Catalina, Florida, USA

Dewpoints above dry ground yesterday of about 70 F at 3000 feet elelvation?  Yep, that’s just like Florida air if you could be in it at 3,000 feet.  And we had Florida-like clouds yesterday, too, with their warm bases, around 15 C (59 F) in the morning–remember how important warm bottoms are for a big rain dump. Warmer cloud bases mean more water up top.

After a couple of grizzily, grudgingly humid days with no rain very close by, we finally got that explosive, much greater coverage of huge Cumulonimbus clouds and some rain yesterday.  Only 0.06 inches here though.  Oh, well.  Lets be happy for well-watered others, if grudgingly.

The cloud signs that the day was going to be very different from the previous two humid “dry” days were there early. The first thunder was heard at 11:45 AM, as one cloud piled into the upper troposphere on top of Mt. Ms. Lemmon just an hour after the first photo below.  Those Lemmon drops produced 1.38 inches at the Pima County ALERT gage there, but a Summerhaven private gage reported 2.46 inches after several storms in the afternoon!

10:48 AM. The day ahead is laid out before you. No need to ponder whether giant storms will abound. Very tall, thin clouds like these tell you that the atmosphere is like a stick of dynamite; only the sunny fuse needs to be lit, and that fuse is beginning to be lit.  I was beside myself with excitement when several clouds like this jetted upward off the Catalinas yesterday morning, their “warm” bases topping the mountains.  As a cloud maven junior, you should have at least mentioned something to a neighbor:  “Man, there are going to be some doozies today!”, and he knows you haven’t even checked with the NWS yet.

Pima County rainfall table  Most:  Avra Valley area, Michigan and Calgary Streets, 2.13 inches.

Other rain totals here, from the U of AZ network.

Later yesterday day, these, a collection of my favorite moments, ones I hope you caught, too.  In case you forgot to log these events, I have filled in some appropriate “novella-sized” captions  for you. I don’t mind if you copy them down as though you had written them yourself… Also, don’t forget to review the awesome U of AZ time lapse movie here, to fill in any other gaps you might have.  Now these photos are going to be kind of scattered around but in that sense, reflect the writer’s eccentricities, and because he hasn’t got time to straighten them out.

11:20 AM. Your log book entry: “First cloud to reach glaciation level, 11:20 AM above Mt Lemmon. I am so excited. This is going to be a fantastic day for clouds.”
11:46 AM. Your log book entry: “First thunder now. The earlier Cumulonimbus capillatus cloud has been replaced by this larger one. I bet Lemmon/Summerhaven are getting pounded. Wish I could be there.”
12:31 PM. “Mt. Lemmon still getting pounded, but sky brightening, looks like the base has been eroded and is not being replaced, not good. Some rain working its way off Lemmon and Samaniego Ridge, but not making it very far. Maybe it won’t even get to me. Feeling sad.”
12:32 PM. “What that over there! I had not seen that while focusing on Ms. Lemmon. That cloud is huge. Look at that base, so firm, so fully packed! This is gonna be a great dump. I wonder if I can get over there in time. Nah, it goes too fast. Looks likes its gonna land on RailX Ranch over.”
12:38 PM six minutes later. “Oh yeah, baby, here it comes! Drops and hail as big as cataloupes! Well, I guess in Arizona, we would say, “as big as gourds!”, figuratively speaking.
12:41 PM, just THREE minutes later! “Feeling sad again that I am not there under this cloud with my raingauge. Maybe a cloud maven junior is there measuring it, keeping track of the time after getting his gage out in it, maybe see if some record for AZ is going to be set, like more than 2 inches in 15 minutes. I guess I can be happy thinking that someone is over there having a good time in the rain.”
12:54 PM. “Rain dump sweeping air out of the way like a big broom. Feeling a little exhausted now as storm reaches peak, likely to fade soon.”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In the meantime, more Cumulonimbus clouds form quickly over the Catalinas, but just as quickly fade, the rain getting closer, but only sprinkles have gotten to Catalina by late afternoon.  Then another surprise!

3:13 PM. “Yikes! What’s this coming around Pusch Ridge and out of Tucson? This is incredible-looking! Will set up video, charge camera batteries. No telling how much weather excitement might get to Catalina.”
3:33 PM. “Starting to look ‘biblical.’ That’s always good–‘the end is at hand’, at least of the disappointing dry days.’ I can only imagine how excited the cloud maven juniors are getting seeing this scene.”
3:40 PM. “The cool outflow wind has struck Sutherland Heights, those lower scud clouds riding on top of it. But where is the solid base needed for a regeneration of a huge dump of rain? I want really want to cuss and say, ‘dammitall’, but I will refrain from doing that. And its looking more stratiformy toward the south, like its dying out. What is happening? Is the main development going to propagate out toward Avra Valley again? Am really starting to feel awful now, that kind of disappointment you feel when your team has a 24 point lead at half time and loses by 12. Still looking ‘biblical’ but with your cloud maven junior skills you know its not looking ‘right’ for a big rain on you.”
4:05 PM “It is finished. ‘Biblical’ sky raced by, one associated with outflow winds of that really good storm somewhere else down to the south, and not on me, and it couldn’t push up some new fat bases of clouds that would grow into giant Cumulonimbus clouds as so often happens with the outflow winds. Going home now, kind of dejected. Hoping now we just get any measurable rain. Grasses fading in color now after our dry spell, and suggestion that a new season will soon be here, no more big clouds, adds to dejection and feelings of worthlessness. That’s what a disappointing day can do to you. But as Scarlet said, and we must remember those words, ‘Tomorrow is another day.’ And, we are having some lightning to the west of us here at 4-5 AM. Cool! Getting excited!”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Today?

OK, have spent some silly time here, now, looking out window, bases low on the Catalinas again. Dewpoints very high. Seems like it should erupt again IF the atmos structure above these clouds is anywhere close to yesterday. Let’s see what the best, Bob, has to say here. Oops, he’s not up yet, but he is the true guru of Cumulonimbus and such that we have here.  Be sure to check back soon!

Sounding from TUS this morning makes it look like its a “go” for giant clouds again, bases as warm as yesterday, if not a little warmer.  Egad, flash flood size.

Finally, U of AZ late night model here also says there’ll be a big day.  Charge camera batteries.

 

The End, finally.

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.