June 13th–a full observational day

As the day rolled forward in time as they do pretty consistently, I was really happy for you having so many things to log in your cloud diary and maybe report to neighbors who might not have been so observant as you yesterday; the various types of clouds you saw, fun dust devils here and there spinning their way across Catalina, Cumulus clouds, a couple of which grew into Cumulonimbus clouds, and even produced a thunderstorm way over there in Safford.  You could see that one from here, too. And there was a spectacular chances for you to test your ice-in-clouds acuity score.

Let’s go over yesterday’s clouds and make sure you got them right; but remember, don’t feel bad if you missed something.  Cloud maven person will always understand and forgive those who might call a cloud by its wrong name.  Believe or not, even CMP has done so1.

10:56 AM. Altocumulus lenticularis patches underlain by a tufts of Altocumulus castellanus.
11:51 AM. Mostly Altocumulus castellanus and floccus (no firm base, just a tuft).
CMP’s cloud chart points out that rain might follow in 6 to 196 h when this form of cloud is observed. It indicates strong instability at this cloud level.
11:53 AM. Fun dust devil goes across Catalina. No jumping castles were harmed.
CMP used to jump in dust devils when he was kid when they came across the school yard at playtime. Maybe you did, too.
1:17 PM. Small Cumulus (humilis) begin erupting over the Catalinas. Portent: moderate.
1:54 PM. Cumulus fractus over Saddlebrooke and points NW. Not much going on in the high mountains, either, (as would be seen by tops of Cumulonimbus clouds) suggesting a dividing line in the moist plume over us; drier to the north, more moist to the south.
2:24 PM. “Wow!”,  you thought, if I may interject one for you that you should have had yesterday viewing this cloud. The real look of our summer rain season (aka, “monsoon”), a tall, thin Cumulus congestus cloud.
2:24 PM. And at the same time, a Cumulonimbus capillatus incus (icy anvil) has formed over there toward Safford! Now summer’s on! Safford reported a thunderstorm about this time.
2:54 PM. We really haven’t had an Cloud Maven Junior (CMJ) ice IQ test in quite awhile, and so I thought would give you a little surprise quiz today in the following photographic sequence.  Here we see, while not driving I might add,  that would be crazy, to add that bit more, we see a protrusion from a Cumulus congestus cloud.  Will it turn to ice?  And if it did, when exactly did you know that?
2:57 PM. Ice in the top tuft yet? You have 10 seconds to come up with an answer.
2:59 PM. “You are so ice!”  Cloud Maven Person got quite excited and has made a call for you, prematurely.  See how the finer detail has started to disappear as the droplets evaporate and the slower evaporating ice (in much lower concentrations) begins to dominate the appearance of the little tuft.  Compare the newer tuft on the right and its ruffled appearance to the little, detached tuft on the left.  In the one of the right, the much higher concentrations of droplets still dominate providing all kinds of visual detail, though ice would undoubtedly be present inside it and about to take over.






























3:04 PM.  Secret's out!
3:04 PM. Secret’s out!  The little tuft shows its ice.  Poor guy has no droplets any more, is just a defunct ice cloud on its way to evapo-oblivion.  Note icy fallout from the trunk of the original cloud now.  And, you now know that those sharply outlined turrets in the center of the photo have a ton of ice in them, though droplets are also present (soon to be gone as in our icy little remnant to the left).


The End

No further weather ahead of any interest to a CMJ, anyway.  Darn.

















































































































1As a kid, I think I once called an Altostratus translucidus an “opacus.” It was pretty embarrassing.

By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.