Once again we had a brief period of optical fireworks, as a rare “circumzenithal arc” developed overhead of Catalina in some Cirrus strands. Hope you saw it and bragged about it to your less observant friends. After saying that, follow it up in a moment of feigned reflection, speaking to no one in particular, with a comment about “how sad it is when people don’t notice the beauty in the world around them.” Your friend will appreciate what a sensitive person you are. That would be great!
Here are the scenes so many missed because you only have SECONDS to see them light up, peak out and disappear (but I saw it!):
Whew, that was pretty much the climax of this event. Began to relax. calm down, as the possibility of seeing more “arcs”, began to fade. No more Cirrus was upwind.
Most of these I have seen have been due to aircraft-produced ice particles (“APIPs”, as named by Rangno and Hobbs way back in 1983, J. Appl. Meteor.), i. e., contrail like events produced by aircraft that occur at much higher than expected temperatures in “supercooled” clouds.
No Altocumulus clouds were around this line of Cirrus uncinus clouds at the time this passed over, though there were plenty around, however. Likely this was produced upwind by an aircraft in Ac clouds, and the Altocumulus droplet clouds just evaporated.
These aircraft produced ice clouds start out having prodigious, unnaturally high concentrations of ice, thousands per liter, and that in itself would lead, due to the competition of vapor among them, to tiny, pristine ice crystals like solid columns that would refract the sun’s light. So, that’s my thought on the origin of this line of Cirrus uncinus, the line itself raising suspicions about its origin. It extended much farther than shown in these photos, and was intermittent, likely reflecting where the Altocu was, and where there were holes in the coverage.
Then, a great cloud iridescence:
Next, holey stuff.
Never seen anything quite like what happened in those quasi-laminar clouds that developed later in the morning over and near the Catalinas, so must show :
Well, as you could imagine, I could go on and on about this, with many more photos, but need to quit here. And besides, it pretty much cleared off in the afternoon, and the hole phenomenon ended.