Sun pillar – Cloud-maven

Phenomenological extravaganza

First you had the rarely seen “Aircraft Produced Ice Particles” (APIPs, or “High Temperature Aircraft Contrails” (HTACs) in supercooled Altocumulus in the afternoon. Contrails were being produced in clouds that were “only” -20 C to -30 C (-4 to -22 F) and aircraft contrails were thought to be impossible at those temperatures, but rather, only at much lower ones, below -40 C (-40 F) or so.

Then, just after sunset, the heavy layer of Altocumulus produced a sun pillar! I was out in Saddlebrooke having dinner with friends after sunset, so had to leave dinner for about ten minutes, but I was so excited for you that I had to see it for myself, too. Since it would have been obscenely rude to tell my dinner friends the true reason why I left, when I got back after many minutes I told them I had to pee, and that seemed to go over pretty well I thought¹.

Below, a coupla shots of that sun pillar I got while “peeing” on your behalf:

5:33 PM Gently falling pristine² hexagonal plate ice crystals, falling face down from mostly supercooled Altocumulus clouds, produce a sun pillar. This site says that sun pillars are typically seen with Cirrostratus clouds and I have not photographed ONE due to Cirrostratus clouds myself, but rather ones like this falling from……yes, that’s right, Altocumulus clouds having just a bit of ice in them. How funny is that?

5:33 PM. Closer look as it fades. Note the small liquid water mammatus bubbles upper right. Mammatus in liquid clouds is also pretty rare since they are downward moving puffs of air and droplets evaporate much faster than do ice crystals. Mammatus is nearly always restricted to ice clouds for this reason. Was also wondering if my oversize salad and hamburger had been served yet.

Let us look at our sounding and see if we can see how cold those Altocumulus clouds were:

Tucson sounding launched from our U of AZ around 3:30 PM yesterday. The arrows denote the likely heights and temperatures of the Altocumulus we saw, somewhere around -20 C or -30 C or both. — Tucson sounding launched from our U of AZ around 3:30 PM yesterday. The arrows denote the likely heights and temperatures of the Altocumulus we saw, somewhere around -20 C (-4 F) or -30 C (-22 F) for both. Hard to tell which layer was the one the aircraft were flying in, but the colder the supercooled cloud the denser the ice trail. So…..since they were dense yesterday, CM is going with the one at -30 C. Yes, that’s right, liquid droplet clouds can exist at -30 C, full reasons not known, but indicates a lack of ice-forming particles up there. But, it can also happen at the ground, too, in fogs.

Here are some of the magical, rare scenes from aircraft making ice canals in those very cold supercooled Altocumulus clouds:

2:25 PM. Ice canal over Boot Barn. — 2:25 PM. Ice canal over Boot Barn down there on Oracle somewhere.

2:29 PM. Contrail castellanus? Had never seen anything quite like this before. Going crzy over sky phenomena now. — 2:29 PM. Contrail castellanus (that row above the pole)? Had never seen anything quite like this before. Going crazy over sky phenomena now. Word Press, as here, is corrupting some of these images; can’t fix it so far.

3:51 PM. Just above corrupted part of this file–I’ve given up trying to fix it in WP, is an aircraft streaking through this Cirrocumulus/Altocumulus deck, and an ice trail will form. How can you tell that that aircraft is IN the cloud and not above it? Look for different movement between the contrail and the cloud. If they are moving together, its usually the case that the aircraft was in the cloud. The aircraft is in the cloud at left.

3:51 PM Close up. Very excited that a trail would develop. You almost never see the aircraft leaving the trail like this; you see the trail after the aircraft is long gone.

Skipping to the chase, as hard as that is to do, this trail really lit up as it got to the 22 degree point from the sun, where mock suns and such happen, producing a rainbow of colors due to iridescence, a rainbow producing by very tiny ice crystals in this case, of the order of a few microns in size.

3:55 PM. Started to glow a little orange here.

