Category Archives: Aircraft Produced Ice Particles

Looking ahead to May, and something about the new Int. Cloud Atlas

April’s been kind of a weather dud here in Catalina so far (no rain so far, and the chance on the 20th, mentioned here some weeks ago, has receded to Utah and points north), so lets take a look at how May is shaping up, only two weeks ahead:

 Valid at 5 PM, May 2nd. Nice!
Valid at 5 PM, May 2nd. Nice!

I thought you’d be pretty happy when you saw this, as I was.

 

BTW, there is a new International Cloud Atlas out there.

Its possible there is a photo from Catalina, Arizona!  I have not checked yet.  Its just been published by the World Meteorological Organization of the United Nations.  Still needs a little work, but overall is VERY, very nice.  Came out out on March 23rd, so we’re a little behind here as usual.  The thing that makes it different from prior and sometimes flawed atlases is that each photo is accompanied by some weather data and in many cases maps, radar or satellite imagery at the time of the photo.

Some new expressions to toss around to your fellow cloud-centric folk are things like “Cirrus anthrogenitus”–Cirrus evolved from contrails and “Cumulus flammogenitus”, a Cumulus formed at the top of a fire, something we used to call, “pyrocumulus”, an unofficial term that somehow seems preferable to “flammo”.

However, something that has drawn great attention over the past 20 years or so was not given a name, aircraft-produced ice in Altocumulus and Cirrocumulus clouds, which have been referred to by Heymsfield and colleagues as “hole punch clouds.”1

Hole punch clouds pdf

Ice canals amid Altocumulus are also fairly common.  Ironically, a hole punch cloud with ice in the center, and an ice canal in an Altocumulus cloud layer can be readily seen on the new International Cloud Atlas submission site, now closed.  They’ve mistakenly, IMO, referred to “ice canal” photos as “distrails” without mentioning the ice canal “cirrus” down the middle.  Formerly, distrails were clearings produced by aircraft in thin clouds without any change of phase in the cloud induced by the aircraft, unlike those holes and clearings produced when the ice-phase is triggered by an aircraft passage.

Certainly a “hole punch” cloud is not a distrail, a linear feature, and should have a separate nomenclature.

In keeping with the new terminology regarding “anthro” effects, maybe it should be, since we’re talking about the Cirrus induced by an aircraft, albeit at much lower levels than true Cirrus clouds:

“CIrrus Altocumuloanthroglaciogenitus.”  (??)

Here’s a classic one of those that erupted over Catalina, posted here last January:

11:27 AM, January 2nd. The ice canal in the middle of an Altocumulus layer that might in the future be termed a Cirrus altocumuloanthroglaciogenitus.
11:27 AM, January 2nd. The ice canal in the middle of an Altocumulus layer that might in the future be termed a Cirrus altocumuloanthroglaciogenitus.

 

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5:53 PM. An example of the various cirriform clouds we’ve been treated to the past week or two, ones that have been giving us those nice sunrises and sunsets. Doesn’t seem like there’s been a cloud below 50,000 feet for about that long, too. (I’m exaggerating just a little.)
7:04 PM. Seems like sunsets are occurring later and later.
7:04 PM. Seems like sunsets are occurring later and later.  Here the setting sun allows some of the “topography” of Cirrus clouds to be accentuated.

 

The End

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1It should be pointed out immediately if not sooner  that Catalina’s Cloud Maven Person had plenty of time to rectify, or suggest changes to the Atlas as he could have been part of this process, but didn’t really do anything except submit some images for consideration.

More patterns galore, but with natural holes in them that made for an extra fascinating day!

The TUS balloon sounding launched at around 3:30 PM from the Banner University of Arizona
The Banner NWS TUS balloon sounding launched at around 3:30 PM from the Banner University of Arizona.  The temperature of the Cirrocumulus was indicated to be about -36° C, at about 26,000 feet above Catalina (29,000 feet ASL) and yet portions of the Cc had liquid droplets.  The higher vellums of Cirrostratus or Cirrus were located.

Photos of yesterday’s patterns

I could literally hear the cameras clicking all over Catalina and Oro Valley as these patterns showed up, moving in from the southwest as the increasing numbers of cloud-centric folk lost control of themselves.  Reflecting that general loss of control, which affected yours truly, too many photos will be posted here.  Below holey clouds with icy centers, but not ones caused by aircraft:

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And look closely at the fine patterns, lines and granulations in these shots!  Truly mesmerizing.

DSC_3222 DSC_3221But what’s missing in this photo above?  There was no iridescence seen around the sun where we normally look for it suggesting that those Cirrocumulus clouds nearest the sun were composed of ice crystals, and not tiny droplets.    Iridescence is rarely seen next to the sun due to ice crystals because they are usually the result of the freezing of existing droplets, that then grow rapidly as ice particles to sizes too large to produce diffraction phenomenon  close to the sun.  Where’s my Lear jet,  so’s I can confirm these speculations?!!  I would very much like to have one on “stand by”, in case I think of something.  Below, a wonderful example of no iridescence even though newly formed clouds are by the sun:

4:21 PM. An outstanding example of no iridescence, maybe one of the best ever taken!
4:21 PM. An outstanding example of no iridescence, maybe one of the best ever taken!  The power pole shows signs of being in an archaic neighborhood.

A jet runs through it

Or so I thought.  In this chapter of cloud-maven.com, we inspect the photos of a commercial jet flying at or near the level of these clouds and determine what happened.  I was quite excited to see this happen because we would now determine whether there were any liquid droplets in what to the eye of the amateur cloud watching person would be a liquid droplet Altocumulus clouds.  Here the size of the elements are just a bit too large to lump it into the Cirrocumulus category, if you care.  So, with heart pounding, took this sequence of photos:

4:23 PM. A commercial jet streams into it seems, the Altocumulus layer. Or did it? CMP thought so.
4:23 PM. A commercial jet streams into it seems, the Altocumulus layer. Or did it? CMP thought so.

Let is go zooming:

4:23 PM. Looks to have descended to below this layer. Note sun glint on aircraft.
4:23 PM. Looks to have descended to below this layer. Note sun glint on aircraft.
4:23 PM. Zoomin' some more.
4:23 PM. Zoomin’ some more.
4:26 PM. But, as the location of the aircraft path slipped downwind rapidly, there was NOTHING! I could not believe it! No ice canal with a clearing around it, and no contrail inside these clouds. The clearing would have occurred had the aircraft penetrated supercooled droplets leaving an ice canal. But, if the cloud was all ice, a penetration by an aircraft should have left a contrail, as they do in cirriform clouds. The conclusion? As close to this layer as the aircraft was, it did NOT apparently go into it. Amazing to this eye.
4:26 PM. But, as the location of the aircraft path slipped downwind rapidly, there was NOTHING! I could not believe it! No ice canal with a clearing around it, and no contrail inside these clouds. The clearing would have occurred had the aircraft penetrated supercooled droplets leaving an ice canal. But, if the cloud was all ice, a penetration by an aircraft should have left a contrail, as they do in cirriform clouds. The conclusion? As close to this layer as the aircraft was, it did NOT apparently go into it. Amazing to this eye.
4:25 PM. Looking downwind at those "Altocumulo-cirrus" clouds, all ice from almost the very leading, upwind edge due to that -36°C temperature they were at.
4:25 PM. Looking downwind at those “Altocumulo-cirrus” clouds, all ice from almost the very leading, upwind edge due to that -36°C temperature they were at.  Though overhead, as you saw in the photos below, they might be reckoned as plain Altocumulus, and not solely composed of ice ones.

By the way, if you caught it, there were a couple of standard, aircraft-produced, “hole punch” clouds at the very upwind, formative portion of this patch of clouds before it got here. These photos pretty much prove that the Cc at the formative end at that time was composed of highly supercooled droplets and that the passage of an aircraft produced ice, that caused a fall out hole.

