Clouds About Town

Last week I had a great time giving a virtual talk on clouds to about 25 members of Amherst Neighbors. One of the things I love most about "talking clouds" is hearing what other folks love about cloud spotting. And best of all is when audience members share their cloud photos. Case in point, these photos which Rebecca Reid sent me the next day. These are just a few of the ones she shared, but I am holding some back for a future post. Her collection included some fairly rare formations, including a Fallstreak Hole (or something very comparable) and Asperitas, neither of which I have seen outside of photos. The other two views, while maybe not quite as rare, are classic and beautiful examples of cumulonimbus (storm clouds) and what I suspect is a split cirrostratus and cirrocumulus sky. Enjoy, everyone - and thank you for sharing, Rebecca!

More to follow in future postings.

Fallstreak Hole (photo by Rebecca Reid). A fallstreak hole is a large gap, roughly circular or elliptical, that can appear in cirrocumulus or altocumulus clouds. The holes are caused by supercooled water in the clouds suddenly evaporating, and may be triggered by passing aircraft. Rebecca's cloud may not be exactly a Fallstreak Hole (it's not a complete gap in the center), but it's a similar formation, at the very least.

Photo of clouds that I believe are Asperitas, or at least a close cousin. Asperitas is a distinctive, but relatively rare cloud formation that takes the appearance of rippling waves. These wave-like structures form on the underside of the cloud to makes it look like a rough sea surface when viewed from below.

Cumulonimbus (classic storm clouds). Photo by Rebecca Reid

Depending on how elevated these clouds are (and it's hard to tell without land-to-sky context), this is a beautiful example of a split blanket of cirrostratus (the smooth white clouds in the upper left) and cirrocumulus (the puff ball covering in the lower right half of the field). "Cirro" is for high level clouds. If, however, this is happening at mid-level, lower down, it would be altostratus and altocumulus. Just lovely. Photo by Rebecca Reid.