Gray clouds appear over Catalina, then leave

You have to work with what you have.  Imagine a day without crime, or an exploding balloon,  traffic accident, tax folderol, etc.,  and the television news for that day is cancelled, not worthy of air time, maybe replaced with one of our favorite PBS programs, like, “The Desert Speaks”?

Had a nice lenticular a couple of days ago, in case you missed it.

Wasn’t up much that day; you know, the FLU!  Its out there.
7:54 AM yesterday morning. Stratocumulus cloud tops Samaniego Ridge.  Was actually hoping that the encroaching clouds would be cold enough to form ice even though models said no, tops would be warmer than -10° C  (14°F) or so.  However, in windy situations such as we had atop the Catalina Mountains, clouds like these can leave water in the form of “rime ice” on trees.  How pathetic is that; we can only hope for some mountain sky water1 through riming, not actual precipitation?
8:34 AM. Looks pretty good over there beyond Eagle Crest.   Maybe there will be some ice in this deck after all… Or is that dust under that distant band?
8:45 AM. Wonder if something special is going on over there, maybe I should know about?
8:46 AM. Not much going on directly upwind, though Tucson Mountains obscured in dust. Of course, any cloud band is going to propagate, spread in, from the NW yesterday.
9:49 AM. Looking better. Now, if only some ice would form…
10:01 AM. Almost looks like precip. but its not.  Note clouds still topping Sam Ridge, likely lots of rime icing gong on higher up, toward the middle and top of this shallow layer since the droplets are too small at cloud base to produce riming.  Higher up in the clouds like these, the droplets will reach the size (about about 15 um in diameter) where they are large enough to collide with objects and freeze onto them.
10:01 AM. A closer look at a dust-infused crespucular ray that almost looked like fine precip.
11:56 AM. The Stratocumulus deck is thinning, but an anomalous darkening  has appeared, either due to the shadow of a lenticular cloud or a large space vehicle on top of the lower Stratocu.  Note that the clouds have now lifted above even Ms. Mt. Lemmon.  No more riming to add to our aquifers.  No actual  precip was recorded in the county.
12:38 PM. The clearing side of our little cloud band as it slud by, the complete clearing zone to the right.  Tucson Mountains still mostly obscured in dust, though it really wasn’t that windy here.
1:41 PM. Waiting for the electrician…. If you can find a sunny porch out of the wind, its amazing how pleasant 52°F can be. BTW, if you need an electrician badly, but it conflicts with open heart surgery, its best to cancel the open heart surgery; you may never get another chance to get a licensed, bonded electrician out, but you can always have open heart surgery on another day.  The above, our former home, rented for so long, now in the process of being sold.  (boohoo).

No real change apparent in the drought pattern.

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.


  1. That’s a fine couple of crepuscular ray shots, Art! I saw something like it here yesterday myself. Now, what’s this about “open heart surgery”?? Yikes!

  2. Thanks, Roland! Same to you. I’ve answered a couple of your comments via e-mail, but they’ve both bounced. ???


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