1:52 PM. Hole punches caused by aircraft in the Cirrocumulus to Cirrus patch that moved over us later. Clouds like these do not move at the speed of the wind, about 60mph up there yesterday at this level, but rather, the air moves through it a hump in the airflow that moves much more slowly than the wind.
1:52 PM. Hole punches caused by aircraft in the Cirrocumulus to Cirrus patch that moved over us later. Clouds like these do not move at the speed of the wind, about 60mph up there yesterday at this level, but rather, the air moves through it a hump in the airflow that moves much more slowly than the wind.  Note the slight iridescence in the hole on the right.

 

The End–quite enough, eh?

Some optical stuff; some holey stuff

Once again we had a brief period of optical fireworks, as a rare “circumzenithal arc” developed overhead of Catalina in some Cirrus strands.  Hope you saw it and bragged about it to your less observant friends.   After saying that, follow it up in a moment of feigned reflection,  speaking to no one in particular, with a comment about “how sad it is when people don’t notice the beauty in the world around them.”   Your friend will appreciate what a sensitive person you are.  That would be great!

Here are the scenes so many missed because you only have SECONDS to see them light up, peak out and disappear (but I saw it!):

9:28:31 AM. First highlight begins, center, leading edge.
9:28:31 AM. First highlight begins, center, leading edge.
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9:28:44 AM. Here we go!
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9:29:43 AM. Starting to really light up!
9:30 AM. Where were you? Of course, like a rainbow, you would have to be where I was to see this exact sight, but I was alone.
9:29:45 AM.  Zooming in….   Of course, like a rainbow, you would have to be exactly where I was to see this exact same sight, but I was alone and therefore, the only person in the world to see this.
9:30:29 AM. Last little wisp of color goes over.
9:30:29 AM. Last little wisp of color goes over.

Whew, that was pretty much the climax of this event.  Began to relax. calm down,  as the possibility of seeing more “arcs”, began to fade.  No more Cirrus was upwind.

Most of these I have seen have been due to aircraft-produced ice particles (“APIPs”, as named by Rangno and Hobbs way back in 1983, J. Appl. Meteor.), i. e., contrail like events produced by aircraft that occur at much higher than expected temperatures in “supercooled” clouds.

No Altocumulus clouds were around this line of Cirrus uncinus clouds at the time this passed over, though there were plenty around, however.  Likely this was produced upwind by an aircraft in Ac clouds, and the Altocumulus droplet clouds just evaporated.

These aircraft produced ice clouds start out having prodigious, unnaturally high concentrations of ice, thousands per liter, and that in itself would lead, due to the competition of vapor among them, to tiny, pristine ice crystals like solid columns that would refract the sun’s light.  So, that’s my thought on the origin of this line of Cirrus uncinus, the line itself raising suspicions about its origin.  It extended much farther than shown in these photos, and was intermittent, likely reflecting where the Altocu was, and where there were holes in the coverage.

Then, a great cloud iridescence:

11:03 AM.
11:03 AM.  Iridescence, about as good as it gets.
11:07 AM. Iridescence lights up a portion of an Altocumulus cloud.
11:07 AM. More iridescence.  Hope you saw this, too.

 

Next, holey stuff.

Never seen anything quite like what happened in those quasi-laminar clouds that developed later in the morning over and near the Catalinas, so must show :

11:08 AM.
11:08 AM.  Intrusions of dry air started punching holes in clouds all over.
11:09 AM. Holes started to appear in adjacent clouds.
11:09 AM. Holes started to appear in adjacent clouds.
11:09 AM. Zooming in at this strange phenomenon.
11:09 AM. Zooming in at this strange phenomenon.
11:11 AM. Geeminy Christmas, the sky is falling!
11:11 AM. Geeminy Christmas, the sky is falling!
11:12 AM. Closer to life size here. Pretty remarkable. Outside border of hole seemed to have collapsing cloud filaments supporting a localized downdraft punch.
11:12 AM. Closer to life size here. Pretty remarkable. Outside border of hole seemed to have collapsing cloud filaments supporting a localized downdraft punch.
11:12: More holes began to appear next to the main one.
11:12: More holes began to appear next to the main one.
11:14 AM. More hole craziness!
11:14 AM. More hole craziness!
11:15 AM. Wow. Look at the complexity in that hole.
11:15 AM. Wow. Look at the complexity in that hole.
11:17 AM. This lenticular had an exceptionally smooth top, but a hole started to develop underneath and a little downwind.
11:17 AM. This lenticular had an exceptionally smooth top, but a hole started to develop underneath and a little downwind.
11:17 AM. Another dry air hole punch appeared. What an interesting day this has been so far, and its not even noon!
11:17 AM. Another dry air hole punch appeared. What an interesting day this has been so far, and its not even noon!

 

Well, as you could imagine,  I could go on and on about this, with many more photos, but need to quit here.  And besides, it pretty much cleared off in the afternoon, and the hole phenomenon ended.

The End.

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Yesterday, one of these went over (“the rest of the story”)

First, the background, precursor shot:

11:23 AM. Altocumulus perlucidus.
11:23 AM. Altocumulus perlucidus.

Then this, looking straight up when CMP first noticed it because he wasn’t paying attention:

11:24 AM.
11:24 AM.

A few minutes  later, as it moved away:

11:27 AM.
11:27 AM.

What happened?  How cold were these Altocumulus clouds?

(Answers printed upside down below).

There were more, off in the distance, too.

Here are a few more shots of this phenomenon:

11:29 AM. As it went over the horizon to the east.
11:29 AM. As it went over the horizon to the east.  You can really see how strange it made the sky look.  Note, too, the contrail from a much higher flying aircraft (at Cirrus levels).
4:02 PM. Those fine trails of virga, center of photo, were "probably" created by an aircraft. They don't look natural to me, though when this happens without producing a ice canal or a clearing, its much more difficult to be certain. Those trails look too flat, a result of likely very high concentrations of ice crystals, all of which remain small due to the competition for the vapor in that cloud, and would be too small to collide with cloud droplets. There would be no hole or canal because the rise rate of the layer is producing droplet cloud faster than the ice crystals could take it away. In the prior photos with the ice canal, which did not fill in, you can guess the rise rate of the layer that produced the Ac per was nil. Those clouds did not fill in as the ice settled downward and out of the layer. Whew, lotta typing just then.
4:02 PM. Those fine trails of virga (center of photo, trailing in strands to the right), were “probably” created by an aircraft. They don’t look natural to me, though when this happens without producing a ice canal or a clearing, its much more difficult to be certain. Those trails look too flat, a result of likely very high concentrations of ice crystals, all of which remain small due to the competition for the vapor in that cloud, and would be too small to collide with cloud droplets. There would be no hole or canal because the rise rate of the layer is producing droplet cloud faster than the ice crystals could take it away. In the prior photos with the ice canal, which did not fill in, you can guess the rise rate of the layer that produced the Ac per was nil. Those clouds did not fill in as the ice settled downward and out of the layer. Whew, lotta typing just then.
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5:23 PM. Numerous holes were being punched in that cold Altocumulus layer out to the southwest of us. If you are pretty observant, you know that there is an airway out there, often filled with contrails. These, though are likely produced by those aircraft below the normal Cirrus levels, but rather would be ones departing or landing, in descent or climb modes, maybe from TUS?
5:41 PM. Pretty, but not natural.
5:41 PM. Zooming; pretty virga, but not natural.

Now, we’re really quitting because I have other things to do, ones that have to be done, like discovering why our attic has so many rodents in it?  Well, one, every so often,  dammitall.  Why is life one problem after another?

2017010212Z_SKEWT_KTUS
The pre-dawn TUS sounding, PRESUMMED representative of that Ac per layer. It would have been where the two lines pinch together, and if somehow you can read the temperature, its between -25° and -30° C.
For the evening aircraft effects, there are two choices of layers. Probably was the lower, warmer one IMO.
For the evening aircraft effects, there are two choices of layers. Probably was the lower, warmer one IMO.

