Definitions – Page 9

Altocumulus in transition; water to ice

I was thinking how great yesterday was for you. Started out with a spectacular sunrise (lasted just a couple of minutes), and then you could watch for pretty much the WHOLE day, orographically-formed Altocumulus opacus and castellanus transition to ice crystal clouds (in this case, Altostratus with virga and some mammatus) right before your eyes!

Sunrise:

7:16 AM. Flecks of Altocumulus clouds below Altostratus.

After sunrise….this odd scene below of an extended Altocu lenticular cloud:

12:24 PM. Altocumulus opacius shedding ice as they moved westward across Oro Valley.

3:01 PM. Altocumulus castellanus forming just upwind of the Catalinas, moving toward the west (to the left in this photo). No ice is falling out yet, though tiny ice crystals are likely starting to form.

3:01 PM. Looking farther downstream from the prior photo. Some ice is beginning to show up and fall out (center and left side of photo).

3:02 PM. Looking still farther downwind, those Altocumulus clouds are mostly glaciated, that is, mostly consist of ice. This transition has taken about 10 minutes of travel downwind. The sounding near this time, indicated that tops a little downwind of the U of AZ campus release site, were about -27°C (-17°F). However, tops were likely rising some small amount in this region downwind of the Catalinas, and so were almost surely, even a little colder than that.

4:33 PM. Nice example of what some of the Altocumulus castellanus looked like yesterday. That tallest turret will fall back. Its partner is just to the right, one that was previously as high, but fell back, its load of ice crystals drifing down. Some of the ice in the taller one is still being held up there until it, too, collapses. A error in aircraft sampling can occur if you don’t realize that tops have collapsed from lower temperatures, such as when collecting ice concentrations in the collapses one. You could easily assign a cloud top temperature that was too high; would not reflect the temperature at which they really formed.

More “pretties” below; yesterday’s sunset:

The afternoon sounding from the U of AZ campus.

The End

Intriguing jet stream pattern arises in computer models

First, your sunset for last evening:

5:38 PM. Altostratus with nearly straight lines of lower hanging virga in the distance. One cannot help but wonder if the passage of an aircraft enhanced the ice falling out and that’s why they are so linear. There were quite a few aircraft-induced lines of ice yesterday, but all developed in cold Altocumulus clouds. There’s one over there to the north….

5:33 PM. Lppking over there to the N and you can see a rivulet of ice falling below that patch of Altocumulus. one of many yesterday, though this is the prettiest one. You can also see that there is something “wrong” here. The trails below appearing to be slanting toward the west and the flow was from the east. This indicates that the flow was stronger at lower elevations, an oddity.

Brain’s been pretty empty lately, not much to say except “same old same old”, as here.

But then some wild computer forecasts came out last evening that were worth mentioning in light of the fires that have plagued southern California.

Why?

Because they suggest that a belt of tropical flow will break through under the gigantic ridge that has blocked storms from the entire West Coast over the past weeks.

Sometimes, as most weathermen know, such persistent ridges get too big for their britches, that is, over-extend to the north, and then fracture, letting through moist tropical air from lower latitudes of the Pacific ram into the West Coast. Often the very greatest rains in California are associated with such patterns, as you could guess since there is so much water with those lower latitude-originated jet streams that strike the coastal mountains head on. Here’s the concern, this output valid for Christmas Day:

This from last night’s 5 PM GFS global model run, valid for 5 PM AST Christmas Day. What is shown is that the tropical input is about to combine with a trough over the Bay Area. When this happens both are energized.

Rain is forecast to have fallen in southern Arizona before this point, however; our measly 0.01 inches so far here in Sutherland Heights so far in December will likely be added to along with a switch to uncomfortably cold weather.

Of course, we look for support in these longer range forecasts by having some spaghetti–that is, take a look at what we call “spaghetti”, those crazy plots in which the model starting conditions are tweaked that bit to see how the model runs change. Here are some plots, also from last night’s model.

As you can see in this first plot for the evening of December 22nd AST, the clustering of blue and red lines off the West Coast, that our blocking ridge (composed of a deep mass of warmer air) is extruding all the way almost to where Santa Claus lives, yes, that far to the north. In fact, so far that it will be unsustainable over that distance fromt the deep tropics to almost the North Pole. At this point, cold air is pouring down the east side of that ridge and into the Pac NW and eventually down toward us. Does that extremely cold air make it here? Not sure yet, but its something to watch out for before that ridge fractures and allows warmer, moist Pacific air to reach us. So much uncertainty, so much fun! I am really pumped up about all this uncertainty!

