The phrase "as silently as falling snow" conjures up a sense of stillness and calmness. If you're looking for synonyms to describe a noiseless movement, you could use phrases like "as quiet as a mouse," "as hushed as a whisper," or "as soundless as a feather." Other possible options are "as tranquil as a lake at dawn," "as serene as the night sky," or "as peaceful as a chapel in the woods." These phrases can be used to describe someone walking stealthily, a cat sneaking up on its prey, or the movement of clouds overhead. All of these synonyms help to create a sense of tranquility and peacefulness in your writing.