——————————–

Answers not printed upside down instead:

It was an ice canal created in a highly supercooled layer of Altocumulus perlucidus.  How cold?  Whenever you see one of these in  a middle cloud like Altocumulus, you can guess that its colder than -20° C.  They’re rarely seen in warmer clouds.  The TUS soundings suggested this layer was between -25° and -30° C.  It mostly was ice free, bur regions of some slight (natural virga) were seen,

It was probably created by a jet, though the rarer prop aircraft can’t be ruled out.  Seems to be associated with cooling around prop tips or some say over the wing cooling momentarily below around  -40° C, though visually I would offer that  its from the water-loaded exhaust, at least in jets, rather than air cooled as it goes over the wing.

The End

Strange sunset brew of clouds and color; but was it natural?

Cutting to the chase:  I don’t think so.

Yesterday,  after an ordinary beginning,,  finished in a spectacular, if likely artificial way.  Let us work our way through yesterday’s cloudulations:

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7:39 AM. I thought this was a cute display by this little cloud, making its own little shadow rays as the sun made its way up from behind the Catlinas.
7:40 AM. But what kind of cloud is it? It, to these eyes, is all ice, but LOOKS like an Altocumulus cloud. But those clouds are all or mostly comprised of liquid drops. And you can see that this little guy is well BELOW a higher layer of ice cloud, we might call CIrrostratus, or a thin Altostratus. Oh, well, let’s move on to something explicable….

 

7:41 AM. Hmmmm. Quite a linear virga feature over there.
7:41 AM. Hmmmm. Quite a linear virga feature over there.  There are THREE cloud layers evident here, a thin Altocumulus layer, that dark cloud on the left, and patch of what I could call, Altostratus extending from the left corner to the right corner, and a thin layer of CIrrostratus on top.
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7:41 AM. Let’s go zooming and check it out…. Though we don’t know for SURE, anytime you see this kind of linear virga anomaly, you should be smelling aircraft exhaust.  Now, when you think about our fabulous sunset last evening and what that looked like, take a closer look at this photo.

Later that morning…..

10:53 AM. 10:47 AM. It was nice to see low clouds topping Sam Ridge, the lower boundary layer air (where convection takes place) moist for a change.
10:53 AM. It was nice to see low clouds topping Sam Ridge at dawn yesterday, the lower boundary layer air (where convection takes place) moist for a change.  Later they devolved into small Cumulus (humilis and fractus).
3:29 PM. A day with mostly ice clouds on top of Catalina, but here, off in the distance below the Cirrostratus, is an invading layer of Altostratus and Altocumulus that will set the stage for sunset glory later.
3:29 PM. A day with mostly ice clouds on top of Catalina, but here, off in the distance below the Cirrostratus, is an invading layer of Altostratus and Altocumulus that will set the stage for sunset glory later.  You may be able to detect a faint halo, upper center.  By the way, Cirrostratus typically deepens downward to morph into Altostratus, usually an ice cloud, too, but is deep enough to produce gray shading, and when its really thick or has embedded droplet clouds, hides the sun.
4:02 PM. Yep, moving right in.
4:02 PM. Yep, moving right in.  This is a very complex scene.  There’s aCirrostratus ice layer. upper right quadrant , on top of everything.  Below that, what appears here as a distinctly lower separate layer, a mix of Altocumulus (those dark cloudlets composed all or mostly of liquid droplets) and Altostratus (mostly or all ice, the smudgy more diffuse dark areas) .  We can never forget that Altocumulus can morph into Altostratus, which would then be called, “Altostratus altocumulotransmutatus.”  Tell that to your friends!  (Well, maybe not.)
4:15 PM. Caught this bumpy aircraft contrail at CIrrus levels. Look how how the exhaust and water vapor that formed this, though output from an aircraft in a steady state, how the wing tip vorices (apparently) get entertwined at regular intervals with more exhaust and water vapor in those blobs.
4:15 PM. Caught this bumpy aircraft contrail at CIrrus levels. Look how how the exhaust and water vapor that formed this, though output from an aircraft in a steady state, how the wing tip vorices (apparently) get entertwined at regular intervals with more exhaust and water vapor in those blobs.

But let’s go zooming up to flight level and take a closer look for a second:

A mammatus (or as the ladies like to call it) testicularis contrail. Almost certainly this is due to combining wing tip vortices. Many aircraft now have devices to defeat wing tip vortices, phenomenon that reduce flight efficiency.
A “mammatus” (or as the ladies like to call it. a testicularis contrail (the resemblances are pretty good). Almost certainly this is due to combining wing tip vortices.  Many aircraft now have devices to defeat wing tip vortices, phenomenon that reduce flight efficiency.  In both cases above, the ice particles have not grown enough to produce fallstreaks.  These images tell us that SOME aircraft that produce ice in supercooled Altocumulus clouds, as we in Catalina have seen lately, are likely to have bunches of ice trails rather than a continuum if produced in a uniform cloud, anyway.

Now, where was I?  Got mammatus on my mind again. I love mammatus so much…   Oh, yeah, that sunset yesterday…..

5:13 PM. Ran out to check sunset status, and saw this feature advancing rapidly toward Catalina.
5:13 PM. Ran out to check sunset status, and saw this feature advancing rapidly toward Catalina.
5:18 PM. Zoomed view; getting close to passing overhead. You might be able to notice that these pretty regularly spaced trails are BELOW the Altocumulus clouds, and there's a clearing that's been produced. All evidence of an artificial production of these trails. But belng below the Altocu, you might also have started to wonder whether the setting sun would light them up....
5:18 PM. Zoomed view; getting close to passing overhead. You might be able to notice that these pretty regularly spaced trails are BELOW the Altocumulus clouds, and there’s a clearing that’s been produced. All evidence of an artificial production of these trails. But belng below the Altocu, you might also have started to wonder whether the setting sun would light them up….

And the sun did its job….producing one of the greatest sunset scenes we’ve seen in a long time, even if phony (haha):

5:23 PM. Not zoomed, still a few minutes away to overhead passage. Very exciting to think this was going to pass overhead!
5:23 PM. Not zoomed, still a few minutes away to overhead passage. Very exciting to think this was going to pass overhead!
5:23 PM. Zoomed view. Again the pretty regular spacing is circumstantial evidence that nature didn't do it.
5:23 PM. Zoomed view. Again the pretty regular spacing is circumstantial evidence that nature didn’t do it.
5:25 PM. Thank you sun! Looks pretty round again, which is good.
5:25 PM. Thank you sun! Looks pretty round again, which is good.
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5:27 PM. Oh, so pretty.
5:27 PM.
5:27 PM. Zooming again. Wow.
5:28 PM. Another view of the same thing.
5:28 PM. Another view of the same thing.
5:28 PM. Our trails compared to the rest of the Altocumulus deck. Not much going on elsewhere in the way of natural virga.
5:28 PM. Our trails compared to the rest of the Altocumulus deck. Not much going on elsewhere in the way of natural virga.
5:29 PM. Taking WAY too many photos of the same thing. Out of control... Here I demonstrate that with another photo of the same thing.
5:29 PM. Taking WAY too many photos of the same thing. Out of control… Here I demonstrate that with another photo of the same thing.

 

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5:30 PM. After the trail hoopla, it was time to concentrate on the fabulous sunset taking place to the southwest of Catalina.
5:30 PM. Zooming in on interesting features; long trails, one with a clearing above it. Was it another aircraft-induced trail of ice and clearing above it? Probably. The trails to the left aren't as obviously produced by an aircraft, but I do think so anyway in this burst of objectivity. Recall that I have been trained as a "scientist" and don't care if I am wrong, but only about truth, as best as I can make it out.
5:30 PM. Zooming in on interesting features; long trails, one with a clearing above it. Was it another aircraft-induced trail of ice and clearing above it? Probably. The trails to the left aren’t as obviously produced by an aircraft, but I do think so anyway in this burst of objectivity. Recall that I have been trained as a “scientist” and don’t care if I am wrong, but only about truth, as best as I can make it out.