3:55 PM. Was turning brighter colors as the seconds went by. Unfortunately, this image is again corrupted when bringing it into WP. — 3:55 PM. Close up of the feature event. Was turning brighter colors as the seconds went by

Still 3:55 PM. Going from orange to blueish.

STLL 3:55 PM. Color fades into white as this icy contrail in the Altocumulus raced eastward. More WP corruption here, too. Think I’ll quit! Just too much time to do this to have this kind of crap happen! Sorry, having little baby tantrum now.

Guess about today’s clouds

Maybe a few Cirrus, patch or two of Cirrocumulus, and likely lenticular clouds, particularly off to the north.

The End

The big storm everyone’s talking about?

Oh, yeah, baby, its still comin’, begins on Wednesday, New Year’s Eve in the afternoon, continues for about 24 h off and on.

Bracketing possible precip totals: still 0.25 inches on the bottom (10% chance of less), 1.50 inches on the top (10% chance of more). Average of those two often brings the best estimate, which would be about 0.87 inches, somewhere in there. You know, when you deal with wobbly cut off lows, you just can’t be real confident in how much rain they’ll bring. However, it looks like the north part of the State will get the brunt in snow, which will be great for the water situation.

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¹It would be fun to hear what your excuses were as a “CMJ”–Cloud Maven Junior, if you were in a similar predicament last evening and HAD to see that rare sun pillar, rather than meet new people at dinner who wouldn’t be able to understand you anyway because you are compulsed like that; leave a great dinner to go outside in cold air to take cloud photos.

Well, nobody really understands a CM.

I remember in grammar school and Junior High in Reseda, CA, when kids teased me on clear days , saying, “Hey, Artie! Is it gonna rain today?” Then they would laugh at me for being a CM before I even answered the question, knowing all the while what the answer was going to be. Still, out of civility, I would answer them: “No, we’re having Santa Ana conditions now and it can’t rain for at least five days”, but they would still be laughing in the midst of my explanation about why it wasn’t going to rain. Kind of a sad scene when you think about it, that is, how mean kids can be to kids who are different. Later, when I became a pretty good athlete, they liked me, which shows how important athletics is over knowing stuff, and helping you “fit in.”

²“Pristine” means that can’t be gunked up by having collected cloud droplets on their faces because then the optics, like sun pillars, mock suns, that kind of thing can’t happen if the crystals are messed up with droplets on them or a lot of extra hexagonal arms sticking out of them, as in bullet rosette ice crystals.

Interesting optics yesterday; substantial rains just ahead

Pretty boring lately…. No motivation here, even after caffeinating royally every morning. Have had some pro work to work on, too, like reviewing a manuscript for a journal–loosely translated, work that’s largely comprised of “finding fault in the work of others,” which I am pretty good at, to be a little immodest. Due this weekend, too…

11 PM U of AZ mod has late afternoon and evening rains in Catalina! Yay. Looks pretty wet, too, through the middle of next week, some lucky places (Catalina/Oro Valley) might get 1-3 inches during that time I suspect. (Neck out pretty far here.)

But…another longish dry spell takes hold after that. Seems to be the character of our summer; a couple good, wet days, then a long dry spell.

Still there were some great cloud sights yesterday, and I wanted to share them with my reader, wherever you are.

Down at second from the bottom is the rare sun pillar, and the last photo, a kind of an odd parhelia (sun dog) since the clouds were mainly Altocumulus ones in which it was occurring and it was darn bright.

Parhelia normally occur in icy Altostratus clouds. I would guess that this one might have been caused by ice crystals produced by an aircraft that passed through that Ac layer toward the horizon, right.

The End, back to work….

