First you had the rarely seen “Aircraft Produced Ice Particles” (APIPs, or “High Temperature Aircraft Contrails” (HTACs) in supercooled Altocumulus in the afternoon. Contrails were being produced in clouds that were “only” -20 C to -30 C (-4 to -22 F) and aircraft contrails were thought to be impossible at those temperatures, but rather, only at much lower ones, below -40 C (-40 F) or so.
Then, just after sunset, the heavy layer of Altocumulus produced a sun pillar! I was out in Saddlebrooke having dinner with friends after sunset, so had to leave dinner for about ten minutes, but I was so excited for you that I had to see it for myself, too. Since it would have been obscenely rude to tell my dinner friends the true reason why I left, when I got back after many minutes I told them I had to pee, and that seemed to go over pretty well I thought1.
Below, a coupla shots of that sun pillar I got while “peeing” on your behalf:
Let us look at our sounding and see if we can see how cold those Altocumulus clouds were:
Here are some of the magical, rare scenes from aircraft making ice canals in those very cold supercooled Altocumulus clouds:
Skipping to the chase, as hard as that is to do, this trail really lit up as it got to the 22 degree point from the sun, where mock suns and such happen, producing a rainbow of colors due to iridescence, a rainbow producing by very tiny ice crystals in this case, of the order of a few microns in size.
Guess about today’s clouds
Maybe a few Cirrus, patch or two of Cirrocumulus, and likely lenticular clouds, particularly off to the north.
The big storm everyone’s talking about?
Oh, yeah, baby, its still comin’, begins on Wednesday, New Year’s Eve in the afternoon, continues for about 24 h off and on.
Bracketing possible precip totals: still 0.25 inches on the bottom (10% chance of less), 1.50 inches on the top (10% chance of more). Average of those two often brings the best estimate, which would be about 0.87 inches, somewhere in there. You know, when you deal with wobbly cut off lows, you just can’t be real confident in how much rain they’ll bring. However, it looks like the north part of the State will get the brunt in snow, which will be great for the water situation.
1It would be fun to hear what your excuses were as a “CMJ”–Cloud Maven Junior, if you were in a similar predicament last evening and HAD to see that rare sun pillar, rather than meet new people at dinner who wouldn’t be able to understand you anyway because you are compulsed like that; leave a great dinner to go outside in cold air to take cloud photos.
Well, nobody really understands a CM.
I remember in grammar school and Junior High in Reseda, CA, when kids teased me on clear days , saying, “Hey, Artie! Is it gonna rain today?” Then they would laugh at me for being a CM before I even answered the question, knowing all the while what the answer was going to be. Still, out of civility, I would answer them: “No, we’re having Santa Ana conditions now and it can’t rain for at least five days”, but they would still be laughing in the midst of my explanation about why it wasn’t going to rain. Kind of a sad scene when you think about it, that is, how mean kids can be to kids who are different. Later, when I became a pretty good athlete, they liked me, which shows how important athletics is over knowing stuff, and helping you “fit in.”
2 “Pristine” means that can’t be gunked up by having collected cloud droplets on their faces because then the optics, like sun pillars, mock suns, that kind of thing can’t happen if the crystals are messed up with droplets on them or a lot of extra hexagonal arms sticking out of them, as in bullet rosette ice crystals.