Day of early and late storms

First, the rain report:  1.73 inches on Samaniego Ridge in the 24 h ending at 3 AM this morning; 0.42 inches here!  Fantastic.  We’ll keep those watery, glistening rocks on the sides of the Catalinas for a few more days.  How nice is that for mid-September?   Some rain 24 h totals til 3 AM, catches the early yesterday storm period from some of the Pima County ALERT rain gages (a bit chopped up, sorry):

Today?  Lots of incoming stuff, should be another day of major rains!  (Maybe our last of the summer season.  Enjoy.)

 


Reviewing yesterday…..

Looks like afternoon but its not; yesterday morning just after dawn:

6:33 AM. Unusual early morning thunderstorm rakes Catalinas. What a great scene for dawn.
6:39 AM.

 

 

 

 

 

 

 

Later that afternoon, after the morning Altocumulus clouds thinned and skies became sunny, there was explosive cloud growth over the Catalinas as the temperature recovered from our pre-dawn rains and clouds.  Below,  a few shots, the first three showing the transition from Cumulus congestus clouds lacking in ?????? (Answer:  ice), to ones just starting to show ice in their tops (which means snow and then rain formation).

Now I am going to transition to tiny thumbnails, so you’ll have to work harder to see what I am talking about.  But if you work hard, you might remember it better.  Also, to help you, I have added an arrow in one shot, really going that extra mile for you today since usually I am too lazy to do that.

The Cumulus congestus clouds you see in the first couple of photos, though quite pretty, are oriented ALONG the Catalinas, not trailing over us from Mt. Ms. Lemmon.  This tells you that should rain develop in these clouds over the Catalinas later on will stay ALONG the Catalinas, and not dribble over this way as it often does.   That means incoming storms for us here in Catalina will be to the south, toward Pusch Ridge.  Still pretty much the same today, except a bit more toward the right of Pusch Ridge, and toward Twin Peaks.

Below, another example of a cloud photo diary, pretty much like the one you should be keeping:

2:07 PM. After a weak shower around noon, Cumulus congestus rebuild over the Catalinas and kind of just mill around for awhile not doing much, being less than they could be.
2:15 PM. Its EIGHT minutes later, and I am getting pretty impatient with these clouds. Sure, they’re looking pretty, but they have nothing in them so far (except droplets).
2:24 PM. FINALLY, after being bored by pretty but empty Cumulus congestus clouds with nothing much up top, ICE forms (arrow)!

 

 

 

 

 

 

 

 

 

2:34 PM. Had to wait another TEN minutes for some “content” to show up below this cloud, that fine haze of rain just appearing at the top of Sam Ridge in this photo. Note all the ice/rain trails just above the bottom. Time to think about lightning, too, some real content!
2:46 PM. First transition to a Cumulonimbus and a thunderstorm, now maybe two rumbles old, is a weak one, shown by the weak shaft on the left. But what’s that coming out of that base to the right?! Now that’s more like! That far denser shaft on the right shows that the upwind turret has powered upward FAR higher than the one topping the weak thunderstorm. This is gonna be good!
4:06 PM.  And so it was good. This, one of several outstanding rainshafts that affected Sam Ridge and helped that 1.73 inches total along. No doubt something even a bit higher went unrecorded. Here you can also see the end of the heaviest rain blob about halfway down from the cloud base indicating the original turret up top has dropped all it can and will be dissipating.

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.