An ordinary beautiful day in Catalina, Arizona

Yesterday was one of those ideal days for us here in Catalina, the kind that draws visitors from all over the country to be together with us.   It was also kind of like that space-age, relaxo-elevator music; goes nowhere in particular with a hook or melody, or if there is one, its been eviscerated by sleepy, sedated violin players.

But, going back to yesterday’s weather, you could have taken a nice snooze in the sun yesterday afternoon, with only zephyrs to brush up against you, and with temperatures in the upper 70s, it was perfect for being unconscious for a bit, not having to worry about missing an ice crystal, a patch of virga, or an interesting pattern in middle-level or high clouds that you should write about in your weather diary, or document with a photo.

BTW, tops of the small Cumulus (humilis) were warmer than -10 C (14 F) yesterday, and so not one ice crystal or snowflake fell out of them.

6:52 AM. Residual Altocumulus castellanus from the little rainband that went through the night before last.


2:00 PM, from along Equestrian Trail, these picaresque small to medium Cumulus clouds, hold the ice, with dramatic shadows on the Cat Mountains.


Imagination going dry. I’ve talked about these kinds of days a lot. Will insert cow with cholla ornamentation here as a distraction. Might be best part of blog today.
3:44 PM. Cumulus clouds wither to Cu fractus as temperature falls. These days are so clear that it seems the earth ends just over the horizon.


Today’s clouds (should be interesting)

Should see a band of Cirrus and thicker ice cloud, Altostratus, off to the NW horizon by about mid-day.  Some Altocumulus likely around, too.  That band (you can see it here, courtesy of the U of AZ Department of Weather).   should arrive here here during the mid to late afternoon, producing a fair amount of gray.  But also there should be thinner portions before the main icy mass gets here.  In those thinner portions and leading CIrrus, there could be some some great patterns, like Cirrus uncinus, hooked Cirrus (“Angel’s hair”).     Lower Cumulus clouds are likely to form over the mountains during the mid-late afternoon. Could be really pretty overall if you can get out of your windowless office for a moment to take a peak this afternoon.

Freezing level and the critical -10 Centigrade (14 F) level for ice formation in clouds here in AZ will be lowering especially during the evening and overnight hours, and should lead to ice formation/virga as the clouds fill in later in the day and overnight. This means a chance for measurable rain here. Noticed just now that yesterday morning’s U of AZ mod (available after about 10 AM) did have a few hundredths in Catalina overnight tonight.  You can also see this progression of clouds, more or less, in the U of AZ model output from that yesterday morning’s run here1.


Will write more about later happenings in November when the prior forecasted rain in the models returns; its gone for now!

The End.


1The 11 PM AST model run from the U of AZ is not yet completed, so to HELL with it!  Hahaha, just kidding, but must move on to other chores, like digitizing old research flight videos from the University of Washington’s Cloud and Aerosol Research Group I was once a part of but now its over, plane gone, group gone.  Life changes, not always for the better, I can see that now.  I liked flying in clouds, hearing the graupel hit against the bubble where I had my head, standing on a little stool in the back.  BTW, here is what the bubble looks like.  I like to look at it even now and remember all the great cloud friends I got to know and write about.

The aircraft dome used by the Univserity of Washington on its research aircraft.  RIP.
The aircraft dome that was atop the fuselage of the University of Washington’s research aircraft. RIP. For awhile after retirement, I felt lost as many do. So, I would put this on my head, maybe while doing yard work in Seattle before coming here. It seemed to help the withdrawal I was feeling in those days. Great as a rain hat, too! It really didn’t look that bad.

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.