Category Archives: Cirrus clouds

This is a new category

Some recent clouds

May 24th:

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May 25th, yesterday, starting with sunrise color

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Later yesterday morning, some interesting “Altocumulocirrus”, a rare breed indeed, mocking/mimicking Altocumulus.

Maybe Cirrus floccus would come closest to the true name, but to every eye but that of a genuine cloud maven person, it would be deemed just “Altocumulus”.  Check these out to see how good you were–and NO correcting your cloud diaries!!!!

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5:47 AM. Two layers are visible, a distant Altocumulus castellanus one, and the higher, much higher, cirriform clouds resembling Altocumulus. If you don’t believe me, the sounding from the U of AZ is below.
The TUS balloon sounding for 5 AM AST yesterday. The Altocumulus patches were up around 16,000 feet, and the cirriform clouds around 33,000 feet and at about -50°C
The TUS balloon sounding for 5 AM AST yesterday. The Altocumulus patches were up around 16,000 feet, and the cirriform clouds around 33,000 feet and at about -50°C (-58°F).  Had to cuss that bit because I sensed some doubt out there.
6:38 AM. Same cloud layer. Seriously, how can you not call this "Altocumulus", it mimicks it so well. But these globules are all ice, no liquid water of course anywhere near -50°C unless we believe the reports of Simpson (1963) who purported liquid at -62°C. Nobody believed him though; me ,neither.
6:38 AM. Same cloud layer. Seriously, how can you not call this “Altocumulus”, it mimicks it so well. But these globules are all ice, no liquid water of course anywhere near -50°C unless we believe the reports of Simpson (1963) who purported liquid at -62°C. Nobody believed him though; me ,neither.
7:37 AM. Another view of this cirriform layer making a mockery out of Altocumlus. Note that there is that tiny bit of shading, too, in these cloudlets.
7:37 AM. Another view of this cirriform layer making a mockery out of Altocumlus. Note that there is that tiny bit of shading, too, in these cloudlets.
5:24 PM. The convection leading to cellular structure was still evident pretty much the whole day. Again, we have a problem. Shading like this is not officially permitted with in cirriform clouds except in the "spissatus" species. One would be thinking "Altostratus" here since that cloud is widespread and can have gray shading. When you look at the TUS sounding nearest this time, you find that the moisture is still contained in the upper reaches of the troposphere, where it was in the morning, and that would be in the "etage" for high clouds, 33,000 feet or so above sea level.
5:24 PM. The convection leading to cellular structure was still evident pretty much the whole day. Again, we have a problem. Shading like this is not officially permitted with in cirriform clouds except in the “spissatus” species. One would be thinking “Altostratus” here since that cloud is widespread and can have gray shading. When you look at the TUS sounding nearest this time, you find that the moisture is still contained in the upper reaches of the troposphere, where it was in the morning, and that would be in the “etage” for high clouds, 30,000 feet or so above sea level.
The TUS balloon sounding for 5 PM AST, May 25th. The temperature of that icy layer ranged from about -35°C on the bottom to -60° C at top.
The TUS balloon sounding for 5 PM AST, May 25th. The temperature of that icy layer ranged from about -35°C on the bottom to -60° C at top, so there would not be any liquid water in it even though is might appear in some places.  Where’s my Lear jet?  Need to check these things out and in a hurry!

Now for some prettiness from yesterday evening:

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The End

Sunset was pretty good; raindrops tomorrow morning? In nine days as well?

Haven’t had much to say, brain pretty empty again after the big review of the NAS 2003 review which really needed reviewing and commenting on real bad….

(More “late homework” in the offing.)

———————-

Nice sunset last night; we have had a series of pretty nice ones over the past few days.

April 26th. Sunset over the Charoulou Gap.
April 26th. Sunrise over the Charouleau Gap.
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Orangy mountains highlighted by a gap in the Altostratus layer that allowed the setting sun to shine through.
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7:04 PM. There was some turreting in this line of Altostratus that passed over, and because of those deeper tops, indicating stronger, if still slight updrafts, larger snow particles developed and produced this line of heavier virga underneath it.
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7:10 PM.
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A contrail that’s more than about ten minutes old, now, after the new Int. Cloud Atlas has been released, termed, Cirrus anthrogenitus, maybe castellanus in this case, too.

From IPS MeteoStar, this interesting map for tomorrow morning.