Finally, let look at the TUS sounding for last evening, see how cold those Ac cloud were with the ice trail in them:

The Tucson rawinsonde balloon launch yesterday at about 3:30 PM. Goes up at about 1,000 feet a minute, so takes about 100 minutes to get to 100, 000 feet. They pop somewhere around that height or a little above. THought you like to know that. They have a little parachute to that when they come down, they don't bonk you too hard. Once in awhile people find them in remote areas downwind.
Results of the Tucson rawinsonde balloon launch yesterday at about 3:30 PM. Goes up at about 1,000 feet a minute, so takes about 100 minutes to get to 100, 000 feet. They pop somewhere around that height or a little above. THought you like to know that. They have a little parachute to that when they come down, they don’t bonk you too hard. Once in awhile people find them in remote areas downwind.  You can send them back in to the NWS, too!

The astounding thing here, something that goes against everything I believe about clouds, is that it is indicated that the Altocumulus, lacking much natural ice, was at -30° C!  Yikes!  No wonder aircraft were producing ice trails and stuff yesterday afternoon.

You have to conclude there were almost no natural “ice nuclei” up there at, oh about 24,000 feet above sea level.  This is not the first time for such an occurrence of liquid clouds sans much ice at low temperatures1, but they are rare IME.  This would never occur in a boundary layer cloud, that is, one where material from the earth’s surface is getting into the clouds,  like the omnipresent dust, or biogenic ice nuclei.

The weather ahead

Some “fantasy” storms with rain in them for Catalina, are now seen on the model predictions beyond a week.  Spaghetti is favoring this new development now.  So, something to keep an eye on.

The view from here?  Precip here is “in the bag” because going on subjective feelings, I really want to see a good rain here!

 

The End

——————————
1The famous John Hallett said he saw an Altocumulus lenticularis sans ice at -35°C in a conference preprint! Rangno and Hobbs (1986) claimed to have detected droplets in Altocumulus like clouds at the top of a storm on the Washington coast at -44°C. Their claim, first published in a conference preprint, was later rejected by the J. Atmos. Sci.

In case you missed them…a 2008 full moon and, moving ahead, yesterday’s sunrise

The full moon of December 11, 2008. Thought maybe you'd like to see it again coming up over the Catalinas.
The full moon of December 11, 2008. Thought maybe you’d like to see it in case you missed it, or see it again if you did see it.  Maybe you had a special memory with this moon.
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7:09 AM. Altocumulus perlucidus with a little lenticular underneath.
7:43 AM.
7:10 AM. Zooming and zooming.
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7:10 AM. Zooming some more.
7:14 AM. Iridescence is evident in the cloud ripples just above the mountain silhouette.
7:14 AM. Iridescence is evident in the cloud ripples just above the mountain silhouette.
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7:16 AM, Contrails were soon visible in our Altocumulus layer, the aircraft making it at the right edge of the photo. Appeared to be in a climb out going right to left. And, when you see these “high temperature contrails” in Altocumulus, you can be sure ice will form and rifts will develop as a little bit of light snow develops and falls out.  The jillions of ice crystals in the contrail cause the droplets in the Altocumulus to evaporate, in a way, gutting it. An ice crystal is like a low pressure center when amid droplets;   the droplets evaporate and those water molecules deposit themselves on the ice crystal, a process named after the discoverers, Wegner-Bergeron-Findeisen.   Eventually the crystal is large enough to settle out and a clear streak results unless the air is rising rapidly and can replace the droplets (as generally happens in storms).  Sometimes the lift in the Altocumulus layer is enough that a clear canal caused by an aircraft can fill back in after many minutes.
7:18 AM. Two aircraft contrails, about a minute old.
7:18 AM. Two aircraft contrails, about a minute old.  After two or three more minutes, they will not be visible within the cloud, though ice is forming, decimating the droplets around the intense streamers of ice in the contrail.
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7:28 AM. The small ice canal (the ice is hanging just below the Altocumulus clouds–kind of hard to make out, but its there.
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7:42 AM. Those little clear streaks are hardly noticeable now, partly because they were quite narrow, and because of perspective and things bunching up in the distance.

 

From the Cowboys in Laramie, Wyoming, this TUS sounding for yesterday morning in the pre-dawn hours:

Suggested locations of cloud layers. The Altocumulus layer in which the contrails were embedded seems to be at -25°C, a "normal" temperature for this kind of "high temperature contrail". In general contrails are not supposed to occur until the temperature is below about -35° C and the air is moist, thus they are usually seen amid or near Cirrus clouds. not down in Altocumulus.
Suggested locations of cloud layers. The Altocumulus layer in which the contrails were embedded seems to be at -25°C, a “normal” temperature for this kind of “high temperature contrail”. In general contrails are not supposed to occur until the temperature is below about -35° C and the air is moist, thus they are usually seen amid or near Cirrus clouds. not down in Altocumulus.   See usual contrail height at Cirrus levels  in moon photo.

As the morning wore on, the Altocumulus deck faded away, moving east, and we were left with some Cirrus clouds, but what kind?

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10:58 AM. Cirrus of some type, but notice there is absolutely no fibrous details (strands and such) as we normally see in Cirrus.  Could be transverse waves in a Cirrostratus deck since Cirrostratus can be fog like, have no detail, in a version we call, Cirrostratus nebulosus.  The up and down motions would cause clearings perpendicular to the wind up there.  The lack of strands and uniformity in these bands suggests very tiny ice crystals, ones having very little fallspeeds.
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2:34 PM. Some nice “hovercraft” clouds, Altocumulus lenticularis off in the distance SSW. Hung around out there for a couple of hours.
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3:17 PM. This one appeared to be concave upward, which was a little odd. Zoomed view next.
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3:17 PM. Looks like the inside is higher than the outside. Huh.

Well, that was  it for photography yesterday.

Doesn’t seem to be any reliable indication of rain in sight.   Oh, sure, rain here pops up in the models almost every day, but its about 12-15 days out.  As the model gets closer to the day it predicted rain, it seems to go away like the “water mirage” on a hot paved road; always ahead of you, but you never get to it.  We’ve had some major rains indicated in the models as of a few days ago, but spaghetti was never very high on those events (clustering those crazy lines in a trough over us), so it wasn’t even worth mentioning.

And, even that rain is a gonner in the model runs from last night!

The End

A stragne and wonderful day

Many strange1  and wonderful sights were seen yesterday; I could feel the excitement out there as one cloud  microstructural mystery after another regaled our Catalina skies.

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7:24 AM. Here, a tiny highlighted flake of Altocumulus floating above a mass of light snow/ice crystals, maybe straight below it. This is one the classic mysteries we deal with in “cloud microstructure”;  the oddity of nature preferring to generate a droplet before an ice crystal at least to somewhere in the -30°s C. Liquid clouds often are at the top of Altostratus and Nimbostratus (rainy or snowy days) providing the tops aren’t too much colder than -30° C. How strange is it to have liquid water at the lowest temperatures in a cloud system, with all the ice and snow underneath, as shown in this photo (though here they are no longer connected).
7:24 AM/ I think there is itty bitty droplet cloud at the very top bright dot there.
7:24 AM/ I think there is itty bitty droplet cloud at the very top bright dot there.  A droplet cloud was likely much broader to have produced all the ice we see below that bright dot of liquid cloud.
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7:26 AM. Looking afar, to the SW, there’s what appears to be an Altocumulus (droplet cloud) with a few ice crystals underneat it, especially to the right.

How cold are these clouds?  Lets look at the TUS sounding, launched at about 3:30 AM yesterday morning.