Lightning shows up, but not the rain

Another “awesome” display of lightning flashed over the Cat Mountains east of Catalina early last evening, accompanied by gusty northerly winds, but that fierce thunderstorm couldn’t make it over those mountains, but rather died on the way. Only sprinkles occurred here, giving us yet another “trace” of rain day. Kind of discouraging after the prior night’s nice little rain of 0.18 inches, one that also occurred after night fall. But as we know, weather never repeats itself exactly.

———-Yesterday’s major cloud mystery———–

Many of you, I am sure noticed the remarkable cloud scene below, perhaps as you came out of the house, or during your lunch hour, and likely puzzled over it the rest of the day. I, too, wondered how that little dot of cloud got so separated from its early Mt. Lemmon spawning grounds and brothers and sisters hovering over the mountain, trying to grow up. Notice that it seems like a puff of cloud, ragged on the bottom, a little rounder on the top. Could it be the top of a “smokestack” Cumulus that somehow we missed, whose connecting parts to Mt. Lemmon have evaporated? Its an important question that we shall try to answer.

12:51 PM. Cumulus humilis and fractus begin gathering over Mt. Lemmon. Recall, btw, this scene began a little after 8 AM on the thundery day before, for perspective--we're late, not a good sign. But what in the world is that little cloud dot to the left and middle of the photo? — 12:51 PM. Cumulus humilis and fractus begin gathering over Mt. Lemmon. Recall, btw, that this kind of cloud scene began a little after 8 AM on the thundery day before, for perspective–we’re late here, not a good sign of active rain day.)

To solve this mystery, Mr. (he’s not a doctor, nor does he have an advanced degree of any kind!) Cloud Maven Person went to the U of Arizona Department of Atmospheric Meteorology and looked at yesterday’s cloud movie. These are top rated movies, and, if you’ve ever looked at them, you can understand why clouds and what the weather does can be hard to predict; locations of storms missed, etc. No computer model can see all the remarkable little cloud wiggles, sudden comings and goings, that you see in these movies, thus introducing slight errors that tend to degrade those model predictions over time. And lots of the time, the locations of the clouds at the outset of the model run is even markedly off! Below, yesterday’s complex cloud movie linked for you in the word, “Movie”:

Movie

You will barely be able to read the time of the day in the lower left hand corner, which adds further complexity in solving this problem, but if you look closely you will see that a minute or two BEFORE the shot above at 12:51 PM, and slender tower rose up from Ms. Lemmon, its trunk evaporating almost immediately, but the last thing to evaporate was the little puff above that sped westward toward Samaniego Ridge.

In conclusion, I think we have solved yesterday’s cloud mystery.

——————-end of cloud mystery module——————–

That such a cloud could shoot up and out from Mt. Lemmon like this one did was a sign that there was great environment for much larger clouds, at least in the fall of the temperature with height (lapse rate), but that more humidity was needed to keep them from evaporating as they tried to grow. It wasn’t long before the hopeful sign of a Cumulonimbus calvus (anvil not formed yet) appeared beyond the Catalina Mountains, and the chance of evening rains, as the models had predicted, began to look better.

2:05 PM. Cumulonimbus calvus top makes its appearance, likely 70 miles or more away. — 2:05 PM. Cumulonimbus calvus top makes its appearance to the SE, likely 70 miles or more, and hours away.

5:33 PM. Threatening clouds and thunderheads were now moving into the Oracle/Mammoth areas, and the chances of a significant rain here were growing by the minute as major radar echoes approached from the east. I remember thinking how how happy I was that such a dreadful Cumulus day over the Catalinas was now going to be reversed by this onslaught of storms as the U of AZ model had predicted.

7:05 PM. Thus far, only "debris" clouds from the thunderstorms upwind had crossed the Catalinas, spreading westward toward the setting sun. But those dark clouds did provide the contrast as the setting sun lit up the Catalinas for this great scene. — 7:05 PM. Thus far, only “debris” clouds from the thunderstorms upwind had crossed the Catalinas, spreading westward toward the setting sun. But those dark clouds did provide the contrast as the setting sun lit up the Catalinas for this great scene.