The orangy colors denote the strongest winds in “Jetty Jetstream”, and as you know, the colder, low clouds, ones capable of reaching the temperatures where ice forms, are contained within that ring of strongest winds at this level (500 mb).  So, while the models I have looked at so far have no rain here, I think there’s a pretty good chance of a rogue shower tomorrow morning anyway.  At least there should be some nice Stratocumulus/Cumulus tomorrow and some will have ice in them.   As you know, it’ll be awful windy today, too, maybe 40 mph or so in brief gusts here in The Heights of Sutherland.

Also will be looking for some nice lenticulars since “Jetty” will be right over us, but a little toward the warm side where lenticulars mostly occur.

Map valid for tomorrow morning at 5 AM AST.
Map valid for tomorrow morning at 5 AM AST.

In the meantime, spaghetti suggests a big trough in our area again about nine days from now.  The later ACTUAL model outputs don’t show much of anything.  What’s up with that?  I’m hanging with spaghetti that later model runs will indicate a strong trough, and at LEAST another pulse of cooler air, and another minor chance of rain as we are going to see today and especially tomorrow as when become within the “ring of winds” aloft.  Didn’t Johnny Cash sing something about that? Maybe it was Wall of Voodoo

Below, some spaghetti for you showing a big trough over Arizona and the Great Basin which is not much reflected in the actual models, as noted.  But, just watch my friend, how those model outputs will change to reflect a bigger trough about this time!

Valid at 5 PM May 7th.
Valid at 5 PM May 7th.

 

The End

 

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?

High cold ones, and lots of patterns in a complex sky

In particular, those Altocumulus clouds, “cold” Cirrocumulus (ones that transform to ice immediately),  and those “Altocumulocirrus” clouds combining  with  scenes of “regular” cirriform clouds.  Lots of interesting sights to have seen yesterday.  All these the result of marginal moisture aloft and strong winds, up around 100 mph at the highest Cirrus levels.

Let us begin as cloud maven folk by examining the late afternoon sounding launched from our Wildcat balloon launching machine at the University of Arizona, courtesy of IPS Meteostar:

The temperature and humidity profile obtained from a weather balloon launched at about 3:30 PM yesterday afternoon from the U of AZCats.
The temperature and humidity profile obtained from a weather balloon launched at about 3:30 PM yesterday afternoon from the U of AZCats with some suggested cloud levels.  The Altcoumulus level is in doubt. the others are pretty straight forward.  Notice how high those little Cu were yesterday afternoon, about 16,000 feet above sea level, or about  13,000 feet above Catalina, with bases at a cold -13°C or so.  No ice came out of those, though.  Likely droplets too small, or short-lived.
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6:45 PM. A very narrow line of Altocumulus castellanus and floccus virgae approaches Catalina.
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6:46 PM. Let us exercise our curiosity and examine this element in more detail below.
6:47 PM. Altocumulus floccus virgae. Another example of how the top of a storm, as here, can be composed of droplet cloud while the ice that forms in it falls out below. Here, the extreme dryness underneath the Altocu prevents long trails. The ice crystals wither so that they have almost no fallspeed soon after they have fallen out, leaving a flat bottom of tiny ice crystals.
6:47 PM. Altocumulus floccus virgae. Another example of how the top of a storm, as here, can be composed of droplet cloud while the ice that forms in it falls out below. Here, the extreme dryness underneath the Altocu prevents long trails. The ice crystals wither so that they have almost no fallspeed soon after they have fallen out, leaving a flat bottom of tiny ice crystals.  When you see tiny cloudlets like this spewing ice, you KNOW that the temperature has to be extremely low, and colder than -30° C (-22°C) would be a good starting guess.  Actually, guessing “-31.3° ” would be more impressive to your friends or neighbors….   It was a pretty scene, that’s for sure.
5:37 PM. Pretty iridescence occasionally erupted in newly formed Cirrocumulus, newly, as within seconds or in the last minute when the cloud droplets are extremely tiny, less than 10 microns in diameter. You don't see iridescence in clouds with droplets much larger than that.
5:37 PM. Pretty iridescence occasionally erupted in newly formed Cirrocumulus, newly, as within seconds or in the last minute when the cloud droplets are extremely tiny, less than 10 microns in diameter. You don’t see iridescence in clouds with droplets much larger than that.  And, it has to be pretty much overhead to get the best views.  Hope you saw those yesterday.
5:41 PM.
5:41 PM.
5:43 PM. ??????? These are little cloudlets of ice up at Cirrus levels, but it looks exaclty like a field of normal Altocumulus to the ordinary eye. "Altocumulocirrus"?
5:43 PM. ??????? These are little cloudlets of ice up at Cirrus levels, but it looks exaclty like a field of normal Altocumulus to the ordinary eye. “Altocumulocirrus”?  Without doubt this “ice” composition would be contested by other observers.  However, cloud-maven person’s interpretation should be used.  Now it is likely that the ice in these clouds first formed on what we deem as “cloud condensation nuclei”, and it might be likely that water saturation was reached.  But, if there was an instant of liquid, is certainly transitioned to ice in seconds since the temperatures at Cirrus levels were well below -40° C.   I don’t believe this was at the same level as the Altocu shown in the beginning of this writeup, yet it wasn’t as high as the highest Cirrus yesterday (up around the -50° C level).
6:07 PM. An example of how complicated the cloud scene was yesterday. The whitish clouds in rolls were icy cirriform clouds, and the delicated clouds were HIGHER Cirrocumulus and Cirrus. Cirrocumulus yesterday was indeed where most cloud schematics put it, at Cirrus levels, though probably half the time its in the mid-levels were Altocumulus clouds reside. So, with Altocumulus-like clouds at Cirrus levels and Cirrocu on top of Cirrus, it was really a crazy cloud day yesterday.
6:07 PM. An example of how complicated the cloud scene was yesterday. The whitish clouds in rolls were icy cirriform clouds, and the delicated clouds were HIGHER Cirrocumulus and Cirrus. Cirrocumulus yesterday was indeed where most cloud schematics put it, at Cirrus levels, though probably half the time its in the mid-levels were Altocumulus clouds reside. So, with Altocumulus-like clouds at Cirrus levels and Cirrocu on top of Cirrus, it was really a crazy cloud day yesterday.  At the very top of this photo were Altocu that were immediately ice clouds that might have comprised a separate third level of clouds.  Need a Lear jet to get there fast to resolve these many guesses.
5:07 PM. Jumping around in time.... These were some of the best scenes yesterday IMO, those oh-so-delicate patterns in those cold Cirrocumulus clouds, ones that transitioned to Cirrus clouds downwind.
5:07 PM. Jumping around in time here…. These were some of the best scenes yesterday IMO, those oh-so-delicate patterns in those cold Cirrocumulus clouds, ones that transitioned to Cirrus clouds downwind.
5:08 PM.
5:08 PM. Same patch Cirrocu.  Note Cirrus forming in the lower portion of this photo, once Cirrocu.  BTW, all power lines should be placed under ground.
2:29 PM. Amid some real Cumulus fractus was some Cirrus "cumulus mimicry" I've termed "Cumulo-cirrus". Can you spot the fakes at Cirrus levels? Its pretty hard.
2:29 PM. Amid some real Cumulus fractus was some Cirrus “cumulus mimicry” I’ve termed “Cumulo-cirrus”. Can you spot the fakes at Cirrus levels? Its pretty hard.
2:29 PM. OK, I give up. Here's a zoomed shot of Cumulus fractus mimicry by clouds at Cirrus levels. Might have been some droplets, too, before converting to ice.
2:29 PM. OK, I give up. Here’s a zoomed shot of Cumulus fractus mimicry by clouds at Cirrus levels. Might have been some droplets, too, before converting to ice.  These kinds of clouds suggest significant turbulence at this level, as would be in a regular Cumulus fractus cloud.

The weather way ahead

Still looking for that chance of rain before July….  haha

Troughy conditions will actually recur aloft over us over the next few weeks it seems, which means slight chances of rain, but periodic cold fronts passing by, mostly dry ones.  Best chance for rain still seems to be around the 20th, plus or minus a day or two, even though mod outputs have backed off that scene.  But, we have our spaghetti that tells us the models will likely bring back that threat around the 20th, even if some individual runs show nothing at all or only close calls.  We shall see if this interpretation has any credibility at all, won’t we?

Of note, Cal having big April in rain and snow after the gigantic January and February accumulations!  Looks like they’ll continue to get slugged by unusually strong storms, off and on, for another couple of weeks.  Water year totals are going to be truly gigantic.

The End

“Peru’s Niño”

I thought you’d like to read this (Peru’s Niño), forwarded to me by Niño expert, Nate M.   Pretty incredible to read about what is happening down there in the wake of the Big Niño of 2015-16,  which really turned out to be more of a couch potato in terms of weather production in the Great SW.

But, all this winter,  along the Equator near the coast of South America, there has been something we used to call an “El Niño”,  but is downplayed or ignored these days because of a new definition that seemed to explain more weather when it occurred, “Region 3.4” a large zone along the Equator WAY out in the Pacific rather than something near the South American coast (that zone now called, “Regions 1 and 2”),  as nicely illustrated by NOAA here.

But what has been the effect of what we might call the “Classic Niño”, a warm strip of water along the South American coast, one that doesn’t extend too far into the Pacific?  “Read all about it”, as they used to say.   Its pretty remarkable.