The TUS rawinsonde balloon data for yesterday morning before dawn.
The TUS rawinsonde balloon data for yesterday morning before dawn.  That Altocumulus layer, and the other clouds above were likely at the pinched point above, topping out at -27°C and up around 23,000 feet above sea level (400 millibars), pretty darn cold.  But, as you saw in the 3rd photo, not a lot of ice is being generated at this temperature by that patch of Altocumulus clouds to the SW.  Not sure why, but its pretty remarkable and that is likely due to small droplet sizes AND a lack of ice nuclei, most of which are known to originate with soil particles  When you see these rare occurrences of all or mostly droplet clouds at low temperatures (<-20° C in particular, get ready to see hole punch and ice canals produced by aircraft, a kind of inadvertent cloud seeding.

That bank of Altocumulus was racing at more than 50 mph toward Catalina, and so it got here in a hurry.    And, as it got closer, it was also getting more into some airways at that height, possibly descents into PHX since the height of those clouds was below normal jet cruising levels at 23,000 feet Above Sea Level.

7:55 AM. This is one of the strangest sights I have ever seen. Why? On the left side of this photo, the clouds are completely glaciated, composed of ice, while along a line to the right, there's no sign of ice in Altocumulus clouds that appear to be at the same height (namely, temperature). I have no explanation for this scene, except those involving a lot hand-waving, so we'll just let go.
7:55 AM. This is one of the strangest sights I have ever seen. Why? On the left side of this photo, the clouds are completely glaciated, composed of ice, while along a line to the right, there’s no sign of ice in Altocumulus clouds that appear to be at the same height (namely, temperature). I have no explanation for this scene, except those involving a lot hand-waving, so we’ll just let go, except that we speculate that the Ac layer was a little lower (warmer)?  Could have been.

Now for the aircraft effects.  Hardly a few minutes go by before aircraft began marking up this cold Altocumulus layer.  Notice that it doesn’t seem to be producing much or any ice on its own, making aircraft inadvertent seeding lines and holes where tremendous numbers of ice crystals are generated immediately present.   Here’s the first of many:

8:16 AM. An icy canal due to the passage of an aircraft rips through this pristine layer of Altocumulus whose temperature was around -25° C.
8:16 AM. An icy canal due to the passage of an aircraft rips through this pristine layer of Altocumulus whose temperature was around -25° C.  The view is looking S toward Tucson, but is unlikely to have been an aircraft landing there because this layer was above 20,000 feet Above Sea Level.  An aircraft lanidng at TUS would be much lower, this close.  The passage of the aircraft was likely 10 or more minutes before this photo.
8:19 AM. The ice canal is broadening due to turbulence, and ice is not plainly evident to all Cloud Maven Juniors or we will have to go over discerning ice from droplet clouds at the next club meeting.
8:19 AM. The ice canal is broadening due to turbulence, and ice is not plainly evident to all Cloud Maven Juniors or we will have to go over discerning ice from droplet clouds at the next club meeting.
8:20 AM. A view of the northwest end of this aircraft-produced ice canal. Several others became apparent, too.
8:20 AM. A view of the northwest end of this aircraft-produced ice canal. Several others became apparent, too.

Heading for Catalina, this:

9:11 AM. Heading for Catalina, a whole mess of aircraft induced ice in that poor Altocumulus layer. The hole punch was likely due to an aircraft climbing out of or descending into TUS. The age of a hole that large, with ice below it like this would be something of the order of at least half an hour to an hour old. Just behind the hole is a new contrail in the Ac clouds,
9:11 AM. Heading for Catalina, a whole mess of aircraft induced ice in that poor Altocumulus layer. The hole punch was likely due to an aircraft climbing out of or descending into TUS. The age of a hole that large, with ice below it like this would be something of the order of at least half an hour to an hour old. Just behind the hole is a new contrail in the Ac clouds,
9:23 AM. Hole punch area and ice canal arrive over Catalina! Losing control here, taking photo and photo, now looking for stragne optics, usually observed with aircraft produced ice particles because they are so numerous, compete for the available moisture and therefore remain tiny and perfect, prisms, plates, short column ice crystals, ones that can do a lot of optical stuff.
9:23 AM. Hole punch area and ice canal arrive over Catalina! Losing control here, taking photo and photo, now looking for stragne optics, usually observed with aircraft produced ice particles because they are so numerous, compete for the available moisture and therefore remain tiny and perfect, prisms, plates, short column ice crystals, ones that can do a lot of optical stuff.

Here’s the south end of that ice canal:

9:24 AM.
9:24 AM.  Also note iconic horse wind vane, and real wind vane atop a personal weather station.  Doesn’t everyone have a “PWS”?

Looking straight up at the icy heart of a hole punch region caused by an aircraft.  I am sure you have never done this before!  This is gonna be a great blog with all these new things for you!

9:27 AM. Look at the detail in the ice, those fine, fine strands! Amazing. The thickest strand might be due to the higher liquiid water in the heart of one of those little Altocumulus cloudlets. ???
9:27 AM. Look at the detail in the ice, those fine, fine strands! Amazing. The thickest strand might be due to the higher liquiid water in the heart of one of those little Altocumulus cloudlets. ???  Look how much wind shear there is, those little itty bitty ice crystals falling so far behind the parent cloud, the streamers flattening out because the poor little guys, already undersized to begin with, are getting smaller and smaller, the fall velocity getting less and less until the strands are almost horizontal.
9:27 AM. Looking at this gorgeously uniform layer of Altocumulus perlucidus 9honeycomb of elements) translucidus (no shadows).
9:27 AM. Looking at this gorgeously uniform layer of Altocumulus perlucidus 9honeycomb of elements) translucidus (no shadows).  To me this is a phenomenal scene, though maybe to u, not so much, which is understandable.
9:30 AM. The expected intense optical phenomena began to occur in these aircraft contrail remains.
9:30 AM. The expected intense optical phenomena began to occur in these aircraft contrail remains.  Here a parhelia, or sundog.  More fireworks in a bit.
9:30 AM. While the parhelia was in its full display, very intense, this was the ice canal passing overhead. Look at the regular spacing of these strands of ice, Might be due to the spacing of the cloudlets in the Altocumulus layer, the spaces between them not producing much ice, or, as we know, contrails tend to clump behind the aircraft likely due to wingtip vortices interacting and combining masses of exhaust water and crud.
9:30 AM. While the parhelia was in its full display, very intense, this was the ice canal passing overhead. Look at the regular spacing of these strands of ice, Might be due to the spacing of the cloudlets in the Altocumulus layer, the spaces between them not producing much ice, or, as we know, contrails tend to clump behind the aircraft likely due to wingtip vortices interacting and combining masses of exhaust water and crud.   This is now about an hour and fifteen minutes old, since we saw it way out to the west at 8:16 AM shortly after it formed.
9:37 AM. Here's what a new aircraft contrail in these clouds looks like, this one about 60 s old looks like
9:37 AM. Here’s what a new aircraft contrail in these clouds looks like, this one about 60 s old looks like.  Note all the irregularity in the contrail from the get-go.

As the south end of the original ice canal began to enter the refraction zone for simple ice crystals around the sun, usually at the 22° degree halo position, things began to light up with a particularly bright circumzenithal arc (more often observed on a halo) or colorful (in this case) partial  “reverse halo”.   The colors (iridescence)  due to the refracting of light within very small ice crystals.   Normally iridescence is seen near the sun in Cirrocumulus clouds or the then edges of other droplet clouds.   Very exciting.

