Arriving in local skies today: clouds, high and middle ones

Now that your camera battery is fully charged, you will be ready for the panoply of high and some mid-level clouds that will be arriving overhead today.  Should make for some great sunrise and sunset shots, but also daytime shots due to the interesting twists and turns in the Cirrus (ice) clouds that will float by.   Maybe later today,  Cirrocumulus and Altocumulus clouds will show up adding that extra dimension to sunset color.  Typically, in these situations, the first clouds on the scene are Cirrus at the highest levels (30,000 to 500,000 thousand feet above ground level (hahaha-just checking to see if you are reading this)–OK, 30,000 to FORTY,000 feet above the ground here on a warm day in Catalina-Tucson like today.

Next, with the moisture layer thickening downward from those high CIrrus levels as the day goes by, there might well be some Cirrocumulus (Cc) cloud patches, ones between about 15,000 and 25,000 feet above ground level.  Some times they evolve to Cirrus clouds within minutes after they form when they’re colder than -30 C (-22 F).     Cirrocumulus are short-lived clouds usually in thin, isolated patches.  They can have no shading by definition and they can display the most delicate granulations imaginable.

But those patterns change in seconds to a few minutes, and you have to have your camera by your side to get the best shots of that sort of thing, like other nature photographers who shoot birds and stuff like that.  Did you realize that by shooting clouds that you were becoming a “nature photographer”?  Often these patches can be higher level lenticular clouds (thin sliver clouds) that have smooth portions on the upwind side and then break into tiny elements downstream.

Finally, as the day comes to a close, some Altocumulus clouds might arrive on the scene; if not today, then by tomorrow at daybreak.  They may also be in the form of sliver clouds, lenticulars that hover downwind of mountains–look to the northeast of Mt. Sara Lemmon today.   But, given the high temperatures aloft, indicating that the Altocumulus clouds will have more water in them than on a cold day, look for some sprouts and little turrets.  That extra warmth, say at 15,000 feet, results in an enhance updraft when clouds form at those levels because condensation releases a small amount heat to the atmosphere inside the clouds.  That bit of extra heat is likely to lead to those itty bitty turrets (castellanus species of Ac)

Here is an example of the delicate Cirrocumulus (Cc) clouds we may see today and tomorrow.

No rain seen in models for two weeks now, but remember the wild chaos of the predictions beyond six days now, as indicated in “spaghetti plots.”  That means rain for southern AZ may well show up again soon, along with that horrific early April cold spell.

The End.

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.