And here’s what the SST field looks like.  Its boiling down there off South America!  (Speaking figuratively, of course):

Sea surface temperature anomalies as of yesterday from the Navy!
Sea surface temperature anomalies as of yesterday from the Navy!  Wow.  That hot water is fueling giang Cumulonimbus clouds, ones that spew out huge anvils that can affect the weather in the mid-latitudes, disrupt the normal winter patterns of where highs and lows like to go.  Could such a warm anomaly, limited to the near coastal region of South America, have created this astounding winter in the West?

Peru’s Niño can be thought of as a “classic Niño”, the ones written about in the decades before about 1990 or so when the definition of what constituted a  NIño (or Niña) was expanded and delineated more sharply among several definitions that were floating around. We ended up focusing on a region WAY out in the Pacific Ocean called, “Region 3.4” that SEEMED to explain more over the prior years.

What’s so interesting about this is that the “Classic Niño” has been underway pretty much all this winter, and we’ve had, especially in California, a classic Niño response; that is,  abnormally heavy precip farther down the West Coast that no one anticipated.

Hmmmmm.

Well, the correlations with Cal precip and “classic Niño” occurrences will take a huge jump upward after THIS winter!

End of Statement (hand-waving)  on Niñoes.

——————————–

Local weather statement:  for immediate release

Cooler, fluctuating weather foretold here for that latter part of March, I don’t know how many weeks ago, is on the doorstep after the long, anomalously hot dry spell.  Poor wildflowers have been suffering, too, fading, looking a little stunted after a great beginning, one rivaling the great displays of 2010.

All of the local weatherfolk are on top of this now, and so no point recasting that stuff.  HECK, you can go to Weather Underground1
and get as “good as can be” forecast for Catalina (Sutherland Heights) out to ten days!  And, there’s nothing worse for a weather forecaster with forecasting in his blood, than to be excited about an “incoming” and when you mention it to a neighbor he replies, “Yeah, I heard about that already.  Supposed to get a quarter of an inch.”  There is no air whatsoever in the “balloon” after that.  So, if you have a weather-centric friend who says something about the upcoming weather, pretend that you haven’t heard about it yet, “DON’T say something as hurtful, as “Yeah, I heard about that already.”

So, here, we go the long route because most weatherfolk are afraid to go too far into the future because its often WRONG.  Our models tend to lie a lot after about even a week, so only the brave go out even ten days!

However, here, we go out as much as two weeks and more because its not a truly professional site but rather want to get something out there earlier than other people, sometimes called a “scoop” in the news and weather business.  That’s why our motto here is, “Right or wrong, you heard it here first!”  Furthermore, if a longer range forecast posted here is WRONG, you won’t hear about it anymore!

Cloud maven person will say this about the first incoming of several fronts:  comes in early Thursday morning, its strong!    Rainfall potential:  10% chance of less than 0.12 inches, 10% chance of more than 0.75 inches.  Best of those is the average, or about 0.4350 inches in this one.  It has great POTENTIAL to be a soaker, but mods have been all over the place; hence, the large range of potential amounts.  At least some measurable rain seems to be in the bag, a paper one please, because plastic is insidious.  Note, CMP’s forecast is more generous than that found in WU’s latest forecast for Catalinaland.

The weather WAY ahead, unprofessionally so

Let us look beyond the professional forecasting limits to April:

We know we got several storms/fronts zipping across AZ as March goes out like a lion, but what about April?

Looks like that pattern will continue into April with temperatures below normal for the first part.  The end of the unprofessional forecasting portion of this blog, though we do have our NOAA spaghetti to hang our umbrella on….  Check it out for about two weeks ahead.

Some clouds recent clouds, including a couple from yesterday

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2:33 PM.  Yesterday afternoon saw a few globs of lenticular forming on top of mini_Cumulus clouds, ones that made you think the summer rain season could be at hand, given the 90+ heat of yesterday around these parts.
12:52 PM.
12:52 PM.  A high  (above 30 kft above the ground) and cold (less than -40°C patch of Cirrocumulus cloud that is going to transition to CIrrus over the next 10-20 minutes.
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1:12 PM:  Later that same patch as those cloudlets spread out and merge into just an ordinary Cirrus after being that delicate-looking patch of Cirrocumulus. Most Cirrocumulus clouds are not this cold, but rather evaporate or fatten into larger elements of “Altocumulus” clouds, rather than transition to Cirrus.
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Had a nice sunset a couple days ago (15th), some liquid Altocumulus cloud slivers with higher Cirrus.

