A last WY rain adds to total; 0.17 inches in violent, short-lived morning storm

Our WY total has crested over 11 inches now.  Its at 11.08 inches for the water year ending on September 30th, still about 5.5 inches below normal with only dry days ahead.  Still it was nice to see a great thundersquall come through on the last day of the summer regime, though I was about 12 miles away from Catalina when it hit.  So, I missed the last summer-type rain of the season with its momentary blinding rain and 40 mph winds; I had to be told about it.  That season will be just a memory now.

If you’re a reader of this blog, and I know who both of you are, you MAY recall that yesterday, off-handedly really, it was written here that, “I don’t think it will rain today.”  But it did rain, which is pretty remarkable in itself.  It has previously seemed that if I think or say something, that’s what happens, almost like  a supernatural connection of some kind with the future.  Some of the astrologers out there know what I am talking about, maybe palm readers, too.

I will go through what happened just that bit, well, quite a bit, while I display some photos and our thinking was about what we were seeing. I know that our thinking would be exactly the same since you read this so much.

Now, when I started yesterday morning on this blog, the dewpoints were very high around here, 60s, and there was a little line of clouds in the satellite imagery on our doorstep to the west.  Part of that north-south oriented cloud line is what you saw when you got up yesterday morning.

However, the dry air was already into central Arizona, with dewpoints in the 40s at PHX and Yuma; it was coming fast as the trough above scooted over us dragging a cool front.  Behind the cool front would be the dry air.

So what are you and me looking for when we think an LL Cool Front is approaching, along with its wind shift?

A line of clouds, solid, broken or even scattered.  So, when you saw that line of heavy Cumulus piling up in a line, SW to NW from Catalina, you and me were both thinking, “Droop, there it is!1“, to recall a song first heard on the TEEVEE show, “In Living Color.”

8:26 AM. Front on the doorstep or not.
8:26 AM. Front on the doorstep or not.  Looking west toward the Tortolitas.  Even though the clouds are piled high, notice that there are NO rain shafts.  No ice, and even with the warm bases at about 10 C (50 F), rain from drop collisions with each other also did not form.  See smog shots later; smog is an impediment to that process.

 

8:24 AM. Heavy Cu line extends off to the N as well, strongly suggesting a wind shift is causing it.
8:24 AM. Heavy Cu line extends off to the N as well, strongly suggesting a wind shift is causing it.  Again, no rain shafts are seen from these large clouds.
8:20 AM. While the sights to the west were promising, the amount of smog (not dust here) was deafening. Sure there were pretty highlights as the crepuscular rays focused on our still green mountains, but still, its not a good sign for precip; works against it.
8:20 AM. While the sights to the west were promising, the amount of smog (not dust here) was deafening. Sure there were pretty highlights as the crepuscular rays focused on our still green mountains, but still, its not a good sign for precip; works against it by causing the drops in clouds to be smaller than they would be in “clean” conditions.
8:38 AM. Eventually those tops did reach ice-forming levels, those likely colder than -5 to -10 C yesterday, and rain shafts began to emerge, as here. But, that was off to the north beyond SBrooke, and the clouds to the SW of us were turning ragged, drying out.
8:38 AM. Eventually those tops did reach ice-forming levels, those likely colder than -5 to -10 C yesterday, and rain shafts began to emerge, as here. But, that was off to the north beyond S-Brooke, and the clouds to the SW of us were turning ragged, drying out.
9:06 AM. By 9 AM, any hope for rain here had seemingly vanished as the clear signs of dry air moving in, along with subsidence aloft were clear. It hadn't rained, and though I always hope it will, I was amazed at how my risky forecast of no rain had magically occurred, leading to a slight case of megalomania, grandiosity, if you will. It was though I had spoken those smoggy clouds directly. It was finished. I now thought I might as well leave and go on some errands; not chance of rain now!
9:06 AM. By 9 AM, any hope for rain here had seemingly vanished as the clear signs of dry air moving in, along with subsidence aloft,  were now clear to you and me. It hadn’t rained, and though I always hope it will, I was amazed at how my risky forecast of “no rain” had magically occurred, leading to a slight case of megalomania, grandiosity, if you will. It was though I had spoken to those smoggy clouds directly. It was finished. I  thought I might as well leave and go on some errands; no chance of rain now!  I also think of myself as kind of a Garrison Keillor of clouds, tellling stories about them, and continuing a megalomaniacal theme here.   “I try to tell the truth”, Garrison once said, then continuing,  “but the truth doesn’t always take you as far as you need to go.”
SONY DSC
9:03 AM. Looking NW. Those huge clouds of just a few minutes earlier are gone, and now only suppressed versions of Cu are seen.

Then, the transformation back to what we had just seen earlier that morning!  It was amazing, with HUGE Cumulonimbus clouds arising from the same appearing line of heavy Cu.  Here we go into “error”, and I would add, humility:

9:49 AM. Was in route to Marana. Though these Cu had fattened up from nothing, thought they would be dessicated by the dry air moving in, would ragged and shredded looking in the middle and upper portions.
9:49 AM. Was in route to Marana at this time from SH, but stopped to take a photo. Though these Cu had fattened up from nothing, thought they would be dessicated by the dry air moving in, that is, would look ragged and shredded and not amount to anything.
10:14 AM. WHAT? A shocking view, this Cb and rain shaft, upwind of Catalina. I had to keep going to finish an errand though, not race back and enjoy what MIGHT be the last storm of the summer rain season.
10:14 AM. What?  This was a shocking view, this Cb and rain shaft, upwind of Catalina. I still had to keep going to finish an errand though; not race back and enjoy what could be the last storm of the summer rain season.
11:15 AM. Your storm, about to strike. Those clouds on this side of the giant, mounding Cb were the ones that done it, ones that exploded upward a few minutes later.
11:15 AM. Your storm, about to strike. Those clouds on this side of the giant, mounding Cb were the ones that done it, ones that exploded upward a few minutes later.  Fortunately, I got some first hand reports from neighbors and used some imagination to experience how bad it was for a few minutes.
11:57 AM. Just back in SH country, and the showers are still around, here to the NW.
11:57 AM. Just back in SH country, and the showers are still around, here to the NW.
11:58 AM. But this view to the SW and upwind, is really The End, its over, it is finished, etc. The summer rain season has ended for us. The dry is moving in now, the clouds will wither and die even as the afternoon warms up some.
11:58 AM. But this view to the SW and upwind, is really The End, its over, it is finished, etc. The summer rain season has ended for us. The dry is moving in now, the clouds will wither and die even as the afternoon warms up some.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The only weather ahead now for the next couple of weeks is temperature changes.  That’s about it, so will take a little break here, maybe only post once in awhile, and more on climo or science stuff.

The End.

 

 

 

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1Modified for baseball to, “Bloop, der it is!”. A “bloop” is a weakly hit ball that falls for a base hit.

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.