9:44 AM. Halo curving in the wrong direction, away from the sun!
9:44 AM. A part of a halo curving in the wrong direction, away from the sun! (This is actually called a circumzenithal arc).
9:44 AM. Taking up you up thousands and thousands of feet via a zoomed view.
9:44 AM. Taking up you up thousands and thousands of feet via a zoomed view.   Pretty cool, eh?  Notice how much its moved in just seconds,  You really have to let your coffee get cold if you’re a photographer and you want to get the best shots of this kind of phenomenon.  You really can’t do anything but keep watching every second!
9:44 AM, again. All these changes took place within the minute between 9:44 and 9:45 AM!
9:44 AM, again. All these changes took place within the minute between 9:44 and 9:45 AM!  Here, the next grouping of ice strands is being lit up.
9:48 AM. Just a pretty scene. Altocumulus perlucidus translucidus, pocked with aircraft contrails, if you look real close.
9:48 AM. Just a pretty scene. Altocumulus perlucidus translucidus, pocked with aircraft contrails, if you look real close.  Make me move:  $1 billion dollars…
9:54 AM. Its not even 10 AM and now this comes along, this fabulously complex zone of CIrrocumulus (at the same level of the Ac clouds) at the tail of the Altocumulus. You can see the much higher Cirrus going crossways, lower center. See TUS sounding for height of Ci.
9:54 AM. Its not even 10 AM and now this comes along, this fabulously complex zone of CIrrocumulus (at the same level of the Ac clouds) at the tail of the Altocumulus. You can see the much higher Cirrus going crossways, lower center. See TUS sounding for height of Ci.

Then this strange sight:

12:29 PM. A row of Altocumulus or Cirrocumulus, each formed by a little upward bump in the atmosphere of a layer just a hair below saturation. Just rising a few hundred feet or so causes these cloudlets to form. Why aren't they everywhere? Might be drier. Bumps like this are always present in the atmosphere, especially if there are mountains upwind.
12:29 PM. A row of Altocumulus or Cirrocumulus, each formed by a little upward bump in the atmosphere of a layer just a hair below saturation. Just rising a few hundred feet or so causes these cloudlets to form. Why aren’t they everywhere? Might be drier. Bumps like this are always present in the atmosphere, especially if there are mountains upwind.  Not taken while driving, of course, ; just looks like it thanks to photoshop.

The day closed out with a lower layer of Altocumulus moving in, this layer, according to the TUS sounding, at “only’ -17° C, and little ice detected.  Below, at 2:09 PM:

2:09 PM. Altocumulus perlucidus translucidus. A natural conversion to ice is occurring on the right side of the photo.
2:09 PM. Altocumulus perlucidus translucidus. A natural conversion to ice is occurring on the right side of the photo.
DSC_9836
4:42 PM. So pretty these Altocu.

 

4:41 PM. A strand of finely patterned Cirrocumulus shot out of the SW as the sun declined.
4:41 PM. A strand of finely patterned Cirrocumulus shot out of the SW as the sun declined.
The Tucson afternoon rawinsonde . launched around 3:30 PM.
The Tucson afternoon rawinsonde . launched around 3:30 PM.  The Cirrocu in the above photo was likely also at the Cirrus level indicated above.

U of AZ mod thinks so light rain will develop around here in the mid-later afternoon.

The End

—————————————–

1“stragne” above, originally an inadvertent typo, but left in place as another cheap trick to get draw the curiosity of readers who might wonder what stragne is.

Awesome evening skies leave Catalinans with but a trace of rain, but over there by Picture Rocks, they got over an inch!

“Too many pictures, for one site…”, a continuing theme here1, to paraphrase “? and the Mysterians1“.

Two stations near Picture Rocks reported 1.25 and 1.35 inches, respectively, so some major rain fell fairly close to us.   You can see the amount arounds around the State or here  at the Banner U of AZ rainlog,org site.

Below your October 8th, 2016 cloud day, a Saturday in which the author’s former company fubball team, the Washington Huskies, spanked the Nike University of Oregon Duck, 70-21, ending years of futility against the billionaire’s sports teams.  Too bad Washington multi-billionaire Gates is more interested in saving the world  instead of helping the Huskies get better in sports like Phil Knight does with The Duck there in Duckville, OR….

Oh, well,  off task there for a minute.  I’m back now!

7:06 AM. Pretty Cirrus uncinus with a few Altocumulus over on the left.
7:06 AM. Pretty Cirrus uncinus  (tufted ice clouds with the larger ice crystals falling out where the wind is not as strong as where the head is)  with a few Altocumulus over on the left.
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8:43 AM. The really sharp-eyed cloud maven junior person would have noticed these little icy trails in a sliver of Altocumulus or Cirrocumulus. These supercooled clouds were converted to ice along the path of the aircraft. The brighter one is the most recent one and is so white due to the extremely high concentrations of tiny (order of 10s of microns) germ-like ice crystals. Concentrations would be something like 10s of thousand per liter. Once formed, they compete for the available moisture, some evaporating, some able to grow larger and fall out just as ice crystals do in Cirrus clouds. The less white trail is older and is one where the crystals are spreading out and also evaporating so the concentrations are much less. Presently it is believe that the air going over the wing of a jet drops the temperature to below -39° C where crystals form spontaneously and can survive and grow within a supercooled water cloud egad this is getting to be a long caption.

Now, here where the excitement begins.  Recall Mike L. and Bobby Maddox, both super experts concerning convection, called for severe storms and large hail today due to what the models were showing in the vertical wind profile and the amount of moisture available.  Below, we start yesterday chapter of convection, and see where it leads.

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3:47 PM. Beginning to think Mike L and Bobby M are going to be wrong. Cumulus in the heat of the day have only reached moderate, “congestus” sizes around here, though Cumulonimbus cloud tops can be seen off in the distance.
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2:50 PM. Another pretty sky scene with an ineffectual Cumulus congestus there north of Saddlebrooke. Looks like is has a little ice ejecta on the far right, middle. But see how any rain would fall out not within the main cloud body but out the side away from the base. More evaporating of any drops would occur. This is happening due to the moderate southwesterly winds higher up, with slower winds from the south below. Thinking about taking a nap….
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2:51 PM. On second thought, maybe I should see how the septic repair is going…. Looks OK. Wonder how many thousands it will be?
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2:58 PM. Even though it looks like Mike and Bob are still going to be wrong, at least someone’s getting some good TSTMS (weather text for “thunderstorms” in case you do that, but don’t do it whilst you’re driving, a public message from your CMP. Some cloud science: On the right is a turret that’s climbed up beyond the level of “glaciation” but still contains tons of water. Center left, is a complex of turrets a little behind that one that are taller, and in those tops you woud find little or no water, just ice crystals. Can you see the difference in texture between the rising turret full of water (though graupel, hail, and small ice crystals are likely inside it)
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3:58 PM. Septic crew was asking, “where’s the hail you said would happen today?” I corrected them by saying that Mike and Bobby told me that, I didn’t personally make that forecast. I told them, hang on, things are starting to happen. And, about this time, the NWS started to issue severe TSTM alerts for Cochise County due HAIL and high winds! Still, it didn’t yet look that great for us here in Catalina, Oro Valley area. The Cbs shown here are that “tough.”
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4:27 PM. Still kind of bored, think I’ll take picture of an interesting shadow pattern.
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4:34 PM. Gads, looks awful out there. Only the anvil is left of a former thunderstorm toward Twin Peaks as the wind shear aloft rips from it from its root base. Not too bad there on the left, though. Still looks like a dud day for us in Catalina anyway at this moment.
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4:55 PM. Modest Cumulonimbus forms in the lee of the Charouleaiu Gap. Notice here that looking to the NE you can only see the rising turret part of this Cumulonimbus. The anvil is trailing downwind away from you, some of that anvil can be seen at the far right,just above the ridge. But you can clearly see some precip is falling out of this, Code 1 (transparent shaft) likely because as we saw earlier, the precip is not falling through the whole depth of the cloud but is falling from a higher portion of the cloud that has been blown off toward the NE before the precip got going in it.
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5:01 PM. Yikes, when did this happen? Must have been between commercials during football viewing.  You can only go outsie during commercials so you miss some things.  Bobby and Mike are going to be correct for our own backyard! Hope we get something, and it appears to be upwind of Catalina!
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5:06 PM. Just because it was pretty. Cumulus congestus tops, brilliantly white (that higher one in the back).
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5:31 PM. More commercials allow a quick trip down the road to get this. Of concern, the shafting is shifting rightward and away from us. What’s upwind is now the Code 1 transparent rain. BUT, the base in the middle of the photo, and close by, looks great! Perhaps some stupefying dump will emerge from that and grow more good base material exactly upwind of us!
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5:58 PM. Another discouraging day of promise gone unfulfilled here in Catalina/Sutherland Heights. Feelling sad, though I would take a funny picture of my shadow whilst walking the dogs at half time, makes me look bigger than I really am. made me smile amid the dismal sprinkle that started to fall, giving us yet another “trace” of rain day.
6:06 PM. There goes our complex of rain, thunder and lightning off into the distance. Still, the scene was great.
6:06 PM. There goes our complex of rain, thunder and lightning off into the distance. Still, the scene was great.
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6:08 PM. Day ended with some dramatic, colorful scenes, something said here alot, but true.