The End

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1Although “Weather Underground” might sound like an org has a radical origin, maybe something left over from the late 1960s, this particular one was NOT formed by 60s “weatherman” terrorists like Bill Ayers and Bernadine Dohrn (the link is for those of you who may have set trash cans on fire, as happened at San Jose State to protest the Vietnam War, to look back at those days in horror or nostalgia; take your pick) , but rather by genuine weather geeks (haha, I count myself among them, those that can’t get enough of weather, there can never be too much, like the guys mentioned in this “Cloud City” article.)

Catalina WY progress report; Cal WY update, too, since I grew up in Cal

I thought you’d like to see this:

As of the end of February 2017. We're pretty average, but it took some "heavy lifting" in December and January to get there.
As of the end of February 2017.  You can see were right about at the average for the Water Year,, but it took some “heavy lifting” in December and January to get there.

Doesn’t look promising for much rain here in Catalina in March, however.  No rain in sight through the next 10 days at least.

Let’s check our 7 inches with what’s happening upwind, say, in CALIFORNIA, and see if there’s been any drought relief there, through February,  via the CNRFC:

California water year totals through the end of February 2017. Note one station in the central Califorina coastal range is already over 100 inches!
California water year totals through the end of February 2017. Note one station in the central Califorina coastal range is already over 100 inches!  There are 20 stations already over 100 inches as can be seen from the table at right.  March looks to have substantial rains north of SFO, which will add appreciably to those highest totals.  Amazing!  You can go to the CNRFC and expand these interactive maps, btw.

As you are likely to know from many media stories last year, Cal was in a drought siege of five straight years,  with but got a little relief last year in the northern part thanks to help from  the giant Niño, one of the strongest ever.

Alas, it was one that failed to deliver as the big rain producer for the south half of Cal and the SW in general as was expected.

In case you’ve forgotten how bad things were in Cal, let us look back at what was being said, those horrific appearing drought maps,  and also how hopeful were were at the time  that the Big Niño would take a bit bite out of drought.  This is a really good article:

https://www.climate.gov/news-features/event-tracker/how-deep-precipitation-hole-california

Then, when the Big Niño faded away like maple syrup on a stack of buckwheat pancakes last spring and summer,  we were surely doomed for more dry years.  And, for a time, the dreaded cold tongue of water in the eastern equatorial region, the so-called, La Niña, started to develop, which would be no help at all for  a good rain season like a Big Niño is, usually.

The Niña faded away, too, to nothing as the winter went on, so we really didn’t have much going on in the tropical Pacific to help us figure out what kind of winter rainfall regime we were going to have om 2016-17.  Not having anything going on meant winter rainfall could go either way, a difficult to figure out situation for season forecasters.

In retrospect it is pretty astounding how big a signal must have been out there SOMEWHERE that this winter was going to be one for the history books on the West Coast in general, and in particular, for Californians.  Californians saw their drought chewed up and spit out in a single winter, including snow packs so high the height of some mountain peaks have been revised.  (I’m kidding.)

No one saw such an astounding winter coming.

This winter sure makes one think of the QBO (Quasi-biennenial Oscillation, one up there in the Stratosphere where there’s almost no air (haha, well, practically none)…  Did the QBO have a role in this astounding winter;  was there a delay in the effects of the Big Niño even without a bunch of convection in the eastern Pac tropics?  Doesn’t seem that could be right…

But, William “Bill” Lau, U of Maryland scientist,  reported some statistical evidence of  such a lag way back in ’88 due to a QBO connection of some kind and ENSO, no physical cause could be discerned, however,  not yet,  anyway.  Lau, 1988, is reprised below for readers who want to go deep:

Annual cycle, QBO, SO on global precip J Geophys Res 1988ocr

Sure has looked like the Big Niño WY we expected last year!

Some recent clouds; after all, this is CLOUD maven, not RAIN maven:

I’ve been kind of holding out on you.  I dropped my camera and busted it.  Its no fun taking pictures when you don’t have a real camera.  Still doesn’t work right, but take these anyway:

March 4th, afternoon. Hope you logged this; the rarely seen CIrrus castellanus (almost "congestus" in size) or, informally, "Cumulo-cirrus."
March 4th, afternoon. Hope you logged this; the rarely seen CIrrus castellanus (almost “congestus” in size) or, informally, “Cumulo-cirrus.”
Poppies are out, btw. Nice display on "Poppy Hils" just across and southwest of the Pima County Pistol Club, off Bowman.
Poppies are out, btw, in case you haven’t noticed. Nice display on “Poppy Hils” just across and southwest of the Pima County Pistol Club, off Bowman.
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March 4th, late afternoon. Nothing terrifically special in this tangle of Cirrus spissatus (“Cis spis” to cloud folk) but I thought it was just a really nice scene