Valid at 5 PM December 22nd. This is really strong support for a major trough in the SW, and likely rain in southern AZ, Sutherland Heights around this time.

Below is the spaghetti dish for the “breakthrough” flow situation shown in the prog output valid for Christmas Day with some annotation on it.

Looking at the above, I think we can count on a breakthrough flow pattern from the Pac. Where it barges into the West Coast will be subject to question over the next week or so. That really can’t be determined right now.

I am sure those in southern Cal hope, if there is a breakthrough from the Pac, it comes in farther north than shown in the model run here today! Patterns like the one shown in that run can routinely produce 10 inches in a day once they get going should something burst through at low latitudes.

The brighter side would be that the chances of a significant rain here droughty southern AZ would at last increase.

The End

Icy clouds blot afternoon sun in Catalina for seventh day in a row! How weird is that?

Well, on some days, there were Altocumulus clouds, too, helping to blot the sun. Altocumulus clouds are mostly or all liquid clouds, if you care, which I doubt. But then you are here, wasting time on this web site about clouds, so maybe you do care!

But, to conitnue the title’s theme, what a remarkable streak here in the “Atacama Desert” of Arizona where it has been said that it has never rained. It certainly hasn’t rained here in recent memory. And, will we have a truly dismal wildflower display? Could be, due to the absence of fall rains that are so important in producing good displays.

And while there has been a pattern change, as there always is sooner or later, the conditions for rain just will not develop. We are now in a “warm in the West, cold in the East” pattern of jet stream flow, that the atmosphere seems to like; gets stuck in it for days to weeks at a time. A big ridge of high pressure will be deflecting the jet stream into Alaska and to where its toasty warm in “Utqiaġvik” (formerly Barrow; new name not pronounceable by non-native peoples–haha, just kidding, but what does that dot mean above the letter “g”?!) with lots of precip for them. Then that jet shoots down into the Rockies and upper Mid-West bringing masses of Arctic air and snow (the formerly warm air gets modified like mad when sitting on snow and ice–yes, there is still some ice and snow in Arctic regions, contrary to some popular beliefs). But, what about in 50 years? That is the question…

No rain shows up for southern Arizona for two more weeks in the models. Oh, me.

The only thing that will be fun in the next two weeks is looking at the hourly reports for Mount Washington, New Hampshire over the next two weeks, and see how cold and windy it gets. Do you know that once (1989) it was -44°C (-47°F) at Mt. Washington with winds of, oh, I dunno, 100 mph or so? Wind chill probably was around -500°F….. The craziest thing about that long ago ob was that they were reporting “icing”, liquid cloud drops hitting and freezing. But, how could they be liquid at -44°C?

Well, its been reported, strangely believe it, as we like to say here, that liquid drops have survived to between -40°F and -50°C by motorcycle-riding, atmospheric scientist, Kenneth Sassen, when he was at the University of Utah. Utah is located north of Arizona. Ken, if I may, thought it was due to sulfur in the droplets associated with volcanic aerosols, so it wasn’t “real” water, but rather the kind of water geoengineers want to inject to cool old mom earth. Maybe, if true, that icing report at Mt. Washington wasn’t “real” water, either, but polluted water from cities and factories to the NW where the wind came from….

BTW, when you get bored some more with our own weather, the obs for KMWN can be found here. You’ll be glad you’re in Arizona when you look at them. Well, you’ll be glad you’re anywhere but THERE! Maybe some geoengineers should spend some time up there instead of proposing crackpotty schemes that would change our sky color. I demand, as persons of the 1960s would, of course, that the people of earth be allowed to vote on such schemes BEFORE they are implemented!

Oh, yeah, about clouds…..after all, this is supposed to be, “cloud-maven” country…

3:36 PM yesterday. Once again, Altostratus translucidus (too gray to be Cirrus) has blotted the sun. The bottom of this layer was about 20,000 feet above Catalina, according to the balloon sounding yesterday afternoon.

The End, for now. Have some other chores to plug away on.

Pattern change in the works! Rain to fall in December!

Spaghetti. See spaghetti run. “Run, spaghetti, run!”¹

FINALLY, after almost a calendar year of dryness and warmth, a pattern change is definitely in the works that will bring rain and snow to Arizona, beginning in early December!

Here’s what we got now:

. Big hump o’ warm air over us for a few days. Red and blue lines represent jet stream positions, pretty much the outer (southern, red) and inner locations (blue, cold side of the jet.)

But, not so long from now, that big ol’ storm blocking hump of warm air over us melts away, and the jet stream begins barging into southern Cal and the Southwest, and with that, STORMS! Yay! Did you hear that desert?

