photo #4619636

NOT Hunter Biden clouds. Elizabeth Rand (Cloud Appreciation Society Member 61,362) spotted these rolls of low cloud extending over Lake Thun in the Bernese Alps of Switzerland. She was staying at a Buddhist retreat in Beatenberg and on a walk to see the peaks her father skied as a boy. As she looked at the clouds across the wide valley, their parallel rolls seemed to play an optical trick. Were they aligned vertically, one above the other, or horizontally, one next to the other?Strange as it may seem, these cloud rolls are likely all at the same level. They formed orographically, which just means by the interaction of airflows with terrain. They’re probably best described as Stratocumulus lenticularis and undulatus clouds. The wind was blowing up over the long mountain ridges behind Elizabeth and in a rising and dipping flow of waves ahead of her, which were invisible but for the rolls of cloud that developed at each wave crest. The optical illusion comes from the fact that the nearer and middle rolls of cloud are more broken and fragmented than the thicker, further one. Also, the gap between the nearest and middle rolls is shorter than that between the middle and distant ones. These characteristics both contrast with the usual perspective effect of distant things looking smaller and more bunched up, making you think instead that one cloud is above the other rather than ahead of it. As Joni Mitchell put it in her 1966 song Both Sides Now, ‘I've looked at clouds from both sides now, From up and down and still somehow, It's cloud illusions I recall.’