Moving to the next day, Sunday, that REALLY windy day:

March 5, Sunday morning 6:13 AM. Altocumulus lenticularis alerts cloudwise folk to the possibility of windy conditions although it was already windy.
March 5, Sunday morning 6:13 AM. Altocumulus lenticularis alerts cloudwise folk to the possibility of windy conditions although it was already windy.
3:55 PM, March 5th. After a day of solid Altostratus overcast with underlying Cumulus and Stratocumulus, a layer of Altocumulus began to move in to add a little more interest to the sky.
3:55 PM, March 5th. After a day of solid Altostratus overcast with underlying Cumulus and Stratocumulus, a layer of Altocumulus began to move in to add a little more interest to the sky.
3:57 PM. Looking to the north revealed that some of the lower Cumulus/Stratocumulus complexes reached heights where ice could form. That smooth region on the bottom and right side of the cloud is a fall of ice from this cloud with a RW- (text for "light rainshower") if you like to text stuff) right below that. This is not a lot of ice and so you'd be thinking the cloud barely made that ice-forming temperature.
3:57 PM. Looking to the north revealed that some of the lower Cumulus/Stratocumulus complexes reached heights where ice could form. That smooth region on the bottom and right side of the cloud is a fall of ice from this cloud with a RW- (text for “light rainshower”) if you like to text stuff) right below that. This is not a lot of ice and so you’d be thinking the cloud barely made that ice-forming temperature.  CMP doesn’t think it was caused by an ice fallout from that higher layer, which sometimes can happen.  Let’s look at the most timely sounding, just to check.  From the real Cowboys at the University of Wyoming, this:
Ann 2017030600.72274.skewt.parc
The TUS sounding which I only now just saw, showing a vast separation between the lower Stratocumulus and the higher layers of Altocumlus and Altostratus on top. Note, too, that over TUS the tops of the lower cloud is not quite at -10°C the temperature we start to look for ice formation in AZ. However, our clouds were NW of that balloon sounding, and it would have been that tiny bit colder, and tops were also lifted some when they passed over the Tortolitas earlier, meaning that the tops of this complex were colder than -10° C (14° F) at some point.

Wow, too much information….after a hiatus in blogging I feel like that  Oroville Dam in California, metaphorically overflowing with too much hand-waving information.

6:03 PM, March 5. Its still real windy. Line of virga brought a few drops when it passed overhead at 6:30 PM.
6:03 PM, March 5. Its still real windy. Line of virga brought a few drops when it passed overhead at 6:30 PM.
6:04 PM. Nice dramatic shot toward Marana as the backside of the middle cloud layer approached allowing the sun to shine through.
6:04 PM. Nice dramatic shot toward Marana as the backside of the middle cloud layer approached allowing the sun to shine through.
6:09 PM. Virga getting closer. May have to park car outside to make sure I don't miss any drops!
6:09 PM. Virga getting closer. May have to park car outside to make sure I don’t miss any drops!
6:22 PM. SW-NE oriented virga strip about to pass overhead. Drops fell between 6:30 and 6:40 PM, but you had to be outside to notice, which you would have been as a proper CMJ eccentric.
6:22 PM. SW-NE oriented virga strip about to pass overhead. Drops fell between 6:30 and 6:40 PM, but you had to be outside to notice, which you would have been as a proper CMJ eccentric.  You would have WANTED that trace of rain report, maybe slackers would not have observed.
6:30 PM. Climax; the great sunset allowed by that backside clearing.
6:30 PM. Climax; the great sunset allowed by that backside clearing.

The End, at last!

Iridescence, jet streak Cirrus warn of overnight “middlin'” storm

I guess “billows” (“undulatus” in cloudspeak) two days ago in the late afternoon wasn’t enough of a sign that the weather was changing. Yesterday we had fast moving Cirrocumulus with rainbows in it, and as the sun was setting, “jet streak Cirrus”, a line of Cirrus clouds often seen in the very core of high altitude, powerful jet streams passed overhead.

How hard was the wind blowing up there in that Cirrus last evening? Oh, our Tuscon balloon sounding, lifting off around 3:30 PM, going up about a 1000 feet a minute to, indicates that the max wind up there at Cirrus level was 146 knots (just under 170 mph)! Yikes. Poor balloon.  Must be in France by now.

The storm has been a bit of a disappointment in rain production. We’ve only logged 0.22 inches1.  Not as much as foretold here, 0.33 inches, but that forecast was a better prediction than  by “Weather Underground Robotics” (0.58 inches).  Its great to beat a robot!

