Thinking of visiting Huangshan on a trip to Shanghai but I am concerned about snow.

Actually I would like to go either:

1. When there is still frozen and there is snow - when it is winter on the mountain, or
2. When the flowers are blooming in spring - and it is warmer and green

With this in mind, when would a visitor be guaranteed winter weather and snow on the mountain?

And when could a visitor expect to enjoy green and spring colours on the mountain?

When is the very best time to see the sea cloud or the light of Buddha on the mountain?

Any reply would be helpful. Thank you for your help.