But here’s what we got in early December, throwing in a little chaos. Looks pretty good, doesn’t it? Temperatures near normal or below, rain in the region at times. Note how red lines now dip down into Bajaland. Excellent depiction.

EOM

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¹Cribbed from the Hawaiian Pups, “Baby Judy.” not the baby reader, Dick and Jane at all…

A day dominated by cold Altocumulus punctuated by aircraft-produced hole punches and ice canals

Hope you saw them and recorded them in your cloud and weather diary. I’m thinking that at the next Cloud Maven Junior meeting we should devote a lot of time to this issue. It was a rare day yesterday that the WHOLE day had that phenomenon occurring as aircraft penetrated those clouds, usually on ascent or descent. Sharp descents/ascents produce holes. See the sequence below if you don’t believe me (ppt from a recent talk):

Aircraft inadvertent cloud seeding for Julie Mc.

Yesterday’s clouds: lots and lots of aircraft-produced ice

(btw, see note below about pop-up ads in this blog, ones that started to appear after downloading latest WP software)

6:44 AM. Altocumulus at sunrise. As we say so many times here in old AZzy, “So pretty.”

Also at 6:44 AM. From a smartphone, color not so great, though not bad either.

U of AZ Wildcats balloon sounding, launched at about 3:30 AM yesterday. Those Altcumulus clouds were way up there for Altocu, 22,000 feet above Catalina, 25,000 feet above sea level.because they were so high, were so cold, AND were composed of supercooled liquid water, they ripe for aircraft to create ice going through them, likely on climb out and descent from TUS and perhaps PHX as well, Davis-Monthan. What was unusual, was that it was happening most all day as the clouds filled in some. They remained liquid, high, and cold.

7:23 AM. Wasn’t long before aircraft made their presence known in this cold, cold layer.

6:54 AM. I should point out that a colder topped Altostratus layer was present to the N. Its not represented well in the TUS sounding. That layer was all or mostly all ice (the rosy colored segment of this photo).

7:37 AM. An unperturbed view of Altocumulus perlucidus (“Mackerel sky”). Are there any mackerel left? Also, from a cloud viewing standpoint, these are much higher than one would guess. The fact that aircraft were making ice in them is a clue that they were higher than we would normally think of a “middle-level” cloud. I like patterns like this. I thought you would like to know that about me.

9:03 AM. Slicing and dicing. An aircraft has left a contrail through a Altocumulus line . What’s really unusual here is the ice contrail so far outside the liquid water cloud. It is thought that hole-punch and ice canals are limited to regions where there are liquid droplets, and so this is quite an anomaly, one that suggests the humidity was almost 100% with respect to water outside the cloud boundaries. Also, can you just make out the partial 22° halo, indicating very simple ice crystals like columns and plates? Streamers of tiny ice crystals are also evident, trailing to the right, below the contrail? This shows that the wind decreased rapidly with height just below the flight level, but was still from the southwest to west.

9:24 AM. Coming at you, another ice-canal has formed SW-W of Catalina, a favored locale for the formation of these canals on days like this.

9:40 AM. What’s left of it is almost to Catalina. Note streamers of ice. Below, a close up of a couple.

9:40 AM. The intensity and narrowness of these streamers point to an artificial origin. So, even if you didn’t see the canal, and here, some of the clouds are reforming at the top of the streamer, you would make a good guess that this was not natural ice. Sometimes the canals can fill back in if the air is in overall ascent at cloud level.

9:57 AM. Here’s what those contrails in Altocumulus look like as they first appear. Can you spot’em? There are two.

1:45 PM. Another aircraft-produced ice event as the Altocumulus increased and became thicker, making detection of these events less obvious. Sometimes a canal clearing is very muted.

4:12 PM. Aircraft-induced hole punch cloud with ice below the hole. Can you spot it? See close up below.

4:12 PM. Close-up of that hole punch, ice mostly below the Altocumulus layer.

4:35 PM. That hole punch cloud 35 min later. The long trail indicates high humidity well below the Altocumulus layer in which it appeared.

The 3:30 PM balloon sounding from the U of AZ. A study in ambiguity.

The day ended with an unusually bright sun dawg, mock sun, or parhelia. So bright it did, again, suggest a plume of ice from a prior aircraft passage through extra cold Altocu or Cirrocu clouds. But, just wild speculation here. Hope you don’t mind.

5:41 PM. Nice sunset, but one strongly impacted by clearing from aircraft-produced holes and lines of ice, the ice now mostly gone.

