground from the storm, so i shall use that.
Density of new snow = 70 kg/m^3.
Mass of snow created = 8.478942307629e18 * 70 = 5.93525961534e20 kg.
Clouds occured as well there. So i will assume their own weight as well.
Radius of storm = 2709528.4 meters.
Height of clouds = 8000 meters (The standard height of storm clouds).
Volume = 1.8451312935138e17 m^3.
Density of clouds = 1.003 kg/m^3.
Mass of clouds destroyed = 1.8451312935138e17 * 1.003 = 1.850666687394e17 kg.
Total mass = Mass of snow created + Mmass of clouds destroyed = 5.93525961534e20 + 1.850666687394e17 = 5.937110282027e20 kg.
Distance the storm traveled = Radius of snow * 2 = 2709528.4 * 2 = 5419056.8 meters.
Timeframe = 10 seconds (Accepted).
Speed of the storm = 5419056.8/10 = 541905.68 m/s.
E = 8.71751e31 Joules = 20.835 Zettatons of TNT (Small Planet level).
Conclusion[]
Esdeath's Ice Storm Commander-In-Chief Redux 3 = 20.835 Zettatons of TNT (Small Planet level).