We had another sign yesterday in the fastest moving Cirrocumulus clouds I think you’ll ever see around here (about 100 mph), ones at just 18,000 feet above sea level, 15 kft above Catalina:   rainbows of color near the sun called iridescence (also called “irisation”).   Here, as is the norm here,  are a few too many shots of the same thing2.

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10:54 AM. The fist of weather is used as a prop to indicate that these colors are forming a ring around the sun.
10:54 AM. The fist of weather is used as a prop to indicate that these colors are forming a ring around the sun. Usually you try to find a light standard somewhere…maybe a “gopro cam on a stick” might do it. Just don’t look at the sun when you do this.
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10:57 AM.
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10:57 AM, pulling back some for perspective. As we often say here, “so pretty.” And look at how tiny the granulation is in this Cirrocumulus cloud is!

The colors themselves, of course,  don’t warn of something about to happen, but the fast movement from the southwest did; a powerful jet stream is over you.   That strong stream, the result of temperature gradients in the atmosphere, is dividing deep warm air from deep cold air, and steers the alternations of high and low pressure centers, and with those alternations of lows and highs along the jet stream, air is drawn from different latitude zones and the boundaries where those different masses of air meet at the surface, is called fronts.  Here, such as last night, its nearly always cold ones.

The rest of the day was pretty exciting, the wind arising suddenly yesterday morning, along with our usual great visibility, and darker blue wintertime skies, made the clouds stand out more.

7:56 AM. Looking to the west at a scattering of Stratocu patches.
7:56 AM. Looking to the west at a scattering of Stratocu patches.
7:57 AM. Highlight on the hills above Saddlebrook. Stratocumulus overhead.
7:57 AM. Highlight on the hills above Saddlebrook. Stratocumulus overhead.
8:42 AM. This patch of Stratocumulus was the result of a lift zone that often produces clouds headed our way in southwesterly flow. The difference here is how limited in size this patch was allowing you to see where that lift zone was. Downstream, though, descending motions creamed this cloud, one that sat there most of the early part of the day. Usually a whole layer is over us, with a clearing visible toward the SW horizon.
8:42 AM. This patch of Stratocumulus was the result of a lift zone that often produces clouds headed our way in southwesterly flow. The difference here is how limited in size this patch was allowing you to see where that lift zone was. Downstream, though, descending motions creamed this cloud, one that sat there most of the early part of the day. Usually a whole layer is over us, with a clearing visible toward the SW horizon.
11:02 AM. Still out there, still limited in size. Wind here now 20-30 mph with stronger puffs.
11:02 AM. Still out there pretty much near the same spot, still limited in size. Wind here now 20-30 mph with stronger puffs.

 

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11:40 AM. By this time it had shifted closer to us, still forming on the southwest end, dissipating at the downwind end where the cloud is so ragged due to mixing with dry, descending air.
12:42 PM. Creeping closer, but still a standing wave, dissipating as it came toward us.
12:42 PM. Creeping closer, but still a standing wave, dissipating as it came toward us.  It was about this time that it disappeared, the sky becoming more complex with no simple standing waves.

The sky at last, considering the power of the trough approaching, FINALLY began to fill in.  Started looking around for the first sign of ice having formed in these clouds as the air aloft became cooler. Along with this filling in by Cumulus and Stratocumulus clouds, some sun highlights began to appear on our mountains, contrasted by the darkening skies above.

