Thundery trace; expect more than that today

(A note:  I am not getting WYSIWYG in what I am writing and what is posted in WP.  This is SO FRUSTRATING!  True I am a bit of an amateur at WP,  but those spaghetti plots that start the blog are SUPPOSED TO BE AT THE END OF IT as I see them in the draft, not absorbed in the “gallery” as well, dammitall!)  Computers and sofware are going to kill me, I am sure.  Where are my pills?!

Another promising start to a summer day today in Cat Land, as was yesterday since we have another cloud filled morning, some clouds having weak rainshafts indicating glaciation in the turrets sprouting from today’s layer.  And, there’s been a slight uptick in moisture over us, which raises the chances for measurable rain in Catalina today.  We also have support for this contention in the great U of A local model forecasts here, based on last night’s 11 PM AST run!  Yay!

Below, the photographic diary for yesterday starts begins with the Altocumulus opacus layer, with more than one layer up there.  Then, after the usual thinning-dissolution of that layer in the morning, the welcome sight of baby Cumulus beginning to appear over Mt. Lemmon by noon.  Those Cu steadily inflated reaching the “glaciation” level by 1:31 PM, a welcome sight after the “dud” Cumulus clouds of the prior two days.

After our first thundery spell, several new thunderstorms developed to the NW and E-SE over the Catalinas late in the afternoon,  but again, produced only another trace in a 20 minute or so of “very-light-rain-its-not drizzle” (one of the recurring themes here).

Since I can’t add more captions after the icy sprout, a WP problem, the times of the last few photos are, 1:53 PM, 2:08 PM, and finally, another great sunset sequence, some distant Cumulonimbus to the NW and another blazing sunset underlighting some virga from the remains of our last thunderstorm, these taken at 7:30 PM.

The Weather Ahead, way ahead:

We’re always on pins and needles this time of year, hoping for the best summer rains we can get, at least I am. The transformation of the desert into green again during the summer, after the spring greening,  is one of THE most rewarding aspects about living here in the summer, flying ant swarms aside.

Below are the “spaghetti” plots from NOAA that give us some clue about the reliability of the longer term model forecasts.  These are for the afternoon of July 19th, some ten days from now, and the afternoon of July 23rd.  Both plots below strongly indicate that the circulation pattern is ripe for good summer rains here between now and the 24th.  Doesn’t mean that every day will have rain, but it does mean recurring summer rains are likely with no long breaks.  That black region over the SW indicates a high probability (not certainty!) that our big fat SW summer anticyclone will be well positioned for good summer rains here.  In contrast, if that black area was OVER southern Arizona, or to the south, it would be a horribly, hot dry spell here that the models were foretelling.


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.