In the Rocky Mountains the snow is 40 inches deep
Intial depth of the snow on mountain = 40 inches
After the second snow storm
The depth of the snow increased by 21%.
i.e. depth of the snow increased by 21%. of intial depth = depth of the snow increased by 21%. of 40
So,

Thus, depth of the snow increased by 21%. = 8 inches
So, the final depth of snow = Intial depth + Increased depth
The final depth of snow = 40 + 8
The final depth of snow = 48 inches
Answer: 48 inches
After the snow storm, the depth of snow is 48 inches