The End

——————About those nuisance ads—————

Note to me and the two other people that drop by my cloud or “clod” blogulations: The embedded pop-up ads are due to a WP third party plug-in that needs to be repaired. It will likely happen today.

After consultations about ads…

Oddly, those pop-ups and blue highlighting and double underlining do not seem to be present outside of my personal view of my own blog, this according to hoster, “godaddy.” Even using a different browser other than FIrefox does not show them as I have just verified.

Some recent pretty clods

Been busy as a briefly unretired science worker (gave a stressful talk at a university last week) and thought maybe a lot of usual drop ins to this site might not anymore. So, in the title for today, am reaching out to a new demographic: persons interested in congealed soil matter. They might later, after stopping by, discover a new interest; that in clouds, pretty ones. Most of the cheap tricks I try like this don’t have any effect, though. Oh, well.

Let us go forward after backing up:

November 3rd

8:02 AM. Looking SW from Catalina. So pretty with the deep blue skies we have at this time of year due to sun’s lower angle in the sky.

9:16 AM. Look how different, even unreal, that flock of Cirrus looked when leaving us. Looking NE toward the Charouleau Gap.

But the Cirrus kept coming and more odd sights were seen:

10:06 AM. Two levels of Cirrus can be seen. This vertical white patch is likely a few thousand feet lower than the crossing faint strands center and right side, which are likely above 30,000 feet above the ground. The heavier Cirrus (spissatus) in the distance is also lower than the strands.

Heavier Cirrus, increasing and lowering to Altostratus finished off the day as a heavy shield of middle and upper clouds raced toward southern Arizona from the Pacific:

3:08 PM. Cirrus spissatus here, too splotchy in coverage to be Altostratus. Nice subtle lighting effect on the Catalinas…

“Due to time constraints, we move ahead in the action…”

November 4th

7:27 AM. Classic A row of Altocumulus floccus and castellanus underlie an Altostratus layer. Where the bases have disappeared, at right, are termed “floccus”, if you care.

8:00 AM. Altostratus, some lower Altocumulus castellanus with graniteen boulders and a coupla saguaros.

8:59 AM. Bird collective watches in hopes that the darkening, lowering Altostratus layer (with some Altocumulus) will bring rain. It didn’t. “Dang”, we say here.

4:51 PM. All of the higher layers were gone, leaving only a lowest, but thin scattered to broken Stratocumulus clouds. 🙁 All in all, it was a good day for hiking and other outdoor activities.

Sunday, November 5th:

6:01 AM. Flock of CIrrus uncinus and spissatus again advances on Catalina.

6:21 AM. a closer view. Here they seem to be uncinus with fibratus. Stratocumulus clouds were topping the Catalinas, too, indicating more humidity than we have been seeing most of the past few weeks.

8:38 AM. I thought this was an especially spectacular scene, this lattice of Cirrus racing toward us. Hope you did, too.

4:26 PM. Perhaps the brightest example of iridescence I have ever seen! Just spectacular for a few seconds in this patch of Cirrocumulus. Iridescence is caused by diffraction around the tiny of droplets, less than 10 microns in diameter, as are present when a cloud just forms.

5:09 PM. Seeing this scene of Altocumulus, you KNEW you were in for a superb sunset. It didn’t disappoint.

The weather just ahead

The Wildcat Weather Department model is foretelling perhaps a measurable rain event between this afternoon and tomorrow morning at 7 AM! Heavier rain is foretold to be south of us, but just a slight error would mean something more substantial. Hoping for error! A sky covering Altostratus layer is just about assured with a lowering tendency as the day goes on. Should see some Altocu , too, a day a lot like last Saturday.

The End

Raindrops fall on Catalina ending rainless October

A trace of rain was officially recorded in Catalina at this site ending prospects of a rainless October. It fell from high-based Cumulonimbus clouds in a band, partially lining the NW horizon that could be seen as the sun rose yesterday. Some ants were injured by the falling drops, ones that reached millimeter sizes and fell at 5-8 mph, though in some areas, winds of 10-15 mph added to drop impacts. Flying insects, while obliged to avoid the watery missiles, were able to do so with ease due to the appreciable spacing between the drops of several feet.

Due to the short-lived hydrometeor events, many humans were unaware that rain had fallen in Catalina on more than one occasion yesterday. That’s why we blog here. Weather and cloud news you can rely on.

How high were the bases of those precipitating clouds spewing snow virga that melted to rain? Higher than the freezing level! Haha.. The balloon sounding profile started with the Altocumulus perlucidus layer at 18,000 feet above sea level, 15,000 feet above Catalina, bases at -11°C. By evening the lowest moist level had lowered to 14,000 feet ASL (11,000 feet AGL) and -3°C. However, that last moist level had to be a bit lower than those snowy cloud bases IMO–we know that the moist level almost always lowers.

