October 21, 2012 by Dave Bonta Cumulus clouds at two different heights: the lower ones move twice as fast. Lower still, a scattered flock of robins going the opposite way. Share on social media Click to share on Bluesky (Opens in new window) Bluesky Click to share on Mastodon (Opens in new window) Mastodon Click to share on Threads (Opens in new window) Threads