Looking for rain in all the wrong places…like here in Catalina

Another dry day yesterday, a tough one to take, since it appeared that rain hereabouts was a virtual certainty. All the model runs I saw from the U of AZ had good rains at times on the Catalinas yesterday afternoon and into the evening, as they do again for today.  Here’s one U of A model output for 2 PM yesterday (WRF Surface (Flash Animation) as an example.

So, when the dense Altocumulus clouds with their spotty sprinkles and light showers finally thinned and the sun burst forth in the afternoon, up went the Cumulonimbus clouds within the hour off in the distance from Catalina to the NE and SE.  It was going to be a great afternoon and evening I thought.  Tucson International AP reported lightning, thunder, off and on yesterday until after midnight, and even a few drops! Go here if you want to see all of last night’s action in the satellite and radar imagery from IPS Meteostar.

But none here.  Check the radar-derived precip from Intellicast.com.  You can see light rain was all around Catalina, dang.

Rainfall for the 24 h period ending at 5 AM AST today.

Cumulus started to form above Ms. Lemmon, and it seemed one of those was bound to explode upward as well.  While a brief sprinkle/virga fell out of one of those clouds at one point when it reached the “Cumulonimbus mediocris” stage, one  I made up, no full eruption occurred.  It was incredible that didn’t happen,  and so discouraging when you claim to be a Cloud-Maven, one who is supposed to know stuff.

The full discouraging day can be seen here, if you can stand to review it.  Still, these films are pretty interesting no matter what happens when clouds are present.

By evening all Catalina threats were seemingly gone, with no promising, massive clouds approaching from the northeast as they often do here at that time of day in the summer, rolling down out of the White Mountains, blackening the sky behind Charoleau Gap.  I missed a great sunset, too.

About today, in view of my poor track record, you might want to check out what Bob has to say.  He is one of the premiere scientists in convection, and lives right here in Tucson!  I think he has better graphics, too.  Also, here is the forecast from our NWS for Catalina, better get that in there for more balance, and maybe more accuracy!  They think the chance of measurable rain today in Catlina is but 10%.

However, being indefatigable, imperturbable, immutable, stubborn, I will press on with this forecast space:  _____________________ (write in your own forecast; it will likely be better than mine).  PS:  I think it will rain today.

BTW, even the coarse (as in grid spacing) Nvironment Canada model has a wet Arizona week ahead.  So, if not today, tomorrow!

Below, a photo reprise of yesterday.

6:59 AM. That promising morning sky. Light showers can be seen beyond the Tortolita Mountains.
1:25 PM. As the Altocumulus clouds faded, large Cumulonimbus anvils began appearing in the distance. This was going to be a great day.
1:41 PM. Mountainous Cumulonimbus tops rise up over the White Mountains to the NE!
1:26 PM. Cumulus are beginning to pile up over Ms. Lemmon! Surely there will be a giant Cb in an hour or two!
Later that day…. a painful sight.

 

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.