So cloud maven person will make the definitive call that the rainy (well, sprinkly) cloud bases were at 16,000 ASL (13,000 feet AGL) when they passed over, if that makes any sense or is anything you really care about.

Yesterday’s clouds

6:42 AM. Altocumulus perlucidus at -11°C (12°F). No ice evident.

6:43 AM. High-based Cumulonimbus erupts to the distant NW. Altocumulus castellanus layer from which it erupted can also be seen. The snow falling from cloud base is also evident, melting to rain just above the horizon.

6:54 AM. By this time the full band to the NW whose tail was to pass over us about mid-day is evident. Plenty of snow can be seen falling from these modest, high-based Cumulonimbus clouds.

As rain fell……this sky, 12:30 to 1 PM:

Kind of pathetic really; no shafting whatsoever, much less virga than on the horizon yesterday morning. So our end of that band was so weak it was just barely able to get some drops to the ground.

Looks like this is it for rain in October 2017. However, November 2017 appears to look much brighter for substantial, dust-removing rains in Catalina beginning in the first 10 days!

The End (I missed the sunset due to a social engagement–hope you saw it wherever you were). Probably was pretty nice.

A study in cold Altocumulus and about a balloon mistaken for a space object

Balloon sounding released from the U of AZ about 3:30 PM AST. Altocumulus clouds were no less than 21,000 feet above Catalina at -20°C (4°F). Sounding courtesy of IPS Meteostar. BTW, it wasn’t this balloon–see below.

11:15 AM. A stationary balloon that hovers SE of Tucson. Can you find it? I had never noticed it before and at first thought it was in space, above the Cirrus! How crazy was that? Likely to be a device up there to monitor the US Border.

2:55 PM. Cirrocumulus with an aircraft produced ice canal in it , tight half of photo (that ice cloud now termed, “Cirrus anthropogenitus”).

4:02 PM. A complex sky for sure. Little tufts of Altocumulus way up at 21,000 feet above ground level, with Ac castellanus turrets (e.g., left above horizon). SInce those turrets are reaching up to temperatures well below -30°C (-22°F) they’re converting to all ice (such as center right). Those icy ones would be called, “Cirrus spissatus.” It would also not be untoward, and I know you don’t want that, to just call those deeper clouds with turrets on the left, “Cirrus castellanus.”

5:56 PM. Lines of Altocumulus make for an OK sunset.

Another pretty cloud day ahead. Though most of the Altocumulus clouds are flat, there are some whoppers off to the north now, Ac cas so large they might have to be called Cumulonimbus, certainly large enough to produce radar echoes, maybe a sprinkle at the ground.

Lots of wind tomorrow, as you likely know, but no rain in sight still. So, October almost surely will end as a rainless month. Our average for October is just over an inch of rain!

The End

Pretty sunrises/sunsets ahead and that’s about it for October

Footnote

A warm, rainless October appears to be our fate, much like last year when only 0.01 inches fell. Oh, me. Our dryness since the end of July, with so many cloudless skies, continues on and on. Tough to take if you’re cloud-centric.

However, this month, though likely rainless, promises to deliver some great sunrises and sunsets as weak regions of rising air pass above us in the days ahead, that rising air showing up as lots of middle and upper level clouds like Altocumulus, Altostratus with virga, and CIrrus over many of the remaining days. Those kinds of clouds can be associated with the most spectacular ones sunrises and sunsets.

I guess that’s something.

Below, a sample pretty scene for cloud-starved readers.

Taken by the Arthur on a University of Washington research flight in the early 1990s. The scene is the Willapa Bay Wildlife Refuge, Washington. We were studying the lifecycle of Cumulus clouds and the aerosol environments affecting them. On this calm day, Cumulus could form over the tiniest strips of warmer land. You would not see this scene on a windy day. So, the shot is not only “pretty”, but an unusual one. I was so lucky to have seen so many pretty scenes in research!

The End

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Again, pardon the links to ads. I have nothing to do with them. Will make them go away via $$ in the days ahead.

The 2016-17 Water Year for Catalina and how it compares to prior years

There are links appearing below in the online version that I have not added! Please ignore them until I find out what WordPress has done!

Blog as originally written, below:

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This is all I have for now. Am catching up after a long absence due to computer issues.

Advice: its best to never upgrade, and, “If its not broke, don’t fix it.”

Weather station still offline…. “:(”

The End