The answer to your question is this graph (see attached).
Put the time portion on the x-axis and the snowfall portion on the y-axis. It snowed lightly for a while meaning it took some time for the snow to fall. From zero, move the graph a little going to x-axis (to the right). Then it stopped, giving the graph a gap (just maintain a short horizontal line) then snowed heavily, meaning, the snowfall increases then it stops (move the graph to the x-axis a little higher then another short horizontal line). Hope this helps you.