 

The End.

 


1If you don’t believe ? said something like that, go  here

A nice cloud yesterday, not a great cloud yesterday; dramatic day ahead

The clouds were somewhat of a disappointment yesterday, not the stupendous photogenic day CM was expecting.

Maybe CM is total fraud, gets Big Oil funding and should be investigated by Rep. Grijalva as other weather folk are,   like the great Prof. and National Academy of Sciences Fellow,  Dr. Judy Curry,  a friend, and about whom I say on a link to her blog here, and from this blog’s very beginning, “The only link you will need.”  I said that because Judy2 is a top scientist, and is eminently fair in this polarized issue.

I am in real trouble!  Will remove that link immediately1 before our very own  “climate thought enforcer”,  Demo Rep. Grijalva, AZ,  finds it using a spy bot!  No telling how far down the influence chain it will go, maybe all the way down to here, where there is virtually no influence!

Back to clouds…….

Only late in the day did the delicate patterns expected to happen ALL DAY appear, again, with iridescence, always nice to see.

Here is your day for yesterday.  Its a pretty interesting movie.  Two thumbs up!

Oh, today’s weather?

The media, Bob,  and our good NWS, of course, are all over the incoming rain in great detail.  In fact, it will take you half a day to read all the warnings on this storm issued by our Tucson NWS.

So why duplicate existing information that might be only slightly different than the prevailing general consensus on the storm amounts, and then maybe be investigated for going against a consensus?   No, not worth it.   Best to be safe, not say things against The Machine.  (OK, maybe overdoing it here.)

In the meantime, the upper low off southern Cal and Baja has fomented an extremely strong band of rain, now lying across SE Cal and the Colorado River Valley where dry locations like Blythe are getting more than an inch over the past 24 h.   Same for northern Baja where some places are approaching 2-3 inches, great for them.  You can see how the rain is piling up in those locations here.  In sum, this is a fabulous storm for northern Mexico and the SW US, whether WE get our 0.915 inches, as foretold here, or not! Rejoice in the joy of others.  Looking for an arcus cloud fronting the main rainband, too, that low hanging cloud in a line that tells you a windshift is coming.  Still expecting, hoping, for thunder today to add to the wind and rain drama.

Also, the present cloud cover, as the trough ejects toward us, will deepen up and rain will form upwind and around here as that happens, so it won’t JUST be the eastward movement of the existing band.  This means you might be surprised by rain if you’re outside hiking and think the band itself is hours away.  Expecting rain to be in the area by mid-morning, certainly not later than noon, with the main blast (fronted by something akin to an arcus cloud) later in the day.  OK, just checked the U of AZ mod run from 11 PM AST, and that is what it is saying as well!  Wow.

Finally, if you care, yesterday’s clouds:

6:45 AM.  Your sunrise color, thanks to a line of broken Cirrus spissatus. Jet stream Cirrus streak, as a matter of fact.
6:45 AM. Your sunrise color, thanks to a line of broken Cirrus spissatus. Jet stream Cirrus streak, as a matter of fact, moving along at about 110 mph.
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9:47 AM.  Ruffle of Sc topped Mt. Lemmon, while strange clouds formed just upwind of them. These kinds of shapes suggest an inversion where the air resists further upward movement and a smoothing occurs at the top similar to a lenticular cloud.  Photo taken at the Golder Ranch Dr. cattleguard. which really doesn’t work that well, as the neighbors below here will tell you.
The 5 AM, March 1st,  balloon sounding for TUS.
The 5 AM, March 1st, balloon sounding for TUS.
9:53 AM.  Looks like a crab with four hooks.  How funny.
9:53 AM. Looks like a crab with four pinchers. How funny.
12:23 PM.  Shredding tops of small Cumulus like this indicate that the air is very dry just above their tops, and the shreds racing off to the right, indicate how fast the wind increased as you went upward.
12:23 PM. Shredding tops of small Cumulus like this indicate that the air is very dry just above their tops, and the shreds racing off to the right, indicate how fast the wind increased as you went upward.
2:58 PM.  Something is changing here.  Notice how the tops are bulging and not immediately being torn into shreds.
2:58 PM. Something is changing here. Notice how the tops are bulging and not immediately being torn into shreds.  The air was likely moistening above cloud tops, and the inversion holding the tops back, weakening as our storm gets a little closer.
4:19 PM.  A line of heavy Cumulus had formed to the west, indicating more moistening and "de-stabilization" of the air.
4:19 PM. A line of still larger Cumulus had formed to the west, indicating more moistening and “de-stabilization” of the air.  However, the upper low was not advancing toward us any longer and no further development occurred as stagnated,  ratcheting up  its rainband over eastern Cal and western AZ.  The TUS balloon sounding suggested tops were getting close to the normal ice-forming level here, -10 C, the slight inversion on the morning sounding at 13,000 feet above sea level, and the one likely to have caused those smooth morning clouds,  was gone.
6:07 PM.  Just before sunset from near Oracle where we took mom for her BD.
6:07 PM. Just before sunset from near Oracle where we took mom for her BD.  The heavier Cumulus clouds faded with the sun.  They will arise today!

Below, just some pretty patterns observed later in the day.  Click to see larger versions.

3:28 PM.  Cirrocumulus began to appear.
3:28 PM. Cirrocumulus began to appear.
3:36 PM.  Twisted, tortured Cirrus (fibratus?).
3:36 PM. Twisted, tortured Cirrus (fibratus?).
3:50 PM.  Another view of Cirrocumulus. Though these clouds are still composed of liquid droplets, the 5 PM TUS sounding suggests they were at about -30 C in temperature.  It happens.
3:50 PM. Another view of Cirrocumulus. Though these clouds are still composed of liquid droplets, the 5 PM TUS sounding suggests they were at about -30 C in temperature. It happens.
4:00 PM.  An incredibly complex array of Cirrocumulus overhead.  Due to perspective, its about the only view that you can really see how complex the patterns are.
4:00 PM. An incredibly complex array of Cirrocumulus overhead. Due to perspective, its about the only view that you can really see how complex the patterns are.
4:20 PM.  Some iridescence for you.
4:20 PM. Some iridescence for you.
6:00 PM.  At Oracle, AZ.
6:00 PM. At Oracle, AZ.
6:22 PM.  Finally, from the "Not taken while driving since that would be crazy" collection, this oddity.  Looks like an high temperature contrail (aka, "APIP"). but the trail seems to shoot up into the cloud Altocumulus cloud layer (or down out of it).  Have never seen this before.
6:22 PM. Finally, from the “Not-taken-while-driving-since-that-would-be-crazy-though-it-looks-like-it-was” collection, this oddity.  Looks like an high temperature aircraft contrail (aka, “APIP”) in the lower center.  And the trail seems to shoot up into the cloud Altocumulus cloud layer (or down out of it). Have never seen that kind of aircraft track before since it looks so steep! “High temperature”  here means that it formed at temperatures above about -35 C.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Whew, the end.

