Rain: its out of mind, but not out of sight

The summer rain season has departed from us here in Catalina, but its still evident on the horizon in Mexico, and even here in Arizona.  Take a look at these distant Cumulonimbus cloud tops yesterday.

4:59 PM. Arrows denote Cumulonimbus tops protruding from anvil Cirrus shield, “over the border, down Mexico way”,  as the song says.
7:00 PM. Looking WSW from Catalina at a massive Cumulonimbus top.

So, as we like to say around these parts, someone’s getting shafted (rain shafted, that is)

An example of conversational meteorology for everyday use:

Person 1: “Did you get shafted yesterday?”

Person 2:  “Yeah, it was GREAT! Got more than an inch in just over 30 minutes!”

End of example.

Looking a few days ahead

While we are dry now, the summer rains are really pretty close (as represented by green pixels in this rendering of the WRF-GFS model, our best one).

Unfortunately, it keeps the “green pixies” away until the afternoon of September 4th; Elena, our hope for rain just after the first, stays too far west now this mod says.

However, as close as the rain is day after day in this mod, even a slight model flub, a “fumble” really, in keeping with the emerging college football season,  could mean a random shower between now and the 4th.  That’s our only hope from that one.  But, to the rescue our Canadian friends and their model.  That model still drags a part of tropical storm Elena’s moisture into AZ with a couple of showers indicated around here on the 1st and 2nd of September.

Looking farther ahead at less reliable results:  green on green

The dry spell ends and a series of wet days are foreseen beginning on the 5th in SE AZ, and then spreading over various portions of the whole state (green pixels on the green of our State right now) from the 9th through the 14th in this same model.  I mention this only because it was also predicted from yesterday’s model run from global data taken at 5 AM LST.  Its not much to go on, but something.  An example for the afternoon of September 12th where so much rain is predicted the pixels have turned blue (see scale at bottom to interpret amounts).

Not so good is the fact that this later predicted rain is associated with rather weak flow patterns, ones that inherently degrade the model’s reliability.  So, don’t count on these rains, but it is there for now and has an itty bitty amount of credibility.  Namely, its not hopeless that we are done with our summer rain season, as we know,  can happen anytime now.

 

 

 

 

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.