Hel-lo-ooooo, its 3 AM and raining, and you’re not up

That’r right, real cloud maven juniors get up in the night to experience all the raindrops they can after a droughty period.  Been up since a little after 3 AM;  its now 4:07 AM with an accumulation of 0.16 inches, a Dust-B-Gone amount, of which I have experienced exactly 100% of it as an audible event on a thin Arizona room roof.   Its great to have a thin roof so you can listen to the rhythm of the falling rain.  I feel like writing a song…

Quite nice, too, to hear this after SO MANY weeks of nothing except litho and bio meteors, i. e.,  dust and spores, Burrow weed and desert broom seeds floating in the air, and other untoward aerosols and particles that are best left on the ground.

Listening to rain on a roof can be used for meditation purposes, letting life’s questions resolve themselves without really trying, like, what are those ants going to do NOW with their wonderful little symmetric cones? Did they know it was going to rain and close the hole up in time?  Note tire tracks and resiliency of ants…  Says something about bouncing back after a disaster.

Why is it raining?  Got us a little stream of tropical air in the mid-levels of the atmosphere that had been meandering off Baja.  Mods saw this coming, maven was skeptical, but what’s great NOW is that we here in Catalina seem to be getting the most out of this little plume of moist air.  Here’s a sat loop:

First, this just in:  0.22 inches at 4:22 AM!  I am  beside myself with joy!

This just in (again): 0.30 inches TOTAL by 6 AM.  Fabulous.)

Here is the sat-radar loop from IPS Meteostar and below,  these sat and weather map images from the U of WA Huskies Weather Department showing the little blob of clouds “that could” (get here and rain on us).  You can see how that Big Trough (over Pac NW) swept it toward us, kicked it in the butt.  There is some writing on these images to help you understand them; point things out for you.  I really went out of my way here.

Today, at 3 AM as the rain begins.

Notice the big gap between the little cloud patch over us in the 2nd map for 2 AM this morning and the band coming across California. Means there’ll be a break in the rain here until late tongiht or early tomorrow morning when the Big Cold Front with the Big Trough arrives here. Until then, just the gusty winds and some pretty clouds, filling in from time to time, maybe some rain visible to the north of Catalina.

Yesterday’s clouds

Below are a couple of photos of those nice Altocumulus castellanus with virga that came in rolling in across the sky suddenly yesterday afternoon. Actually, when they grow into real shower preoducing clouds, they’re also transitioning in name to Cumulonimbus (Cbs) clouds, though they are weak ones, not like our summer variety.

If you really looked, you could see that the bases of the Altocu/Cbs were well above the freezing level by noticing all the snow virga dropping below the bases. The TUS sounding suggests that the bases were at 14,000 feet above sea level (around 11,000 feet above the ground) and at -5 C (23 F).

Too dry underneath for much of the precip to get to the ground.

3:09 PM. Castelannus on the move to Catalina.
3:50 PM. Nice crepsucular ray. (aka, crepuscular ray) below Ac cas and small Cumulonimbus clouds showing virga.
5:33 PM. A little grainy, but you can see some rain now reaching the ground.
Also, “red sky at night, sailor’s delight”. Since the storm was still approaching, you wonder how many sailors drowned listening to folderol like that.


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.