What is the introduction of "severe snow"? urgent

It snowed for the first time in more than ten years in Shanghai, but on this very beautiful day, a girl broke up with a boy who loved her deeply and left him without looking back. The boy just stood there, watching the snow fall and wet his face, and his heart was wet. The severity of snow or snow extends to the seriousness of girlfriend's breakup, and also extends the seriousness of boys' attachment to this relationship, and also reflects that boys' feelings for that girl can not be resolved by breaking up.