——-

1Not!!!!!!  I thought this was a good read about this deplorable new stage of “climate thought enforcement” now in progress.  It was brought to my attention by climate folk hero, friend, and big troublemaker, Mark Albright.  Wow, maybe Mark will be investigated, too!  Maybe I should excise his name….

2I remember, too, how cute she was when she worked my lab/office at the University of Washington in the mid-1980s, and thought about asking her out, to detract from a serious commentary here.   She was a Penn State grad student, not a U of WA employee;  still, to ask her out would have been untoward.   A human commentary like this, one about feelings and things, help boost blog attendance.

100-150 mph winds overhead bring pretty patterns in Cirrocumulus clouds; also, an experiment in detecting the phase of clouds

If you thought those high clouds were moving faster than usual, you were right.  The winds were about 120 mph at that level, about 28,000 feet above sea level, and just over 150 mph a few thousand feet above that level.

You may have noticed two things, if you are good, that there were repeated formations of delicate Cirrocumulus clouds, likely starting as liquid drops, but quickly transitioned into Cirrus.   Sometimes, it was just flocculent Cirrus the whole way to us from the west.

The second thing that you may have noticed was that there was always an upwind clearing zone that remained stationary until late afternoon when it finally passed overhead.  Yesterday’s high clouds formed at that back edge.

How can you tell that the upwind edge of that sheet of clouds was initially composed of liquid droplets, but then froze naturally within a minute or three as it jetted downstream?

Perform an experiment to demonstrate the two phases.

In this case we will have an ice producing aircraft fly through both regions, the droplet region, and also the region where no droplets exist because they have frozen and are growing larger and larger as ice crystals.

What will be the predictable result of two ice-producing aircraft flying through these two different phases?

In the liquid cloud region, an ice canal will develop as the appearance of ice in a droplet cloud results in the evaporation of liquid droplets, the molecules of vapor from the evaporating droplets provide “food” for fattening ice crystals, where “deposition” takes place.  Under a microscope you would see the crystals getting larger, growing extensions; you would not be able to see the molecules producing that, of course.

The result of our experiment, something you likely will never see again in my lifetime:

DSC_3231

3:36 PM.  Letting the font size demonstrate the excitement I was feeling, that excitement filling the whole sky!  Maybe the temperature in this inadvertent experiment would be stupefyingly low, like -40 C (-40 F), in which case I might get a publication of my photos.  Another great aspect was that this canal was streaking toward me (us)!  It just could not have been a better situation.
3:36 PM. Letting the font size demonstrate the excitement I was feeling, that excitement filling the whole sky! Maybe the temperature in this inadvertent experiment would be stupefyingly low, like -40 C (-40 F), in which case I might get a publication of my photos. Another great aspect was that this canal was streaking toward me (us)! It just could not have been a better situation.  And I would add, in retirement mind you, to my CV and I don’t even have a grant!  It was going to be a great day!
3:40 PM.  See photo.
3:40 PM. See photo.
3:47 PM.  Normal contrail in ice cloud continues to evolve as ice canal gets closer.
3:47 PM. Normal contrail in ice cloud continues to evolve as ice canal gets closer.
3:49 PM.  The aircraft contrail that was emitted in all ice clouds.  Still are all ice, though you may say they look awfully tufted like they could have droplets. They're glaciated, all ice.  Go with me on this.  I'm the cloud maven.
3:49 PM. The aircraft contrail that was emitted in all ice clouds. Still are all ice, though you may say they look awfully tufted like they could have droplets. They’re glaciated, all ice. Go with me on this. I’m the cloud maven.
3:26 PM.  The scene before the experiment.  The upwind edge where the Cirrocu and CIrrus were forming is just above the horizon.
Helping hand points out ice canal. By this time the clouds around that ice canal had also transitioned to ice.
Also at 3:47 PM, a zoomed view of ice canal.  You can see the little ice fibers in that clearing, the ones than caused the evaporation of the droplets around the initial ice formation.  Likely at this point that the surrounding cloud, though rather "flocculent" looking was also now ice.
Also at 3:47 PM, a zoomed view of ice canal. You can see the little ice fibers in that clearing, the ones than caused the evaporation of the droplets around the initial ice formation. Likely at this point that the surrounding cloud, though rather “flocculent” looking was also now ice.
DSC_3282
3:52 PM. As usually happens with aircraft produced ice, the tiny, overabundant crystals are pristine, perfectly shaped hexagonal solid columns or hexagonal plates, and that perfect shape usually results in strong optical phenomena at the point where a sun dog or  22 degree halo is observed due to the refraction of sunlight in those crystals.  You only had seconds to see this, those clouds were moving SO FAST, and I missed the brightest point.

 

3:53 PM.  One final look at our receding ice canal, gradually being filled in by natural Cirrus.
3:53 PM. One final look at our receding ice canal, gradually being filled in by natural Cirrus.

Was holding breath, thinking about that CV enhancement, waiting for the TUS sounding, which was already in the air when these last few photos were taken, and, more importantly, it was going up near where the clouds were forming, so the moist level intercepted and its temperature would be pretty accurate for this shots.  Now, if its -40 C, oh man, we got a pub!  -36 C, maybe.  Temperature greater than about -35 C?  No pub, well, except here, which is something.  That’s because liquid drops at temperatures between -30 and -35 C have been reported by remote sensing and aircraft repeatedly.  Nature abhors forming an ice crystal in clouds without going through the liquid phase first.

Within a couple of hours the TUS sounding was in, and here it is:

The TUS balloon sounding launched about 3:30 PM, rise rate about 1,000 feet a minute.  Shows Cirrocu layer was "only" about -33 C (-27 F).  Boohoo.
The TUS balloon sounding launched about 3:30 PM, rise rate about 1,000 feet a minute. Shows Cirrocu layer was “only” about -33 C (-27 F). Boohoo.

I wasn’t going to get a journal pub.  I thought about that guy that thought he was going to win the Nobel Prize…..and I know now how he felt.science laughs_005

Now about those pretty patterns, by Simon and Garfunkel.  Enjoy.
1:08 PM.
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1:34 PM.  Forgot this nice one…..

Today’s take

Jet core at 18,000 feet now passing overhead and DRIZZLE or very light rain from warm processes now (4:15 AM) evident on the Catalina Mountains.   The passage of that jet core at that level (500 millibars) seems to be an almost  black-white measurable rain or no rain discriminator in the Southwest US, so as that happens right now, chances of some measurable rain are good.  Still not expected to be more than 0.25 inches, but will now at least be 0.01!

The low clouds are pretty shallow now, and, if they rain, shallow clouds with tops warmer than -5 C (23 F) have to be pretty clean for that to happen.  Clean clouds is got bigger droplets, ones that reach the Hocking-Jonas threshold of between 30-40 microns in size and can collide and stick together forming still much larger drops that collect more and more tiny cloud droplets, kind of a chain reaction, as Nobel Laureate in chemistry Irving Langmuir described it back in 1948 after he got interested in clouds and rainmaking.

However, the “collision with coalescence process will be short-lived as cloud tops go up to well below freezing level this morning, and real rain falls (as is happening now (7:18 AM) down in TUS and to our NW.

Measurable rain should be just on the doorstep, and it will have to develop in upwind clouds as they approach us and the air begins to rise as it goes uphill from the lower deserts and encounters the Catalinas’  there isn’t much in the way of radar echoes upwind of us now.

The development of rain in clouds as they approach us in marginal rain situations like this one is not terribly unusual.  Sometimes, as a friend pointed out, new echoes in deepening clouds can appear over and over again near where I-10 runs to the SW and W of us in a purely orographic situation.

This is what CMP is hoping for, and the result of that might be a tenth of an inch or more.