Altocumulus clouds, Altostratus clouds, Cloud seeding, Cumulonimbus clouds, Cumulus clouds, Definitions, The weather WAY ahead (10 days or more)

Stratiform clouds bring steady rain and snow; sixteen hundredths to Catalina

“Sixteen hundredths”, originally a song by a boy group of that day so long ago, The Crests, about a light rain that fell in May in southern California, an event that is quite rare and exciting at that time of the year there.   But then practical and marketing considerations caused the song to be revised to one about candles of all things.  How odd.  I thought you might like to know some reliable history behind that venerable song, one that made us cry, it was so sweet, and think about, as boys, how much we liked girls when WE were sixteen or so.

Yesterday, while Mr. CMP (“cloud maven person”, but using acronym in trying to be as indirect as possible here) was making some fun of students mixing up units in their calculations of pressure at  various heights in the atmosphere, he himself was mixing up cloud “units”, by informing his reader that cumuliform clouds, some dropping graupel, would be seen over Catalina yesterday, not stratiform, sky-covering Altocumulus, followed by great masses of Stratocumulus underneath it, combining later with gray, dank, Altostratus, a scene that finally evolved in the mid-day hours into Nimbostratus with light rain, sometimes with light snow mixed in!  Briefly, too, it was ALL “surprise” snow!

The total, 0.16 inches, was also about sixteen times more than CMP thought would fall from that perceived marginal weather producer. (Note:  the U of AZ local model’s 11 PM run the night before had it predicted perfectly!  However, in some kind of bloated self-evaluation of skill levels, CMP did not consult that model until it was “too late.”)  Today, I am quite confident, however,  that I really don’t need to look at that model…

What is going on here? Fallibility, I calls it, human fallibility.  Remember that old saying about pencils with erasers at the end?  So simple and yet, profound.

Oh, well.  All’s well that ends well, and the “well” ending was one of a nice little rain mixed with snow (will burn your CMJ tee if you refer to rain mixed with snow as “sleet”!) and beautiful snow down on the Catalinas, so pretty yesterday evening as the clouds lifted.

Today a fine day with small Cumulus clouds, very photogenic again as this kind of wintertime day is here.   The mountains should be spectacular, too, due to the cold air that remains that will allow them to be white down low for a few hours this morning.

Pima County precip totals here.

Precip totals from the U of AZ rainlog.org network here and the national CoCoRahs org here for AZ totals.  The measrements at rainlog will indicate that they are for yesterday, the 11th, while the CoCoRahs convention, to assign the rain to the date it was reported,  will show the totals for our storm using today’s date, the 12th.  You’ll have to wait until about 8-10 AM to get most of the loggers’ reports.

The most I saw in the Pima County gage network was 0.43 inches, an amazing amount, down in Avra Valley.  Shocking, really.

BTW, the cloud regime that CMP foresaw for Catalinaland was just to the west of us, around Ajo, AZ, not that far away astronomically speaking.  And at sunset yesterday, you could see those Cumulonimbus clouds on the horizon coming into view.

5:53 PM. The forecasted Cumulonimbus clouds begin to come into view.
5:53 PM. The forecasted Cumulonimbus clouds for Catalina begin to come into view.  I wish I could make this image bigger, maybe in 3-D so you could “feel” this cloud coming at you.

To cry-baby about it a bit more about a missed cloud forecast, this “visible” wavelength satellite image:

1:45 PM AST.
1:45 PM AST.

Some un-Cumulus scenes from yesterday:

10:30 AM. Altocumulus perlucidus undulatus and Stratocumulus begin overspreading the sky.
10:30 AM. Altocumulus perlucidus undulatus and Stratocumulus begin overspreading the sky.
11:41 AM. Dark bases of Stratocumulus-Cumulus line up with the wind and head toward Catalina. Virga spews in the distance on the right.
11:41 AM. Dark bases of Stratocumulus-Cumulus line up with the wind and head toward Catalina. Virga spews in the distance on the right. Above these clouds was an icy layer of Altostratus.
11:58 PM. Mounding tops of Stratocumulus-embedded Cumulus become infected with ice and spew forth virga. Now under this guy, there may well have been a couple of graupel.
11:58 PM. Mounding tops of Stratocumulus or embedded Cumulus become infected with ice and spew forth virga. Now under this guy, there may well have been a couple of graupel. Above these clouds was an icy layer of Altostratus that helped impregnate the lower Stratocu and Cu with ice, kind of like seeding them.
1:17 PM. The lumpy and dark looking bases had disappeared in the virga and snow falling from the thickening Altostratus layer as it became, Nimbostratus. What you're looking at here is a classic example of snow melting into rain that appears to be the base of the cloud, but its really a transition zone that reveals the snow level.
1:17 PM. The lumpy and dark looking bases had disappeared in the virga and snow falling from the thickening Altostratus layer as it became, Nimbostratus. What you’re looking at here is a classic example of snow melting into rain that appears to be the base of the cloud, but its really a transition zone that reveals the snow level.
3:14 PM. Snowing hard in Catalina for a few minutes. Here's what it looks like, coming down at you. Some aggregates of snowflakes were more than an inch across.
3:14 PM. Snowing hard in Catalina for a few minutes. Here’s what it looks like, coming down at you. Some aggregates of snowflakes were more than an inch across.
5:42 PM. The result of our little storm on the Catalina Mountains, Samaniego Ridge.
5:42 PM. The result of our little storm on the Catalina Mountains, Samaniego Ridge.

The weather ahead into March

Gotta ride the storms, ones already predicted as of yesterday here over the latter half of this month. Never good to “yo-yo” on a forecast, as forecasters will tell you.

However, not getting help again in this longer range musing from the NOAA ensembles of spaghetti; site is still down, so riding bareback here so-to-speak, using a western idiom (or is it “idiot”?) In sum, Arizona to end up with above normal precip when whole state considered. This due to being in the bowl, the trough bowl, though breaks in storms, and nice weather, sometimes for several days at a time, will try to fool you into thinking you’re not.

Going farther out on a limb, twig, really, looks like the active storminess will continue well into March. We seem now to have a wet pattern going, though in a desert, its not THAT wet compared to Washington State or elsewhere. Stand by for occasional updates. Am excited for wildflowers now; there may be some!

The End.