7:22 PM. Multiple layers of clouds provide multiple sunset colors.

7:32 PM. That extra brightness in the center of the photo, if you noticed it, is called a sun pillar. Its due to a fall of plate-like, hexagonal ice crystals that fall face down that allow the sun's light to be reflected toward us. — 7:32 PM. That extra brightness in the center of the photo, if you noticed it, is called a “sun pillar”. Its due to a fall of plate-like, hexagonal ice crystals that fall face down and that enhances the reflected toward us. The sun set exactly below this bright spot. For a bit more on sun pillars, go here.

What seems to be ahead…..

The U of AZ mod hasn’t been updated as of this hour….so, being in a hurry, we’ll do an “SOP” forecast (you have to see Bob for a good one. I like Bob, too) but we have plenty of lower level humidity, and there appears to be a weak upper trough passing over us today, and that “should” help to collect storms into larger masses instead of just isolated ones. Oops, let me not forget our TUS NWS computer forecast for the Catalina area, too.

So, today might be the last day for a reasonably good chance of a major rain here in Catalina. After today, and for the next two weeks, the circulation pattern is not so great for summer storms, according to the NOAA spaghetti factory plots, seen here.

It seems more and more like we’re doomed to a drier than normal summer, darn it. (Missed those first great storms, too, that started our summer rain season.)

That’s about it for my cloud world. Camera will be ready for the black shafts of summer today!

Pillar of the sun

At sunset yesterday, this rarely seen optical display called a “sun pillar”:

6:58 PM. A sun pillar sprouted from the horizon due to a few plate-like ice crystals falling from those Altocumulus clouds.

Waited for a cute bird or bat to fly above or through the pillar, making it a more popular, valuable photo; instead a helicopter came by. But it “works” as shown below. You’ll have to look hard, but its there.

also at 6:58 PM. "Sun pillar with helicopter" $975. — Also at 6:58 PM. “Sun pillar with helicopter” $975. But, if you call now, you’ll get TWO of these exact same photos for $1,950.

Some of yesterday’s other interesting cloud formations:

4:25 PM. Patch of CIrrus spissatus with flanking CIrrus uncinus. — 4:25 PM. Patch of CIrrus spissatus with flanking Cirrus uncinus.

5:30 PM. CIrrocumulus (left side, fine granulation) and Altocumulus (larger more separated elements) right side. The whitish veil to the left of these droplet clouds are ice crystals. — 5:30 PM. CIrrocumulus (center, left, fine granulation) and Altocumulus (larger more separated elements) right side. The whitish veil to the left of these droplet clouds are ice crystals that likely formed within them.

6:38 PM. The fine and extremely delicate patterns in Cirrocumulus clouds still amaze.

Today’s clouds

Weak wave/trough passing to the south of us has some great middle and high clouds in it, splotchy ones that are sometimes incredibly spectacular, clouds like Altocumulus castellanus/floccus with virga. Just looked outside now and some of those are to the southwest of us at 5:35 AM. You can see how complex the cloud coverage is at IPS MeteoStar’s sat-radar loop here. They’ll be gone later today so enjoy them while they’re here.

The Weather Ahead

There are many troughs foretold for the Southwest and Great Basin area over the next two weeks. That the good news; it also goes with long term climo patterns that troughs like to nest in the Great Basin. But none extrude far enough southward, that is, the jet stream racing around the trough bottoms does not reach us, to bring precip to southern Arizona. Occasionally precip hits northern Arizona over this two week period, which is good, of course, for them and water supplies. In fact, its not even likely that we’ll see a cloud below 10,000 feet above ground level here if this pattern holds. And with troughs and low pressure centers nearby to the north, periods of windiness and dust will occur as they go by.

Fortunately, I guess, there’s little confidence indicated in these forecasts beyond about 11 days, NOAA spaghetti says, and so there are surprises that can pop up yet.

The End.