Raining hard here at 4:08 AM

Little cell going by (aka, weak Cumulonimbus).  I hope you’re up to enjoy the sounds of a good cellular rain on the roof.  I feel like another song coming on.  Ooops, same one, but its a good one because it not only has rain and thunder in it, but also pathos1.  (I thought the thunder in this song gave it a lot of dramatic impact, and we had some thunder NE of Saddlebrooke yesterday afternoon around 2:45 PM.)

Cell has added 0.03 inches to our 0.13 inches and this morning’s total is now a quite nice 0.16 inches on top of the 0.30 we got yesterday.  Raining harder now after it let up!  Oh, that didn’t last long.  Dang.

Total here at 6:55 AM: 0.18 inches!  Two day total here, 0.48 inches.

This is so great since this second part of this two part storm was “marginal” as a rain producer, might have only produced 0.05 inches as the bottom estimate for rain, made a few months ago (just kidding), with a top possible amount of      0. 40 inches.  So, we’re getting close to the middle of the prediction range made so long ago, 0.225 inches, a prediction you may remember, one that was based on spaghetti.

This rain is associated with the strong cold front that passed through Catalinaland about 2 AM, just after those strong gusts occurred, 30-40 mph last night.   Here’s what the nighttime temperature did, drop 14 degrees!

And, as you no doubt know, the atmosphere pressure goes up instantly as the cold front goes by and the colder heavier air piles on top of you. (Time hacks don’t match on these charts for some reason–have not noticed that before….)

Arrow points to passage of cold front at Catalina, AZ.
Atmospheric pressure on top of you here in Catalina, AZ. Arrow denotes cold front and rise. With this denser air, you may notice that you’re having difficulty getting up, moving around as you push more “molecules” of air around for any given movement compared with yesterday when the air was not so dense. It also might be because you have more clothes on today…. Hahahaha

Here’s a really nice link to radar happenings locally from The Weather “Underground” (nothing to do, BTW,  with “The Weathermen” of the 1960s-70s even though it sounds like it).

Learning module….skip if bored already.


One of the things that is happening right now at 5:01 AM LST, is that cells are appearing on the radar or intensifying as they move toward Catalina.  This happens a lot when the air at cloud height is moving toward the Catalinas and upslope toward Oracle and Mammoth, getting squeezed between the Tortolita Mountains and the Catalinas.  That lifting  makes the tops go up to higher colder levels, and when the tops to the west and southwest are too warm for ice formation, say above -10 C (14 F), then just a bit of lifting triggers ice formation making a cloud “visible” on radar as the ice grows in size into snowflakes, maybe collides, too, with some itty bitty cloud droplets (too small to be seen by radar) growing even larger and falling faster.  This is maybe the biggest reason why Catalina has so much more rain than upwind areas (17 inches annual rain) compared with about 11-12 inches upwind.  Most of that difference comes in the wintertime in situations like this, and so some extent, like yesterday’s more general rains.


What’s ahead for today?

Back edge of this rain band, more or less solid clouds dotted with deeper ones producing rain, is on the doorstep.

Here it is as of 4:45 AM from the U of AZ Weather Department Satellite Facility, with a CONSIDERABLE amount of arrows and writing on it:

So, according to this “diagram” the back edge of this band on the sat image should be here by no later than 10 AM today, that is, chance of additional rain up until around 10 AM in a brief shower, but only a hundredth or two likely.  After that, just clouds, probably a lofted Stratocumulus layer, then a widespread clearing with scattered to occasionally broken Cumulus.

Since it is so cold aloft now with the freezing level around 5,500 feet (snow shower now (7:29 AM) on Samaniego Ridge), ice will like form even in modest Cumulus clouds this afternoon, that means virga or maybe an ISOLATED light rain shower possible through around dusk.

Yesterday’s clouds

Here are some of the best cloud photos from yesterday, such a pretty day here in Catalina, where Cumulonimbus clouds stayed just to the north of us off and on all day.

1:19 PM. Cumulus congestus/Cumulonimbus with a young turret on the left that has not yet glaciated (though there is ice inside without doubt) and an older turret that one on the right that is completely ice.
2:31 PM. Cumulus mediocris/congestus over the Catalinas.
2:44 PM. This Cumulonimbus with a graupel shaft produced one roll of thunder.










5:24 PM, dessert. Some remaining Cu bottoms turn gold in setting sunlight. On the horizon, the frontal cloud band.









The End, at last!


1Actually, I made it sound like I wrote this song in yesterday’s blog, but in fact, I did not, though I WOULD have if I had thought of it.  Note that the person who uploaded this song to You Tube, did not know how to spell, “Cascades.”  No wonder we’re falling behind.