1:55 PM. Stratocumulus banks up against the Catalinas, Samaniego Ridge.
1:55 PM. Stratocumulus clouds  bank up against the Catalinas, Samaniego Ridge.
2:03 PM. While Stratocumulus banked up against the mountains, huge temporary clearings occurred elsewhere. Notice how shredded the tops of these clouds are and how the tops lean to the right. They're revealing the great increase in the wind with height, and yet, how dry it was above this layer (that, by the ragged cloud tops mixing with the very dry air just above them.)
2:03 PM. While Stratocumulus banked up against the mountains, huge temporary clearings occurred elsewhere. Notice how shredded the tops of these clouds are and how the tops lean to the right. They’re revealing the great increase in the wind with height, and yet, how dry it was above this layer (that, by the ragged cloud tops mixing with the very dry air just above them.)
3:38 PM. Here comes the Jet Streak Cirrus! Also about this time, the frontal windshift line, marked by low scud clouds in the cold air, began to appear on the NW horizon. It was an exciting moment. Here we go! FROPA within a coupla hours maybe. Well, took longer than that....
3:38 PM. Here comes the Jet Streak Cirrus! Also about this time, the frontal windshift line, marked by low scud clouds in the cold air, began to appear on the NW horizon. It was an exciting moment. Here we go! FROPA within a coupla hours maybe. Well, took longer than that….
3:52 PM. A little ruffle of Cirrocumulus leads the advance of the jet streak Cirrus.
3:52 PM. A little ruffle of Cirrocumulus leads the advance of the jet streak Cirrus.
4:11 PM. Cloud line forming above the frontal windshift line. Was progressing this way at this time, but was to stall, maybe back off.
4:11 PM. Cloud line forming above the frontal windshift line. Was progressing this way at this time, but was to stall, maybe back off.
4:11 PM. Zooming, floating over Saddlebrooke, this close up of our FROPA and windshift line. Ended up backing off, dissipating, maybe reforming later after dark.
4:11 PM. Zooming, floating over Saddlebrooke, this close up of our FROPA and windshift line. Ended up backing off, dissipating, maybe reforming later after dark.  These lowest clouds form in the colder air associated with the windshift line at the nose of the front as the moist air ahead of the front  mixes with it and is lifted.  We see this with most of our incoming cold fronts, and in our summer thunderstorms.  The best cases  form “arcus clouds”, a solid line just above and behind the windshift at the ground.  These kinds of ragged clouds, in cloudspeak, are called “pannus.”  Was pretty excited here, as no doubt you were, that FROPA (frontal passage) was imminent, might happen within the hour.  Nope.
4:40 PM. In the meantime, our jet streak CIrrus moved overhead, the clearing behind this thin band leading to some memorable fading sun highlights on the Catalinas.
4:40 PM. In the meantime, our jet streak CIrrus, above the Stratocumulus clouds,  moved overhead, the clearing behind this thin band leading to some memorable fading sun highlights on the Catalinas.
5:40 PM. No words needed.
5:40 PM. No words needed.
5:43 PM. "Fading sun and rain gauge." Another one of those exceptional scenes you won't find anywhere except on this blog. Tell your friends. A small mammal, termed a "packrat" is decimating my prickly pear wind protection for this gauge! A lot of rain loss occurs due to wind. drops missing the collector! It very upsetting to see this happen.
5:43 PM. “Fading sun and rain gauge.” Another one of those exceptional scenes you won’t find anywhere except on this blog. Tell your friends. A small mammal, termed a “packrat” is decimating my prickly pear wind protection for this gauge! A lot of rain loss occurs due to wind. drops missing the collector! It very upsetting to see this happen.
5:43 PM. Even the often despised teddy bear cholla can be so beautiful in this fading sun, the spines capturing it so well.
5:43 PM. Even the often despised teddy bear cholla can be so beautiful in this fading sun, the spines capturing it so well.

Eventually our jet streak Cirrus provided the background for another great sunset scene:

5:56 PM.
5:56 PM.

 

 

A 300 millibar (about 30,000 feet above sea level) with an IR satellite image for yesterday at 5 PM AST. Arrows denoted the jet streak Cirrus cloud, enhanced in the downwind region of the Baja mountains.
A 300 millibar (about 30,000 feet above sea level) with an IR satellite image for yesterday at 5 PM AST.   The Cirrus layer extended from about this height to around 35, 000 feet above sea level.   according to our TUS balloon sounding.  Arrows denoted the jet streak Cirrus cloud thatpassed over us,  enhanced in the downwind region of the Baja mountains.  Note that the wind at San Diego max wind was even slightly stronger than our wind max was at this level at152 knots.  This map is the courtesy of the University of Washington Huskies Weather Department.

Today’s clouds and weather

From that map above, you’ll see that there’s a “tail-dragger” trough still to the west of us and about over Sandy Ego (haha). That’s going to keep the air over us extremely cold, and with some sun, the Cumulus clouds that arrive are expected to have tops colder than -15 to -20° C, plenty cold enough for the formation of ice.
Ice means precip, snow up there, rain down here in spots. So, we could still pick up a few more hundredths if a shower happens to drop by. The chance of isolated very light showers in the area is 100%, but no one can tell you if one will actually land on us. You’ll have to be watching, mostly after 12 noon. Look to the west toward the Tortolita Mountains, terrain that ought to spawn one or two of those.

Looks like a longer dry spell ahead; several days to a week, maybe more.

The End

—————————-

1CoCoRahs gauge, btw. NWS-style gauge had only 0.20 inches, likely due to enhanced wind loss associated with my collapsing prickly pear protector.
2 I was driving and had to park and jump out of car to get these.  You only have seconds or maybe a minute or three to capture stuff like this.

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